org.apache.commons.io

Class IOUtils


  • public class IOUtils
    extends Object
    General IO stream manipulation utilities.

    This class provides static utility methods for input/output operations.

    • [Deprecated] closeQuietly - these methods close a stream ignoring nulls and exceptions
    • toXxx/read - these methods read data from a stream
    • write - these methods write data to a stream
    • copy - these methods copy all the data from one stream to another
    • contentEquals - these methods compare the content of two streams

    The byte-to-char methods and char-to-byte methods involve a conversion step. Two methods are provided in each case, one that uses the platform default encoding and the other which allows you to specify an encoding. You are encouraged to always specify an encoding because relying on the platform default can lead to unexpected results, for example when moving from development to production.

    All the methods in this class that read a stream are buffered internally. This means that there is no cause to use a BufferedInputStream or BufferedReader. The default buffer size of 4K has been shown to be efficient in tests.

    The various copy methods all delegate the actual copying to one of the following methods:

    For example, copy(InputStream, OutputStream) calls copyLarge(InputStream, OutputStream) which calls copy(InputStream, OutputStream, int) which creates the buffer and calls copyLarge(InputStream, OutputStream, byte[]).

    Applications can re-use buffers by using the underlying methods directly. This may improve performance for applications that need to do a lot of copying.

    Wherever possible, the methods in this class do not flush or close the stream. This is to avoid making non-portable assumptions about the streams' origin and further use. Thus the caller is still responsible for closing streams after use.

    Origin of code: Excalibur.

    • Field Detail

      • DEFAULT_BUFFER_SIZE

        public static final int DEFAULT_BUFFER_SIZE
        The default buffer size (8192) to use in copy methods.
        See Also:
        Constant Field Values
      • DIR_SEPARATOR

        public static final char DIR_SEPARATOR
        The system directory separator character.
      • DIR_SEPARATOR_UNIX

        public static final char DIR_SEPARATOR_UNIX
        The Unix directory separator character.
        See Also:
        Constant Field Values
      • DIR_SEPARATOR_WINDOWS

        public static final char DIR_SEPARATOR_WINDOWS
        The Windows directory separator character.
        See Also:
        Constant Field Values
      • EMPTY_BYTE_ARRAY

        public static final byte[] EMPTY_BYTE_ARRAY
        A singleton empty byte array.
        Since:
        2.9.0
      • EOF

        public static final int EOF
        Represents the end-of-file (or stream).
        Since:
        2.5 (made public)
        See Also:
        Constant Field Values
    • Constructor Detail

      • IOUtils

        public IOUtils()
        Instances should NOT be constructed in standard programming.
    • Method Detail

      • buffer

        public static BufferedInputStream buffer(InputStream inputStream)
        Returns the given InputStream if it is already a BufferedInputStream, otherwise creates a BufferedInputStream from the given InputStream.
        Parameters:
        inputStream - the InputStream to wrap or return (not null)
        Returns:
        the given InputStream or a new BufferedInputStream for the given InputStream
        Throws:
        NullPointerException - if the input parameter is null
        Since:
        2.5
      • buffer

        public static BufferedInputStream buffer(InputStream inputStream,
                                                 int size)
        Returns the given InputStream if it is already a BufferedInputStream, otherwise creates a BufferedInputStream from the given InputStream.
        Parameters:
        inputStream - the InputStream to wrap or return (not null)
        size - the buffer size, if a new BufferedInputStream is created.
        Returns:
        the given InputStream or a new BufferedInputStream for the given InputStream
        Throws:
        NullPointerException - if the input parameter is null
        Since:
        2.5
      • buffer

        public static BufferedOutputStream buffer(OutputStream outputStream,
                                                  int size)
        Returns the given OutputStream if it is already a BufferedOutputStream, otherwise creates a BufferedOutputStream from the given OutputStream.
        Parameters:
        outputStream - the OutputStream to wrap or return (not null)
        size - the buffer size, if a new BufferedOutputStream is created.
        Returns:
        the given OutputStream or a new BufferedOutputStream for the given OutputStream
        Throws:
        NullPointerException - if the input parameter is null
        Since:
        2.5
      • buffer

        public static BufferedReader buffer(Reader reader)
        Returns the given reader if it is already a BufferedReader, otherwise creates a BufferedReader from the given reader.
        Parameters:
        reader - the reader to wrap or return (not null)
        Returns:
        the given reader or a new BufferedReader for the given reader
        Throws:
        NullPointerException - if the input parameter is null
        Since:
        2.5
      • buffer

        public static BufferedReader buffer(Reader reader,
                                            int size)
        Returns the given reader if it is already a BufferedReader, otherwise creates a BufferedReader from the given reader.
        Parameters:
        reader - the reader to wrap or return (not null)
        size - the buffer size, if a new BufferedReader is created.
        Returns:
        the given reader or a new BufferedReader for the given reader
        Throws:
        NullPointerException - if the input parameter is null
        Since:
        2.5
      • buffer

        public static BufferedWriter buffer(Writer writer)
        Returns the given Writer if it is already a BufferedWriter, otherwise creates a BufferedWriter from the given Writer.
        Parameters:
        writer - the Writer to wrap or return (not null)
        Returns:
        the given Writer or a new BufferedWriter for the given Writer
        Throws:
        NullPointerException - if the input parameter is null
        Since:
        2.5
      • buffer

        public static BufferedWriter buffer(Writer writer,
                                            int size)
        Returns the given Writer if it is already a BufferedWriter, otherwise creates a BufferedWriter from the given Writer.
        Parameters:
        writer - the Writer to wrap or return (not null)
        size - the buffer size, if a new BufferedWriter is created.
        Returns:
        the given Writer or a new BufferedWriter for the given Writer
        Throws:
        NullPointerException - if the input parameter is null
        Since:
        2.5
      • byteArray

        public static byte[] byteArray(int size)
        Returns a new byte array of the given size. TODO Consider guarding or warning against large allocations...
        Parameters:
        size - array size.
        Returns:
        a new byte array of the given size.
        Since:
        2.9.0
      • close

        public static void close(Closeable closeable)
                          throws IOException
        Closes the given Closeable as a null-safe operation.
        Parameters:
        closeable - The resource to close, may be null.
        Throws:
        IOException - if an I/O error occurs.
        Since:
        2.7
      • close

        public static void close(Closeable... closeables)
                          throws IOException
        Closes the given Closeable as a null-safe operation.
        Parameters:
        closeables - The resource(s) to close, may be null.
        Throws:
        IOException - if an I/O error occurs.
        Since:
        2.8.0
      • close

        public static void close(URLConnection conn)
        Closes a URLConnection.
        Parameters:
        conn - the connection to close.
        Since:
        2.4
      • closeQuietly

        public static void closeQuietly(Closeable closeable)
        Closes a Closeable unconditionally.

        Equivalent to Closeable.close(), except any exceptions will be ignored. This is typically used in finally blocks.

        Example code:

         Closeable closeable = null;
         try {
             closeable = new FileReader("foo.txt");
             // process closeable
             closeable.close();
         } catch (Exception e) {
             // error handling
         } finally {
             IOUtils.closeQuietly(closeable);
         }
         

        Closing all streams:

         try {
             return IOUtils.copy(inputStream, outputStream);
         } finally {
             IOUtils.closeQuietly(inputStream);
             IOUtils.closeQuietly(outputStream);
         }
         

        Also consider using a try-with-resources statement where appropriate.

        Parameters:
        closeable - the objects to close, may be null or already closed
        Since:
        2.0
        See Also:
        Throwable.addSuppressed(java.lang.Throwable)
      • closeQuietly

        public static void closeQuietly(Closeable... closeables)
        Closes a Closeable unconditionally.

        Equivalent to Closeable.close(), except any exceptions will be ignored.

        This is typically used in finally blocks to ensure that the closeable is closed even if an Exception was thrown before the normal close statement was reached.
        It should not be used to replace the close statement(s) which should be present for the non-exceptional case.
        It is only intended to simplify tidying up where normal processing has already failed and reporting close failure as well is not necessary or useful.

        Example code:

         Closeable closeable = null;
         try {
             closeable = new FileReader("foo.txt");
             // processing using the closeable; may throw an Exception
             closeable.close(); // Normal close - exceptions not ignored
         } catch (Exception e) {
             // error handling
         } finally {
             IOUtils.closeQuietly(closeable); // In case normal close was skipped due to Exception
         }
         

        Closing all streams:

         try {
             return IOUtils.copy(inputStream, outputStream);
         } finally {
             IOUtils.closeQuietly(inputStream, outputStream);
         }
         

        Also consider using a try-with-resources statement where appropriate.

        Parameters:
        closeables - the objects to close, may be null or already closed
        Since:
        2.5
        See Also:
        closeQuietly(Closeable), Throwable.addSuppressed(java.lang.Throwable)
      • closeQuietly

        public static void closeQuietly(Closeable closeable,
                                        Consumer<IOException> consumer)
        Closes the given Closeable as a null-safe operation while consuming IOException by the given consumer.
        Parameters:
        closeable - The resource to close, may be null.
        consumer - Consumes the IOException thrown by Closeable.close().
        Since:
        2.7
      • closeQuietly

        public static void closeQuietly(InputStream input)
        Closes an InputStream unconditionally.

        Equivalent to InputStream.close(), except any exceptions will be ignored. This is typically used in finally blocks.

        Example code:

           byte[] data = new byte[1024];
           InputStream in = null;
           try {
               in = new FileInputStream("foo.txt");
               in.read(data);
               in.close(); //close errors are handled
           } catch (Exception e) {
               // error handling
           } finally {
               IOUtils.closeQuietly(in);
           }
         

        Also consider using a try-with-resources statement where appropriate.

        Parameters:
        input - the InputStream to close, may be null or already closed
        See Also:
        Throwable.addSuppressed(java.lang.Throwable)
      • closeQuietly

        public static void closeQuietly(OutputStream output)
        Closes an OutputStream unconditionally.

        Equivalent to OutputStream.close(), except any exceptions will be ignored. This is typically used in finally blocks.

        Example code:

         byte[] data = "Hello, World".getBytes();
        
         OutputStream out = null;
         try {
             out = new FileOutputStream("foo.txt");
             out.write(data);
             out.close(); //close errors are handled
         } catch (IOException e) {
             // error handling
         } finally {
             IOUtils.closeQuietly(out);
         }
         

        Also consider using a try-with-resources statement where appropriate.

        Parameters:
        output - the OutputStream to close, may be null or already closed
        See Also:
        Throwable.addSuppressed(java.lang.Throwable)
      • closeQuietly

        public static void closeQuietly(Reader reader)
        Closes an Reader unconditionally.

        Equivalent to Reader.close(), except any exceptions will be ignored. This is typically used in finally blocks.

        Example code:

           char[] data = new char[1024];
           Reader in = null;
           try {
               in = new FileReader("foo.txt");
               in.read(data);
               in.close(); //close errors are handled
           } catch (Exception e) {
               // error handling
           } finally {
               IOUtils.closeQuietly(in);
           }
         

        Also consider using a try-with-resources statement where appropriate.

        Parameters:
        reader - the Reader to close, may be null or already closed
        See Also:
        Throwable.addSuppressed(java.lang.Throwable)
      • closeQuietly

        public static void closeQuietly(Selector selector)
        Closes a Selector unconditionally.

        Equivalent to Selector.close(), except any exceptions will be ignored. This is typically used in finally blocks.

        Example code:

           Selector selector = null;
           try {
               selector = Selector.open();
               // process socket
        
           } catch (Exception e) {
               // error handling
           } finally {
               IOUtils.closeQuietly(selector);
           }
         

        Also consider using a try-with-resources statement where appropriate.

        Parameters:
        selector - the Selector to close, may be null or already closed
        Since:
        2.2
        See Also:
        Throwable.addSuppressed(java.lang.Throwable)
      • closeQuietly

        public static void closeQuietly(ServerSocket serverSocket)
        Closes a ServerSocket unconditionally.

        Equivalent to ServerSocket.close(), except any exceptions will be ignored. This is typically used in finally blocks.

        Example code:

           ServerSocket socket = null;
           try {
               socket = new ServerSocket();
               // process socket
               socket.close();
           } catch (Exception e) {
               // error handling
           } finally {
               IOUtils.closeQuietly(socket);
           }
         

        Also consider using a try-with-resources statement where appropriate.

        Parameters:
        serverSocket - the ServerSocket to close, may be null or already closed
        Since:
        2.2
        See Also:
        Throwable.addSuppressed(java.lang.Throwable)
      • closeQuietly

        public static void closeQuietly(Socket socket)
        Closes a Socket unconditionally.

        Equivalent to Socket.close(), except any exceptions will be ignored. This is typically used in finally blocks.

        Example code:

           Socket socket = null;
           try {
               socket = new Socket("http://www.foo.com/", 80);
               // process socket
               socket.close();
           } catch (Exception e) {
               // error handling
           } finally {
               IOUtils.closeQuietly(socket);
           }
         

        Also consider using a try-with-resources statement where appropriate.

        Parameters:
        socket - the Socket to close, may be null or already closed
        Since:
        2.0
        See Also:
        Throwable.addSuppressed(java.lang.Throwable)
      • closeQuietly

        public static void closeQuietly(Writer writer)
        Closes an Writer unconditionally.

        Equivalent to Writer.close(), except any exceptions will be ignored. This is typically used in finally blocks.

        Example code:

           Writer out = null;
           try {
               out = new StringWriter();
               out.write("Hello World");
               out.close(); //close errors are handled
           } catch (Exception e) {
               // error handling
           } finally {
               IOUtils.closeQuietly(out);
           }
         

        Also consider using a try-with-resources statement where appropriate.

        Parameters:
        writer - the Writer to close, may be null or already closed
        See Also:
        Throwable.addSuppressed(java.lang.Throwable)
      • contentEquals

        public static boolean contentEquals(InputStream input1,
                                            InputStream input2)
                                     throws IOException
        Compares the contents of two Streams to determine if they are equal or not.

        This method buffers the input internally using BufferedInputStream if they are not already buffered.

        Parameters:
        input1 - the first stream
        input2 - the second stream
        Returns:
        true if the content of the streams are equal or they both don't exist, false otherwise
        Throws:
        NullPointerException - if either input is null
        IOException - if an I/O error occurs
      • contentEquals

        public static boolean contentEquals(Reader input1,
                                            Reader input2)
                                     throws IOException
        Compares the contents of two Readers to determine if they are equal or not.

        This method buffers the input internally using BufferedReader if they are not already buffered.

        Parameters:
        input1 - the first reader
        input2 - the second reader
        Returns:
        true if the content of the readers are equal or they both don't exist, false otherwise
        Throws:
        NullPointerException - if either input is null
        IOException - if an I/O error occurs
        Since:
        1.1
      • contentEqualsIgnoreEOL

        public static boolean contentEqualsIgnoreEOL(Reader reader1,
                                                     Reader reader2)
                                              throws IOException
        Compares the contents of two Readers to determine if they are equal or not, ignoring EOL characters.

        This method buffers the input internally using BufferedReader if they are not already buffered.

        Parameters:
        reader1 - the first reader
        reader2 - the second reader
        Returns:
        true if the content of the readers are equal (ignoring EOL differences), false otherwise
        Throws:
        NullPointerException - if either input is null
        IOException - if an I/O error occurs
        Since:
        2.2
      • copy

        public static int copy(InputStream inputStream,
                               OutputStream outputStream)
                        throws IOException
        Copies bytes from an InputStream to an OutputStream.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Large streams (over 2GB) will return a bytes copied value of -1 after the copy has completed since the correct number of bytes cannot be returned as an int. For large streams use the copyLarge(InputStream, OutputStream) method.

        Parameters:
        inputStream - the InputStream to read.
        outputStream - the OutputStream to write.
        Returns:
        the number of bytes copied, or -1 if greater than Integer.MAX_VALUE.
        Throws:
        NullPointerException - if the InputStream is null.
        NullPointerException - if the OutputStream is null.
        IOException - if an I/O error occurs.
        Since:
        1.1
      • copy

        public static long copy(InputStream inputStream,
                                OutputStream outputStream,
                                int bufferSize)
                         throws IOException
        Copies bytes from an InputStream to an OutputStream using an internal buffer of the given size.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        inputStream - the InputStream to read.
        outputStream - the OutputStream to write to
        bufferSize - the bufferSize used to copy from the input to the output
        Returns:
        the number of bytes copied.
        Throws:
        NullPointerException - if the InputStream is null.
        NullPointerException - if the OutputStream is null.
        IOException - if an I/O error occurs.
        Since:
        2.5
      • copy

        public static void copy(InputStream input,
                                Writer writer,
                                Charset inputCharset)
                         throws IOException
        Copies bytes from an InputStream to chars on a Writer using the specified character encoding.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        This method uses InputStreamReader.

        Parameters:
        input - the InputStream to read from
        writer - the Writer to write to
        inputCharset - the charset to use for the input stream, null means platform default
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        2.3
      • copy

        public static void copy(InputStream input,
                                Writer writer,
                                String inputCharsetName)
                         throws IOException
        Copies bytes from an InputStream to chars on a Writer using the specified character encoding.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Character encoding names can be found at IANA.

        This method uses InputStreamReader.

        Parameters:
        input - the InputStream to read from
        writer - the Writer to write to
        inputCharsetName - the name of the requested charset for the InputStream, null means platform default
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
        Since:
        1.1
      • copy

        public static long copy(Reader reader,
                                Appendable output)
                         throws IOException
        Copies chars from a Reader to a Appendable.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Large streams (over 2GB) will return a chars copied value of -1 after the copy has completed since the correct number of chars cannot be returned as an int. For large streams use the copyLarge(Reader, Writer) method.

        Parameters:
        reader - the Reader to read from
        output - the Appendable to write to
        Returns:
        the number of characters copied, or -1 if > Integer.MAX_VALUE
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        2.7
      • copy

        public static long copy(Reader reader,
                                Appendable output,
                                CharBuffer buffer)
                         throws IOException
        Copies chars from a Reader to an Appendable.

        This method uses the provided buffer, so there is no need to use a BufferedReader.

        Parameters:
        reader - the Reader to read from
        output - the Appendable to write to
        buffer - the buffer to be used for the copy
        Returns:
        the number of characters copied
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        2.7
      • copy

        @Deprecated
        public static void copy(Reader reader,
                                            OutputStream output)
                                     throws IOException
        Deprecated.  2.5 use copy(Reader, OutputStream, Charset) instead
        Copies chars from a Reader to bytes on an OutputStream using the default character encoding of the platform, and calling flush.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Due to the implementation of OutputStreamWriter, this method performs a flush.

        This method uses OutputStreamWriter.

        Parameters:
        reader - the Reader to read from
        output - the OutputStream to write to
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        1.1
      • copy

        public static void copy(Reader reader,
                                OutputStream output,
                                Charset outputCharset)
                         throws IOException
        Copies chars from a Reader to bytes on an OutputStream using the specified character encoding, and calling flush.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Due to the implementation of OutputStreamWriter, this method performs a flush.

        This method uses OutputStreamWriter.

        Parameters:
        reader - the Reader to read from
        output - the OutputStream to write to
        outputCharset - the charset to use for the OutputStream, null means platform default
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        2.3
      • copy

        public static void copy(Reader reader,
                                OutputStream output,
                                String outputCharsetName)
                         throws IOException
        Copies chars from a Reader to bytes on an OutputStream using the specified character encoding, and calling flush.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Character encoding names can be found at IANA.

        Due to the implementation of OutputStreamWriter, this method performs a flush.

        This method uses OutputStreamWriter.

        Parameters:
        reader - the Reader to read from
        output - the OutputStream to write to
        outputCharsetName - the name of the requested charset for the OutputStream, null means platform default
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
        Since:
        1.1
      • copy

        public static int copy(Reader reader,
                               Writer writer)
                        throws IOException
        Copies chars from a Reader to a Writer.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Large streams (over 2GB) will return a chars copied value of -1 after the copy has completed since the correct number of chars cannot be returned as an int. For large streams use the copyLarge(Reader, Writer) method.

        Parameters:
        reader - the Reader to read.
        writer - the Writer to write.
        Returns:
        the number of characters copied, or -1 if > Integer.MAX_VALUE
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        1.1
      • copy

        public static long copy(URL url,
                                File file)
                         throws IOException
        Copies bytes from a URL to an OutputStream.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        The buffer size is given by DEFAULT_BUFFER_SIZE.

        Parameters:
        url - the URL to read.
        file - the OutputStream to write.
        Returns:
        the number of bytes copied.
        Throws:
        NullPointerException - if the URL is null.
        NullPointerException - if the OutputStream is null.
        IOException - if an I/O error occurs.
        Since:
        2.9.0
      • copy

        public static long copy(URL url,
                                OutputStream outputStream)
                         throws IOException
        Copies bytes from a URL to an OutputStream.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        The buffer size is given by DEFAULT_BUFFER_SIZE.

        Parameters:
        url - the URL to read.
        outputStream - the OutputStream to write.
        Returns:
        the number of bytes copied.
        Throws:
        NullPointerException - if the URL is null.
        NullPointerException - if the OutputStream is null.
        IOException - if an I/O error occurs.
        Since:
        2.9.0
      • copyLarge

        public static long copyLarge(InputStream inputStream,
                                     OutputStream outputStream)
                              throws IOException
        Copies bytes from a large (over 2GB) InputStream to an OutputStream.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        The buffer size is given by DEFAULT_BUFFER_SIZE.

        Parameters:
        inputStream - the InputStream to read.
        outputStream - the OutputStream to write.
        Returns:
        the number of bytes copied.
        Throws:
        NullPointerException - if the InputStream is null.
        NullPointerException - if the OutputStream is null.
        IOException - if an I/O error occurs.
        Since:
        1.3
      • copyLarge

        public static long copyLarge(InputStream inputStream,
                                     OutputStream outputStream,
                                     byte[] buffer)
                              throws IOException
        Copies bytes from a large (over 2GB) InputStream to an OutputStream.

        This method uses the provided buffer, so there is no need to use a BufferedInputStream.

        Parameters:
        inputStream - the InputStream to read.
        outputStream - the OutputStream to write.
        buffer - the buffer to use for the copy
        Returns:
        the number of bytes copied.
        Throws:
        NullPointerException - if the InputStream is null.
        NullPointerException - if the OutputStream is null.
        IOException - if an I/O error occurs.
        Since:
        2.2
      • copyLarge

        public static long copyLarge(InputStream input,
                                     OutputStream output,
                                     long inputOffset,
                                     long length)
                              throws IOException
        Copies some or all bytes from a large (over 2GB) InputStream to an OutputStream, optionally skipping input bytes.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.

        The buffer size is given by DEFAULT_BUFFER_SIZE.
        Parameters:
        input - the InputStream to read from
        output - the OutputStream to write to
        inputOffset - : number of bytes to skip from input before copying -ve values are ignored
        length - : number of bytes to copy. -ve means all
        Returns:
        the number of bytes copied
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        2.2
      • copyLarge

        public static long copyLarge(InputStream input,
                                     OutputStream output,
                                     long inputOffset,
                                     long length,
                                     byte[] buffer)
                              throws IOException
        Copies some or all bytes from a large (over 2GB) InputStream to an OutputStream, optionally skipping input bytes.

        This method uses the provided buffer, so there is no need to use a BufferedInputStream.

        Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.

        Parameters:
        input - the InputStream to read from
        output - the OutputStream to write to
        inputOffset - : number of bytes to skip from input before copying -ve values are ignored
        length - : number of bytes to copy. -ve means all
        buffer - the buffer to use for the copy
        Returns:
        the number of bytes copied
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        2.2
      • copyLarge

        public static long copyLarge(Reader reader,
                                     Writer writer)
                              throws IOException
        Copies chars from a large (over 2GB) Reader to a Writer.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        The buffer size is given by DEFAULT_BUFFER_SIZE.

        Parameters:
        reader - the Reader to source.
        writer - the Writer to target.
        Returns:
        the number of characters copied
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        1.3
      • copyLarge

        public static long copyLarge(Reader reader,
                                     Writer writer,
                                     char[] buffer)
                              throws IOException
        Copies chars from a large (over 2GB) Reader to a Writer.

        This method uses the provided buffer, so there is no need to use a BufferedReader.

        Parameters:
        reader - the Reader to source.
        writer - the Writer to target.
        buffer - the buffer to be used for the copy
        Returns:
        the number of characters copied
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        2.2
      • copyLarge

        public static long copyLarge(Reader reader,
                                     Writer writer,
                                     long inputOffset,
                                     long length)
                              throws IOException
        Copies some or all chars from a large (over 2GB) InputStream to an OutputStream, optionally skipping input chars.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        The buffer size is given by DEFAULT_BUFFER_SIZE.

        Parameters:
        reader - the Reader to read from
        writer - the Writer to write to
        inputOffset - : number of chars to skip from input before copying -ve values are ignored
        length - : number of chars to copy. -ve means all
        Returns:
        the number of chars copied
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        2.2
      • copyLarge

        public static long copyLarge(Reader reader,
                                     Writer writer,
                                     long inputOffset,
                                     long length,
                                     char[] buffer)
                              throws IOException
        Copies some or all chars from a large (over 2GB) InputStream to an OutputStream, optionally skipping input chars.

        This method uses the provided buffer, so there is no need to use a BufferedReader.

        Parameters:
        reader - the Reader to read from
        writer - the Writer to write to
        inputOffset - : number of chars to skip from input before copying -ve values are ignored
        length - : number of chars to copy. -ve means all
        buffer - the buffer to be used for the copy
        Returns:
        the number of chars copied
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        2.2
      • length

        public static int length(byte[] array)
        Returns the length of the given array in a null-safe manner.
        Parameters:
        array - an array or null
        Returns:
        the array length -- or 0 if the given array is null.
        Since:
        2.7
      • length

        public static int length(char[] array)
        Returns the length of the given array in a null-safe manner.
        Parameters:
        array - an array or null
        Returns:
        the array length -- or 0 if the given array is null.
        Since:
        2.7
      • length

        public static int length(CharSequence csq)
        Returns the length of the given CharSequence in a null-safe manner.
        Parameters:
        csq - a CharSequence or null
        Returns:
        the CharSequence length -- or 0 if the given CharSequence is null.
        Since:
        2.7
      • length

        public static int length(Object[] array)
        Returns the length of the given array in a null-safe manner.
        Parameters:
        array - an array or null
        Returns:
        the array length -- or 0 if the given array is null.
        Since:
        2.7
      • lineIterator

        public static LineIterator lineIterator(InputStream input,
                                                Charset charset)
        Returns an Iterator for the lines in an InputStream, using the character encoding specified (or default encoding if null).

        LineIterator holds a reference to the open InputStream specified here. When you have finished with the iterator you should close the stream to free internal resources. This can be done by closing the stream directly, or by calling LineIterator.close() or LineIterator.closeQuietly(LineIterator).

        The recommended usage pattern is:

         try {
           LineIterator it = IOUtils.lineIterator(stream, charset);
           while (it.hasNext()) {
             String line = it.nextLine();
             /// do something with line
           }
         } finally {
           IOUtils.closeQuietly(stream);
         }
         
        Parameters:
        input - the InputStream to read from, not null
        charset - the charset to use, null means platform default
        Returns:
        an Iterator of the lines in the reader, never null
        Throws:
        IllegalArgumentException - if the input is null
        Since:
        2.3
      • lineIterator

        public static LineIterator lineIterator(InputStream input,
                                                String charsetName)
        Returns an Iterator for the lines in an InputStream, using the character encoding specified (or default encoding if null).

        LineIterator holds a reference to the open InputStream specified here. When you have finished with the iterator you should close the stream to free internal resources. This can be done by closing the stream directly, or by calling LineIterator.close() or LineIterator.closeQuietly(LineIterator).

        The recommended usage pattern is:

         try {
           LineIterator it = IOUtils.lineIterator(stream, "UTF-8");
           while (it.hasNext()) {
             String line = it.nextLine();
             /// do something with line
           }
         } finally {
           IOUtils.closeQuietly(stream);
         }
         
        Parameters:
        input - the InputStream to read from, not null
        charsetName - the encoding to use, null means platform default
        Returns:
        an Iterator of the lines in the reader, never null
        Throws:
        IllegalArgumentException - if the input is null
        UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
        Since:
        1.2
      • lineIterator

        public static LineIterator lineIterator(Reader reader)
        Returns an Iterator for the lines in a Reader.

        LineIterator holds a reference to the open Reader specified here. When you have finished with the iterator you should close the reader to free internal resources. This can be done by closing the reader directly, or by calling LineIterator.close() or LineIterator.closeQuietly(LineIterator).

        The recommended usage pattern is:

         try {
           LineIterator it = IOUtils.lineIterator(reader);
           while (it.hasNext()) {
             String line = it.nextLine();
             /// do something with line
           }
         } finally {
           IOUtils.closeQuietly(reader);
         }
         
        Parameters:
        reader - the Reader to read from, not null
        Returns:
        an Iterator of the lines in the reader, never null
        Throws:
        IllegalArgumentException - if the reader is null
        Since:
        1.2
      • read

        public static int read(InputStream input,
                               byte[] buffer)
                        throws IOException
        Reads bytes from an input stream. This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for subclasses of InputStream.
        Parameters:
        input - where to read input from
        buffer - destination
        Returns:
        actual length read; may be less than requested if EOF was reached
        Throws:
        IOException - if a read error occurs
        Since:
        2.2
      • read

        public static int read(InputStream input,
                               byte[] buffer,
                               int offset,
                               int length)
                        throws IOException
        Reads bytes from an input stream. This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for subclasses of InputStream.
        Parameters:
        input - where to read input from
        buffer - destination
        offset - initial offset into buffer
        length - length to read, must be >= 0
        Returns:
        actual length read; may be less than requested if EOF was reached
        Throws:
        IOException - if a read error occurs
        Since:
        2.2
      • read

        public static int read(ReadableByteChannel input,
                               ByteBuffer buffer)
                        throws IOException
        Reads bytes from a ReadableByteChannel.

        This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for subclasses of ReadableByteChannel.

        Parameters:
        input - the byte channel to read
        buffer - byte buffer destination
        Returns:
        the actual length read; may be less than requested if EOF was reached
        Throws:
        IOException - if a read error occurs
        Since:
        2.5
      • read

        public static int read(Reader reader,
                               char[] buffer)
                        throws IOException
        Reads characters from an input character stream. This implementation guarantees that it will read as many characters as possible before giving up; this may not always be the case for subclasses of Reader.
        Parameters:
        reader - where to read input from
        buffer - destination
        Returns:
        actual length read; may be less than requested if EOF was reached
        Throws:
        IOException - if a read error occurs
        Since:
        2.2
      • read

        public static int read(Reader reader,
                               char[] buffer,
                               int offset,
                               int length)
                        throws IOException
        Reads characters from an input character stream. This implementation guarantees that it will read as many characters as possible before giving up; this may not always be the case for subclasses of Reader.
        Parameters:
        reader - where to read input from
        buffer - destination
        offset - initial offset into buffer
        length - length to read, must be >= 0
        Returns:
        actual length read; may be less than requested if EOF was reached
        Throws:
        IOException - if a read error occurs
        Since:
        2.2
      • readFully

        public static void readFully(InputStream input,
                                     byte[] buffer)
                              throws IOException
        Reads the requested number of bytes or fail if there are not enough left.

        This allows for the possibility that InputStream.read(byte[], int, int) may not read as many bytes as requested (most likely because of reaching EOF).

        Parameters:
        input - where to read input from
        buffer - destination
        Throws:
        IOException - if there is a problem reading the file
        IllegalArgumentException - if length is negative
        EOFException - if the number of bytes read was incorrect
        Since:
        2.2
      • readFully

        public static void readFully(InputStream input,
                                     byte[] buffer,
                                     int offset,
                                     int length)
                              throws IOException
        Reads the requested number of bytes or fail if there are not enough left.

        This allows for the possibility that InputStream.read(byte[], int, int) may not read as many bytes as requested (most likely because of reaching EOF).

        Parameters:
        input - where to read input from
        buffer - destination
        offset - initial offset into buffer
        length - length to read, must be >= 0
        Throws:
        IOException - if there is a problem reading the file
        IllegalArgumentException - if length is negative
        EOFException - if the number of bytes read was incorrect
        Since:
        2.2
      • readFully

        public static byte[] readFully(InputStream input,
                                       int length)
                                throws IOException
        Reads the requested number of bytes or fail if there are not enough left.

        This allows for the possibility that InputStream.read(byte[], int, int) may not read as many bytes as requested (most likely because of reaching EOF).

        Parameters:
        input - where to read input from
        length - length to read, must be >= 0
        Returns:
        the bytes read from input
        Throws:
        IOException - if there is a problem reading the file
        IllegalArgumentException - if length is negative
        EOFException - if the number of bytes read was incorrect
        Since:
        2.5
      • readFully

        public static void readFully(ReadableByteChannel input,
                                     ByteBuffer buffer)
                              throws IOException
        Reads the requested number of bytes or fail if there are not enough left.

        This allows for the possibility that ReadableByteChannel.read(ByteBuffer) may not read as many bytes as requested (most likely because of reaching EOF).

        Parameters:
        input - the byte channel to read
        buffer - byte buffer destination
        Throws:
        IOException - if there is a problem reading the file
        EOFException - if the number of bytes read was incorrect
        Since:
        2.5
      • readFully

        public static void readFully(Reader reader,
                                     char[] buffer)
                              throws IOException
        Reads the requested number of characters or fail if there are not enough left.

        This allows for the possibility that Reader.read(char[], int, int) may not read as many characters as requested (most likely because of reaching EOF).

        Parameters:
        reader - where to read input from
        buffer - destination
        Throws:
        IOException - if there is a problem reading the file
        IllegalArgumentException - if length is negative
        EOFException - if the number of characters read was incorrect
        Since:
        2.2
      • readFully

        public static void readFully(Reader reader,
                                     char[] buffer,
                                     int offset,
                                     int length)
                              throws IOException
        Reads the requested number of characters or fail if there are not enough left.

        This allows for the possibility that Reader.read(char[], int, int) may not read as many characters as requested (most likely because of reaching EOF).

        Parameters:
        reader - where to read input from
        buffer - destination
        offset - initial offset into buffer
        length - length to read, must be >= 0
        Throws:
        IOException - if there is a problem reading the file
        IllegalArgumentException - if length is negative
        EOFException - if the number of characters read was incorrect
        Since:
        2.2
      • readLines

        @Deprecated
        public static List<String> readLines(InputStream input)
                                                  throws IOException
        Deprecated.  2.5 use readLines(InputStream, Charset) instead
        Gets the contents of an InputStream as a list of Strings, one entry per line, using the default character encoding of the platform.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        input - the InputStream to read from, not null
        Returns:
        the list of Strings, never null
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        1.1
      • readLines

        public static List<String> readLines(InputStream input,
                                             Charset charset)
                                      throws IOException
        Gets the contents of an InputStream as a list of Strings, one entry per line, using the specified character encoding.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        input - the InputStream to read from, not null
        charset - the charset to use, null means platform default
        Returns:
        the list of Strings, never null
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        2.3
      • readLines

        public static List<String> readLines(InputStream input,
                                             String charsetName)
                                      throws IOException
        Gets the contents of an InputStream as a list of Strings, one entry per line, using the specified character encoding.

        Character encoding names can be found at IANA.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        input - the InputStream to read from, not null
        charsetName - the name of the requested charset, null means platform default
        Returns:
        the list of Strings, never null
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
        Since:
        1.1
      • readLines

        public static List<String> readLines(Reader reader)
                                      throws IOException
        Gets the contents of a Reader as a list of Strings, one entry per line.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Parameters:
        reader - the Reader to read from, not null
        Returns:
        the list of Strings, never null
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        1.1
      • resourceToByteArray

        public static byte[] resourceToByteArray(String name)
                                          throws IOException
        Gets the contents of a classpath resource as a byte array.

        It is expected the given name to be absolute. The behavior is not well-defined otherwise.

        Parameters:
        name - name of the desired resource
        Returns:
        the requested byte array
        Throws:
        IOException - if an I/O error occurs.
        Since:
        2.6
      • resourceToByteArray

        public static byte[] resourceToByteArray(String name,
                                                 ClassLoader classLoader)
                                          throws IOException
        Gets the contents of a classpath resource as a byte array.

        It is expected the given name to be absolute. The behavior is not well-defined otherwise.

        Parameters:
        name - name of the desired resource
        classLoader - the class loader that the resolution of the resource is delegated to
        Returns:
        the requested byte array
        Throws:
        IOException - if an I/O error occurs.
        Since:
        2.6
      • resourceToString

        public static String resourceToString(String name,
                                              Charset charset)
                                       throws IOException
        Gets the contents of a classpath resource as a String using the specified character encoding.

        It is expected the given name to be absolute. The behavior is not well-defined otherwise.

        Parameters:
        name - name of the desired resource
        charset - the charset to use, null means platform default
        Returns:
        the requested String
        Throws:
        IOException - if an I/O error occurs.
        Since:
        2.6
      • resourceToString

        public static String resourceToString(String name,
                                              Charset charset,
                                              ClassLoader classLoader)
                                       throws IOException
        Gets the contents of a classpath resource as a String using the specified character encoding.

        It is expected the given name to be absolute. The behavior is not well-defined otherwise.

        Parameters:
        name - name of the desired resource
        charset - the charset to use, null means platform default
        classLoader - the class loader that the resolution of the resource is delegated to
        Returns:
        the requested String
        Throws:
        IOException - if an I/O error occurs.
        Since:
        2.6
      • resourceToURL

        public static URL resourceToURL(String name)
                                 throws IOException
        Gets a URL pointing to the given classpath resource.

        It is expected the given name to be absolute. The behavior is not well-defined otherwise.

        Parameters:
        name - name of the desired resource
        Returns:
        the requested URL
        Throws:
        IOException - if an I/O error occurs.
        Since:
        2.6
      • resourceToURL

        public static URL resourceToURL(String name,
                                        ClassLoader classLoader)
                                 throws IOException
        Gets a URL pointing to the given classpath resource.

        It is expected the given name to be absolute. The behavior is not well-defined otherwise.

        Parameters:
        name - name of the desired resource
        classLoader - the class loader that the resolution of the resource is delegated to
        Returns:
        the requested URL
        Throws:
        IOException - if an I/O error occurs.
        Since:
        2.6
      • skip

        public static long skip(ReadableByteChannel input,
                                long toSkip)
                         throws IOException
        Skips bytes from a ReadableByteChannel. This implementation guarantees that it will read as many bytes as possible before giving up.
        Parameters:
        input - ReadableByteChannel to skip
        toSkip - number of bytes to skip.
        Returns:
        number of bytes actually skipped.
        Throws:
        IOException - if there is a problem reading the ReadableByteChannel
        IllegalArgumentException - if toSkip is negative
        Since:
        2.5
      • skip

        public static long skip(Reader reader,
                                long toSkip)
                         throws IOException
        Skips characters from an input character stream. This implementation guarantees that it will read as many characters as possible before giving up; this may not always be the case for skip() implementations in subclasses of Reader.

        Note that the implementation uses Reader.read(char[], int, int) rather than delegating to Reader.skip(long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.

        Parameters:
        reader - character stream to skip
        toSkip - number of characters to skip.
        Returns:
        number of characters actually skipped.
        Throws:
        IOException - if there is a problem reading the file
        IllegalArgumentException - if toSkip is negative
        Since:
        2.0
        See Also:
        Reader.skip(long), IO-203 - Add skipFully() method for InputStreams
      • skipFully

        public static void skipFully(InputStream input,
                                     long toSkip)
                              throws IOException
        Skips the requested number of bytes or fail if there are not enough left.

        This allows for the possibility that InputStream.skip(long) may not skip as many bytes as requested (most likely because of reaching EOF).

        Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.

        Parameters:
        input - stream to skip
        toSkip - the number of bytes to skip
        Throws:
        IOException - if there is a problem reading the file
        IllegalArgumentException - if toSkip is negative
        EOFException - if the number of bytes skipped was incorrect
        Since:
        2.0
        See Also:
        InputStream.skip(long)
      • skipFully

        public static void skipFully(ReadableByteChannel input,
                                     long toSkip)
                              throws IOException
        Skips the requested number of bytes or fail if there are not enough left.
        Parameters:
        input - ReadableByteChannel to skip
        toSkip - the number of bytes to skip
        Throws:
        IOException - if there is a problem reading the ReadableByteChannel
        IllegalArgumentException - if toSkip is negative
        EOFException - if the number of bytes skipped was incorrect
        Since:
        2.5
      • skipFully

        public static void skipFully(Reader reader,
                                     long toSkip)
                              throws IOException
        Skips the requested number of characters or fail if there are not enough left.

        This allows for the possibility that Reader.skip(long) may not skip as many characters as requested (most likely because of reaching EOF).

        Note that the implementation uses skip(Reader, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.

        Parameters:
        reader - stream to skip
        toSkip - the number of characters to skip
        Throws:
        IOException - if there is a problem reading the file
        IllegalArgumentException - if toSkip is negative
        EOFException - if the number of characters skipped was incorrect
        Since:
        2.0
        See Also:
        Reader.skip(long)
      • toBufferedInputStream

        public static InputStream toBufferedInputStream(InputStream input)
                                                 throws IOException
        Fetches entire contents of an InputStream and represent same data as result InputStream.

        This method is useful where,

        • Source InputStream is slow.
        • It has network resources associated, so we cannot keep it open for long time.
        • It has network timeout associated.
        It can be used in favor of toByteArray(InputStream), since it avoids unnecessary allocation and copy of byte[].
        This method buffers the input internally, so there is no need to use a BufferedInputStream.
        Parameters:
        input - Stream to be fully buffered.
        Returns:
        A fully buffered stream.
        Throws:
        IOException - if an I/O error occurs.
        Since:
        2.0
      • toBufferedInputStream

        public static InputStream toBufferedInputStream(InputStream input,
                                                        int size)
                                                 throws IOException
        Fetches entire contents of an InputStream and represent same data as result InputStream.

        This method is useful where,

        • Source InputStream is slow.
        • It has network resources associated, so we cannot keep it open for long time.
        • It has network timeout associated.
        It can be used in favor of toByteArray(InputStream), since it avoids unnecessary allocation and copy of byte[].
        This method buffers the input internally, so there is no need to use a BufferedInputStream.
        Parameters:
        input - Stream to be fully buffered.
        size - the initial buffer size
        Returns:
        A fully buffered stream.
        Throws:
        IOException - if an I/O error occurs.
        Since:
        2.5
      • toBufferedReader

        public static BufferedReader toBufferedReader(Reader reader)
        Returns the given reader if it is a BufferedReader, otherwise creates a BufferedReader from the given reader.
        Parameters:
        reader - the reader to wrap or return (not null)
        Returns:
        the given reader or a new BufferedReader for the given reader
        Throws:
        NullPointerException - if the input parameter is null
        Since:
        2.2
        See Also:
        buffer(Reader)
      • toBufferedReader

        public static BufferedReader toBufferedReader(Reader reader,
                                                      int size)
        Returns the given reader if it is a BufferedReader, otherwise creates a BufferedReader from the given reader.
        Parameters:
        reader - the reader to wrap or return (not null)
        size - the buffer size, if a new BufferedReader is created.
        Returns:
        the given reader or a new BufferedReader for the given reader
        Throws:
        NullPointerException - if the input parameter is null
        Since:
        2.5
        See Also:
        buffer(Reader)
      • toByteArray

        public static byte[] toByteArray(InputStream inputStream)
                                  throws IOException
        Gets the contents of an InputStream as a byte[].

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        inputStream - the InputStream to read.
        Returns:
        the requested byte array.
        Throws:
        NullPointerException - if the InputStream is null.
        IOException - if an I/O error occurs or reading more than Integer.MAX_VALUE occurs.
      • toByteArray

        public static byte[] toByteArray(InputStream input,
                                         int size)
                                  throws IOException
        Gets the contents of an InputStream as a byte[]. Use this method instead of toByteArray(InputStream) when InputStream size is known
        Parameters:
        input - the InputStream to read.
        size - the size of InputStream.
        Returns:
        the requested byte array.
        Throws:
        IOException - if an I/O error occurs or InputStream size differ from parameter size.
        IllegalArgumentException - if size is less than zero.
        Since:
        2.1
      • toByteArray

        public static byte[] toByteArray(InputStream input,
                                         long size)
                                  throws IOException
        Gets contents of an InputStream as a byte[]. Use this method instead of toByteArray(InputStream) when InputStream size is known. NOTE: the method checks that the length can safely be cast to an int without truncation before using toByteArray(java.io.InputStream, int) to read into the byte array. (Arrays can have no more than Integer.MAX_VALUE entries anyway)
        Parameters:
        input - the InputStream to read from
        size - the size of InputStream
        Returns:
        the requested byte array
        Throws:
        IOException - if an I/O error occurs or InputStream size differ from parameter size
        IllegalArgumentException - if size is less than zero or size is greater than Integer.MAX_VALUE
        Since:
        2.1
        See Also:
        toByteArray(java.io.InputStream, int)
      • toByteArray

        @Deprecated
        public static byte[] toByteArray(Reader reader)
                                              throws IOException
        Deprecated.  2.5 use toByteArray(Reader, Charset) instead
        Gets the contents of a Reader as a byte[] using the default character encoding of the platform.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Parameters:
        reader - the Reader to read from
        Returns:
        the requested byte array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
      • toByteArray

        public static byte[] toByteArray(Reader reader,
                                         Charset charset)
                                  throws IOException
        Gets the contents of a Reader as a byte[] using the specified character encoding.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Parameters:
        reader - the Reader to read from
        charset - the charset to use, null means platform default
        Returns:
        the requested byte array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        2.3
      • toByteArray

        public static byte[] toByteArray(Reader reader,
                                         String charsetName)
                                  throws IOException
        Gets the contents of a Reader as a byte[] using the specified character encoding.

        Character encoding names can be found at IANA.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Parameters:
        reader - the Reader to read from
        charsetName - the name of the requested charset, null means platform default
        Returns:
        the requested byte array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
        Since:
        1.1
      • toByteArray

        @Deprecated
        public static byte[] toByteArray(String input)
        Deprecated.  2.5 Use String.getBytes() instead
        Gets the contents of a String as a byte[] using the default character encoding of the platform.

        This is the same as String.getBytes().

        Parameters:
        input - the String to convert
        Returns:
        the requested byte array
        Throws:
        NullPointerException - if the input is null
      • toByteArray

        public static byte[] toByteArray(URI uri)
                                  throws IOException
        Gets the contents of a URI as a byte[].
        Parameters:
        uri - the URI to read
        Returns:
        the requested byte array
        Throws:
        NullPointerException - if the uri is null
        IOException - if an I/O exception occurs
        Since:
        2.4
      • toByteArray

        public static byte[] toByteArray(URL url)
                                  throws IOException
        Gets the contents of a URL as a byte[].
        Parameters:
        url - the URL to read
        Returns:
        the requested byte array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O exception occurs
        Since:
        2.4
      • toByteArray

        public static byte[] toByteArray(URLConnection urlConn)
                                  throws IOException
        Gets the contents of a URLConnection as a byte[].
        Parameters:
        urlConn - the URLConnection to read.
        Returns:
        the requested byte array.
        Throws:
        NullPointerException - if the urlConn is null.
        IOException - if an I/O exception occurs.
        Since:
        2.4
      • toCharArray

        @Deprecated
        public static char[] toCharArray(InputStream inputStream)
                                              throws IOException
        Deprecated.  2.5 use toCharArray(InputStream, Charset) instead
        Gets the contents of an InputStream as a character array using the default character encoding of the platform.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        inputStream - the InputStream to read from
        Returns:
        the requested character array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        1.1
      • toCharArray

        public static char[] toCharArray(InputStream inputStream,
                                         Charset charset)
                                  throws IOException
        Gets the contents of an InputStream as a character array using the specified character encoding.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        inputStream - the InputStream to read from
        charset - the charset to use, null means platform default
        Returns:
        the requested character array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        2.3
      • toCharArray

        public static char[] toCharArray(InputStream inputStream,
                                         String charsetName)
                                  throws IOException
        Gets the contents of an InputStream as a character array using the specified character encoding.

        Character encoding names can be found at IANA.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        inputStream - the InputStream to read from
        charsetName - the name of the requested charset, null means platform default
        Returns:
        the requested character array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
        Since:
        1.1
      • toCharArray

        public static char[] toCharArray(Reader reader)
                                  throws IOException
        Gets the contents of a Reader as a character array.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Parameters:
        reader - the Reader to read from
        Returns:
        the requested character array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        1.1
      • toInputStream

        @Deprecated
        public static InputStream toInputStream(CharSequence input)
        Deprecated.  2.5 use toInputStream(CharSequence, Charset) instead
        Converts the specified CharSequence to an input stream, encoded as bytes using the default character encoding of the platform.
        Parameters:
        input - the CharSequence to convert
        Returns:
        an input stream
        Since:
        2.0
      • toInputStream

        public static InputStream toInputStream(CharSequence input,
                                                Charset charset)
        Converts the specified CharSequence to an input stream, encoded as bytes using the specified character encoding.
        Parameters:
        input - the CharSequence to convert
        charset - the charset to use, null means platform default
        Returns:
        an input stream
        Since:
        2.3
      • toInputStream

        public static InputStream toInputStream(CharSequence input,
                                                String charsetName)
        Converts the specified CharSequence to an input stream, encoded as bytes using the specified character encoding.

        Character encoding names can be found at IANA.

        Parameters:
        input - the CharSequence to convert
        charsetName - the name of the requested charset, null means platform default
        Returns:
        an input stream
        Throws:
        UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
        Since:
        2.0
      • toInputStream

        @Deprecated
        public static InputStream toInputStream(String input)
        Deprecated.  2.5 use toInputStream(String, Charset) instead
        Converts the specified string to an input stream, encoded as bytes using the default character encoding of the platform.
        Parameters:
        input - the string to convert
        Returns:
        an input stream
        Since:
        1.1
      • toInputStream

        public static InputStream toInputStream(String input,
                                                Charset charset)
        Converts the specified string to an input stream, encoded as bytes using the specified character encoding.
        Parameters:
        input - the string to convert
        charset - the charset to use, null means platform default
        Returns:
        an input stream
        Since:
        2.3
      • toInputStream

        public static InputStream toInputStream(String input,
                                                String charsetName)
        Converts the specified string to an input stream, encoded as bytes using the specified character encoding.

        Character encoding names can be found at IANA.

        Parameters:
        input - the string to convert
        charsetName - the name of the requested charset, null means platform default
        Returns:
        an input stream
        Throws:
        UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
        Since:
        1.1
      • toString

        @Deprecated
        public static String toString(byte[] input)
        Deprecated.  2.5 Use String(byte[]) instead
        Gets the contents of a byte[] as a String using the default character encoding of the platform.
        Parameters:
        input - the byte array to read from
        Returns:
        the requested String
        Throws:
        NullPointerException - if the input is null
      • toString

        public static String toString(byte[] input,
                                      String charsetName)
        Gets the contents of a byte[] as a String using the specified character encoding.

        Character encoding names can be found at IANA.

        Parameters:
        input - the byte array to read from
        charsetName - the name of the requested charset, null means platform default
        Returns:
        the requested String
        Throws:
        NullPointerException - if the input is null
      • toString

        @Deprecated
        public static String toString(InputStream input)
                                           throws IOException
        Deprecated.  2.5 use toString(InputStream, Charset) instead
        Gets the contents of an InputStream as a String using the default character encoding of the platform.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        input - the InputStream to read from
        Returns:
        the requested String
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
      • toString

        public static String toString(InputStream input,
                                      Charset charset)
                               throws IOException
        Gets the contents of an InputStream as a String using the specified character encoding.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        input - the InputStream to read from
        charset - the charset to use, null means platform default
        Returns:
        the requested String
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        2.3
      • toString

        public static String toString(InputStream input,
                                      String charsetName)
                               throws IOException
        Gets the contents of an InputStream as a String using the specified character encoding.

        Character encoding names can be found at IANA.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        input - the InputStream to read from
        charsetName - the name of the requested charset, null means platform default
        Returns:
        the requested String
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
      • toString

        public static String toString(Reader reader)
                               throws IOException
        Gets the contents of a Reader as a String.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Parameters:
        reader - the Reader to read from
        Returns:
        the requested String
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
      • toString

        public static String toString(URI uri,
                                      Charset encoding)
                               throws IOException
        Gets the contents at the given URI.
        Parameters:
        uri - The URI source.
        encoding - The encoding name for the URL contents.
        Returns:
        The contents of the URL as a String.
        Throws:
        IOException - if an I/O exception occurs.
        Since:
        2.3.
      • toString

        public static String toString(URL url,
                                      Charset encoding)
                               throws IOException
        Gets the contents at the given URL.
        Parameters:
        url - The URL source.
        encoding - The encoding name for the URL contents.
        Returns:
        The contents of the URL as a String.
        Throws:
        IOException - if an I/O exception occurs.
        Since:
        2.3
      • write

        public static void write(byte[] data,
                                 OutputStream output)
                          throws IOException
        Writes bytes from a byte[] to an OutputStream.
        Parameters:
        data - the byte array to write, do not modify during output, null ignored
        output - the OutputStream to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        1.1
      • write

        public static void write(byte[] data,
                                 Writer writer,
                                 Charset charset)
                          throws IOException
        Writes bytes from a byte[] to chars on a Writer using the specified character encoding.

        This method uses String(byte[], String).

        Parameters:
        data - the byte array to write, do not modify during output, null ignored
        writer - the Writer to write to
        charset - the charset to use, null means platform default
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        2.3
      • write

        public static void write(byte[] data,
                                 Writer writer,
                                 String charsetName)
                          throws IOException
        Writes bytes from a byte[] to chars on a Writer using the specified character encoding.

        Character encoding names can be found at IANA.

        This method uses String(byte[], String).

        Parameters:
        data - the byte array to write, do not modify during output, null ignored
        writer - the Writer to write to
        charsetName - the name of the requested charset, null means platform default
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
        Since:
        1.1
      • write

        public static void write(char[] data,
                                 OutputStream output,
                                 Charset charset)
                          throws IOException
        Writes chars from a char[] to bytes on an OutputStream using the specified character encoding.

        This method uses String(char[]) and String.getBytes(String).

        Parameters:
        data - the char array to write, do not modify during output, null ignored
        output - the OutputStream to write to
        charset - the charset to use, null means platform default
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        2.3
      • write

        public static void write(char[] data,
                                 Writer writer)
                          throws IOException
        Writes chars from a char[] to a Writer
        Parameters:
        data - the char array to write, do not modify during output, null ignored
        writer - the Writer to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        1.1
      • write

        public static void write(CharSequence data,
                                 OutputStream output,
                                 Charset charset)
                          throws IOException
        Writes chars from a CharSequence to bytes on an OutputStream using the specified character encoding.

        This method uses String.getBytes(String).

        Parameters:
        data - the CharSequence to write, null ignored
        output - the OutputStream to write to
        charset - the charset to use, null means platform default
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        2.3
      • write

        public static void write(CharSequence data,
                                 Writer writer)
                          throws IOException
        Writes chars from a CharSequence to a Writer.
        Parameters:
        data - the CharSequence to write, null ignored
        writer - the Writer to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        2.0
      • write

        public static void write(String data,
                                 OutputStream output,
                                 Charset charset)
                          throws IOException
        Writes chars from a String to bytes on an OutputStream using the specified character encoding.

        This method uses String.getBytes(String).

        Parameters:
        data - the String to write, null ignored
        output - the OutputStream to write to
        charset - the charset to use, null means platform default
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        2.3
      • write

        public static void write(String data,
                                 Writer writer)
                          throws IOException
        Writes chars from a String to a Writer.
        Parameters:
        data - the String to write, null ignored
        writer - the Writer to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        1.1
      • write

        @Deprecated
        public static void write(StringBuffer data,
                                             OutputStream output)
                                      throws IOException
        Deprecated.  replaced by write(CharSequence, OutputStream)
        Writes chars from a StringBuffer to bytes on an OutputStream using the default character encoding of the platform.

        This method uses String.getBytes().

        Parameters:
        data - the StringBuffer to write, null ignored
        output - the OutputStream to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        1.1
      • write

        @Deprecated
        public static void write(StringBuffer data,
                                             Writer writer)
                                      throws IOException
        Deprecated.  replaced by write(CharSequence, Writer)
        Writes chars from a StringBuffer to a Writer.
        Parameters:
        data - the StringBuffer to write, null ignored
        writer - the Writer to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        1.1
      • writeChunked

        public static void writeChunked(byte[] data,
                                        OutputStream output)
                                 throws IOException
        Writes bytes from a byte[] to an OutputStream using chunked writes. This is intended for writing very large byte arrays which might otherwise cause excessive memory usage if the native code has to allocate a copy.
        Parameters:
        data - the byte array to write, do not modify during output, null ignored
        output - the OutputStream to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        2.5
      • writeChunked

        public static void writeChunked(char[] data,
                                        Writer writer)
                                 throws IOException
        Writes chars from a char[] to a Writer using chunked writes. This is intended for writing very large byte arrays which might otherwise cause excessive memory usage if the native code has to allocate a copy.
        Parameters:
        data - the char array to write, do not modify during output, null ignored
        writer - the Writer to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        2.5
      • writeLines

        @Deprecated
        public static void writeLines(Collection<?> lines,
                                                  String lineEnding,
                                                  OutputStream output)
                                           throws IOException
        Writes the toString() value of each item in a collection to an OutputStream line by line, using the default character encoding of the platform and the specified line ending.
        Parameters:
        lines - the lines to write, null entries produce blank lines
        lineEnding - the line separator to use, null is system default
        output - the OutputStream to write to, not null, not closed
        Throws:
        NullPointerException - if the output is null
        IOException - if an I/O error occurs
        Since:
        1.1
      • writeLines

        public static void writeLines(Collection<?> lines,
                                      String lineEnding,
                                      OutputStream output,
                                      Charset charset)
                               throws IOException
        Writes the toString() value of each item in a collection to an OutputStream line by line, using the specified character encoding and the specified line ending.
        Parameters:
        lines - the lines to write, null entries produce blank lines
        lineEnding - the line separator to use, null is system default
        output - the OutputStream to write to, not null, not closed
        charset - the charset to use, null means platform default
        Throws:
        NullPointerException - if the output is null
        IOException - if an I/O error occurs
        Since:
        2.3
      • writeLines

        public static void writeLines(Collection<?> lines,
                                      String lineEnding,
                                      OutputStream output,
                                      String charsetName)
                               throws IOException
        Writes the toString() value of each item in a collection to an OutputStream line by line, using the specified character encoding and the specified line ending.

        Character encoding names can be found at IANA.

        Parameters:
        lines - the lines to write, null entries produce blank lines
        lineEnding - the line separator to use, null is system default
        output - the OutputStream to write to, not null, not closed
        charsetName - the name of the requested charset, null means platform default
        Throws:
        NullPointerException - if the output is null
        IOException - if an I/O error occurs
        UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported.
        Since:
        1.1
      • writeLines

        public static void writeLines(Collection<?> lines,
                                      String lineEnding,
                                      Writer writer)
                               throws IOException
        Writes the toString() value of each item in a collection to a Writer line by line, using the specified line ending.
        Parameters:
        lines - the lines to write, null entries produce blank lines
        lineEnding - the line separator to use, null is system default
        writer - the Writer to write to, not null, not closed
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        1.1
      • writer

        public static Writer writer(Appendable appendable)
        Returns the given Appendable if it is already a Writer, otherwise creates a Writer wrapper around the given Appendable.
        Parameters:
        appendable - the Appendable to wrap or return (not null)
        Returns:
        the given Appendable or a Writer wrapper around the given Appendable
        Throws:
        NullPointerException - if the input parameter is null
        Since:
        2.7

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