org.apache.commons.io.input

Class BoundedReader

  • All Implemented Interfaces:
    Closeable, AutoCloseable, Readable

    public class BoundedReader
    extends Reader
    A reader that imposes a limit to the number of characters that can be read from an underlying reader, returning EOF when this limit is reached, regardless of state of underlying reader.

    One use case is to avoid overrunning the readAheadLimit supplied to Reader.mark(int), since reading too many characters removes the ability to do a successful reset.

    Since:
    2.5
    • Constructor Detail

      • BoundedReader

        public BoundedReader(Reader target,
                             int maxCharsFromTargetReader)
        Constructs a bounded reader
        Parameters:
        target - The target stream that will be used
        maxCharsFromTargetReader - The maximum number of characters that can be read from target
    • Method Detail

      • reset

        public void reset()
                   throws IOException
        Resets the target to the latest mark,
        Overrides:
        reset in class  Reader
        Throws:
        IOException - If an I/O error occurs while calling the underlying reader's reset method
        See Also:
        Reader.reset()
      • mark

        public void mark(int readAheadLimit)
                  throws IOException
        marks the target stream
        Overrides:
        mark in class  Reader
        Parameters:
        readAheadLimit - The number of characters that can be read while still retaining the ability to do #reset(). Note that this parameter is not validated with respect to maxCharsFromTargetReader. There is no way to pass past maxCharsFromTargetReader, even if this value is greater.
        Throws:
        IOException - If an I/O error occurs while calling the underlying reader's mark method
        See Also:
        Reader.mark(int)
      • read

        public int read()
                 throws IOException
        Reads a single character
        Overrides:
        read in class  Reader
        Returns:
        -1 on EOF or the character read
        Throws:
        IOException - If an I/O error occurs while calling the underlying reader's read method
        See Also:
        Reader.read()
      • read

        public int read(char[] cbuf,
                        int off,
                        int len)
                 throws IOException
        Reads into an array
        Specified by:
        read in class  Reader
        Parameters:
        cbuf - The buffer to fill
        off - The offset
        len - The number of chars to read
        Returns:
        the number of chars read
        Throws:
        IOException - If an I/O error occurs while calling the underlying reader's read method
        See Also:
        Reader.read(char[], int, int)

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