Javadoc: ObservableInputStream (Apache Commons IO 2.11.0 API)

java.lang.Object
- java.io.InputStream
- - java.io.FilterInputStream
  - - org.apache.commons.io.input.ProxyInputStream
    - - org.apache.commons.io.input.ObservableInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

MessageDigestCalculatingInputStream
```
public class ObservableInputStream
extends ProxyInputStream
```
The ObservableInputStream allows, that an InputStream may be consumed by other receivers, apart from the thread, which is reading it. The other consumers are implemented as instances of ObservableInputStream.Observer.
A typical application may be the generation of a MessageDigest on the fly.

Note: The ObservableInputStream is not thread safe, as instances of InputStream usually aren't. If you must access the stream from multiple threads, then synchronization, locking, or a similar means must be used.

See Also:

MessageDigestCalculatingInputStream

Nested Class Summary

Nested Classes

Modifier and Type Class and Description

static class ObservableInputStream.Observer
Abstracts observer callback for ObservableInputStreams.

Nested Classes
Modifier and Type	Class and Description
`static class`	`ObservableInputStream.Observer` Abstracts observer callback for `ObservableInputStream`s.

Field Summary
- Fields inherited from class java.io.FilterInputStream
  in

Constructor Summary

Constructors
Constructor and Description
`ObservableInputStream(InputStream inputStream)` Creates a new ObservableInputStream for the given InputStream.
`ObservableInputStream(InputStream inputStream, ObservableInputStream.Observer... observers)` Creates a new ObservableInputStream for the given InputStream.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`add(ObservableInputStream.Observer observer)` Adds an Observer.
`void`	`close()` Invokes the delegate's `close()` method.
`void`	`consume()` Reads all data from the underlying `InputStream`, while notifying the observers.
`List<ObservableInputStream.Observer>`	`getObservers()` Gets all currently registered observers.
`protected void`	`noteClosed()` Notifies the observers by invoking `ObservableInputStream.Observer.finished()`.
`protected void`	`noteDataByte(int value)` Notifies the observers by invoking `ObservableInputStream.Observer.data(int)` with the given arguments.
`protected void`	`noteDataBytes(byte[] buffer, int offset, int length)` Notifies the observers by invoking `ObservableInputStream.Observer.data(byte[],int,int)` with the given arguments.
`protected void`	`noteError(IOException exception)` Notifies the observers by invoking `ObservableInputStream.Observer.error(IOException)` with the given argument.
`protected void`	`noteFinished()` Notifies the observers by invoking `ObservableInputStream.Observer.finished()`.
`int`	`read()` Invokes the delegate's `read()` method.
`int`	`read(byte[] buffer)` Invokes the delegate's `read(byte[])` method.
`int`	`read(byte[] buffer, int offset, int length)` Invokes the delegate's `read(byte[], int, int)` method.
`void`	`remove(ObservableInputStream.Observer observer)` Removes an Observer.
`void`	`removeAllObservers()` Removes all Observers.

Methods inherited from class org.apache.commons.io.input.ProxyInputStream
afterRead, available, beforeRead, handleIOException, mark, markSupported, reset, skip

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ObservableInputStream
```
public ObservableInputStream(InputStream inputStream)
```
    Creates a new ObservableInputStream for the given InputStream.
    
    Parameters:
    
    inputStream - the input stream to observe.
  - ObservableInputStream
```
public ObservableInputStream(InputStream inputStream,
                             ObservableInputStream.Observer... observers)
```
    Creates a new ObservableInputStream for the given InputStream.
    
    Parameters:
    
    inputStream - the input stream to observe.
    
    observers - List of observer callbacks.
    
    Since:
    
    2.9.0
- Method Detail
  - add
```
public void add(ObservableInputStream.Observer observer)
```
    Adds an Observer.
    
    Parameters:
    
    observer - the observer to add.
  - close
```
public void close()
           throws IOException
```
    Description copied from class: ProxyInputStream
    
    Invokes the delegate's close() method.
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
    
    Overrides:
    
    close in class ProxyInputStream
    
    Throws:
    
    IOException - if an I/O error occurs.
  - consume
```
public void consume()
             throws IOException
```
    Reads all data from the underlying InputStream, while notifying the observers.
    
    Throws:
    
    IOException - The underlying InputStream, or either of the observers has thrown an exception.
  - getObservers
```
public List<ObservableInputStream.Observer> getObservers()
```
    Gets all currently registered observers.
    
    Returns:
    
    a list of the currently registered observers.
    
    Since:
    
    2.9.0
  - noteClosed
```
protected void noteClosed()
                   throws IOException
```
    Notifies the observers by invoking ObservableInputStream.Observer.finished().
    
    Throws:
    
    IOException - Some observer has thrown an exception, which is being passed down.
  - noteDataByte
```
protected void noteDataByte(int value)
                     throws IOException
```
    Notifies the observers by invoking ObservableInputStream.Observer.data(int) with the given arguments.
    
    Parameters:
    
    value - Passed to the observers.
    
    Throws:
    
    IOException - Some observer has thrown an exception, which is being passed down.
  - noteDataBytes
```
protected void noteDataBytes(byte[] buffer,
                             int offset,
                             int length)
                      throws IOException
```
    Notifies the observers by invoking ObservableInputStream.Observer.data(byte[],int,int) with the given arguments.
    
    Parameters:
    
    buffer - Passed to the observers.
    
    offset - Passed to the observers.
    
    length - Passed to the observers.
    
    Throws:
    
    IOException - Some observer has thrown an exception, which is being passed down.
  - noteError
```
protected void noteError(IOException exception)
                  throws IOException
```
    Notifies the observers by invoking ObservableInputStream.Observer.error(IOException) with the given argument.
    
    Parameters:
    
    exception - Passed to the observers.
    
    Throws:
    
    IOException - Some observer has thrown an exception, which is being passed down. This may be the same exception, which has been passed as an argument.
  - noteFinished
```
protected void noteFinished()
                     throws IOException
```
    Notifies the observers by invoking ObservableInputStream.Observer.finished().
    
    Throws:
    
    IOException - Some observer has thrown an exception, which is being passed down.
  - read
```
public int read()
         throws IOException
```
    Description copied from class: ProxyInputStream
    
    Invokes the delegate's read() method.
    
    Overrides:
    
    read in class ProxyInputStream
    
    Returns:
    
    the byte read or -1 if the end of stream
    
    Throws:
    
    IOException - if an I/O error occurs.
  - read
```
public int read(byte[] buffer)
         throws IOException
```
    Description copied from class: ProxyInputStream
    
    Invokes the delegate's read(byte[]) method.
    
    Overrides:
    
    read in class ProxyInputStream
    
    Parameters:
    
    buffer - the buffer to read the bytes into
    
    Returns:
    
    the number of bytes read or EOF if the end of stream
    
    Throws:
    
    IOException - if an I/O error occurs.
  - read
```
public int read(byte[] buffer,
                int offset,
                int length)
         throws IOException
```
    Description copied from class: ProxyInputStream
    
    Invokes the delegate's read(byte[], int, int) method.
    
    Overrides:
    
    read in class ProxyInputStream
    
    Parameters:
    
    buffer - the buffer to read the bytes into
    
    offset - The start offset
    
    length - The number of bytes to read
    
    Returns:
    
    the number of bytes read or -1 if the end of stream
    
    Throws:
    
    IOException - if an I/O error occurs.
  - remove
```
public void remove(ObservableInputStream.Observer observer)
```
    Removes an Observer.
    
    Parameters:
    
    observer - the observer to remove
  - removeAllObservers
```
public void removeAllObservers()
```
    Removes all Observers.

Group Id	commons-io
Artifact Id	commons-io
Version	2.11.0
Last Release	2.11.0
Navigation	Index Tree Use Deprecated Help
Last Updated	2021-07-10

Class ObservableInputStream

Nested Class Summary

Field Summary

Fields inherited from class java.io.FilterInputStream

Constructor Summary

Method Summary

Methods inherited from class org.apache.commons.io.input.ProxyInputStream

Methods inherited from class java.lang.Object

Constructor Detail

ObservableInputStream

ObservableInputStream

Method Detail

add

close

consume

getObservers

noteClosed

noteDataByte

noteDataBytes

noteError

noteFinished

read

read

read

remove

removeAllObservers