org.apache.commons.io.input
Class AutoCloseInputStream

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

All Implemented Interfaces:

Closeable

public class AutoCloseInputStream
extends ProxyInputStream

Proxy stream that closes and discards the underlying stream as soon as the end of input has been reached or when the stream is explicitly closed. Not even a reference to the underlying stream is kept after it has been closed, so any allocated in-memory buffers can be freed even if the client application still keeps a reference to the proxy stream.

This class is typically used to release any resources related to an open stream as soon as possible even if the client application (by not explicitly closing the stream when no longer needed) or the underlying stream (by not releasing resources once the last byte has been read) do not do that.

Since:

Commons IO 1.4

Version:

$Id: AutoCloseInputStream.java 610010 2008-01-08 14:50:59Z niallp $

Field Summary

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

AutoCloseInputStream(InputStream in)
Creates an automatically closing proxy for the given input stream.

Method Summary

void	close() Closes the underlying input stream and replaces the reference to it with a ClosedInputStream instance.
protected void	finalize() Ensures that the stream is closed before it gets garbage-collected.
int	read() Reads and returns a single byte from the underlying input stream.
int	read(byte[] b) Reads and returns bytes from the underlying input stream to the given buffer.
int	read(byte[] b, int off, int len) Reads and returns bytes from the underlying input stream to the given buffer.

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

available, mark, markSupported, reset, skip

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AutoCloseInputStream

public AutoCloseInputStream(InputStream in)

Creates an automatically closing proxy for the given input stream.

Parameters:

in - underlying input stream

Method Detail

close

public void close()
           throws IOException

Closes the underlying input stream and replaces the reference to it with a ClosedInputStream instance.

This method is automatically called by the read methods when the end of input has been reached.

Note that it is safe to call this method any number of times. The original underlying input stream is closed and discarded only once when this method is first called.

Specified by:

close in interface Closeable

Overrides:

close in class ProxyInputStream

Throws:

IOException - if the underlying input stream can not be closed

read

public int read()
         throws IOException

Reads and returns a single byte from the underlying input stream. If the underlying stream returns -1, the close() method is called to automatically close and discard the stream.

Overrides:

read in class ProxyInputStream

Returns:

next byte in the stream, or -1 if no more bytes are available

Throws:

IOException - if the stream could not be read or closed

read

public int read(byte[] b)
         throws IOException

Reads and returns bytes from the underlying input stream to the given buffer. If the underlying stream returns -1, the close() method i called to automatically close and discard the stream.

Overrides:

read in class ProxyInputStream

Parameters:

b - buffer to which bytes from the stream are written

Returns:

number of bytes read, or -1 if no more bytes are available

Throws:

IOException - if the stream could not be read or closed

read

public int read(byte[] b,
                int off,
                int len)
         throws IOException

Reads and returns bytes from the underlying input stream to the given buffer. If the underlying stream returns -1, the close() method i called to automatically close and discard the stream.

Overrides:

read in class ProxyInputStream

Parameters:

b - buffer to which bytes from the stream are written

off - start offset within the buffer

len - maximum number of bytes to read

Returns:

number of bytes read, or -1 if no more bytes are available

Throws:

IOException - if the stream could not be read or closed

finalize

protected void finalize()
                 throws Throwable

Ensures that the stream is closed before it gets garbage-collected. As mentioned in close(), this is a no-op if the stream has already been closed.

Overrides:

finalize in class Object

Throws:

Throwable - if an error occurs