org.apache.commons.fileupload.util
Class LimitedInputStream

java.lang.Object
  extended by java.io.InputStream
      extended by java.io.FilterInputStream
          extended by org.apache.commons.fileupload.util.LimitedInputStream
All Implemented Interfaces:
java.io.Closeable

public abstract class LimitedInputStream
extends java.io.FilterInputStream
implements Closeable

An input stream, which limits its data size. This stream is used, if the content length is unknown.


Field Summary
private  boolean closed
          Whether this stream is already closed.
private  long count
          The current number of bytes.
private  long sizeMax
          The maximum size of an item, in bytes.
 
Fields inherited from class java.io.FilterInputStream
in
 
Constructor Summary
LimitedInputStream(java.io.InputStream pIn, long pSizeMax)
          Creates a new instance.
 
Method Summary
private  void checkLimit()
          Called to check, whether the input streams limit is reached.
 void close()
          Closes this input stream and releases any system resources associated with the stream.
 boolean isClosed()
          Returns, whether this stream is already closed.
protected abstract  void raiseError(long pSizeMax, long pCount)
          Called to indicate, that the input streams limit has been exceeded.
 int read()
          Reads the next byte of data from this input stream.
 int read(byte[] b, int off, int len)
          Reads up to len bytes of data from this input stream into an array of bytes.
 
Methods inherited from class java.io.FilterInputStream
available, mark, markSupported, read, reset, skip
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

sizeMax

private long sizeMax
The maximum size of an item, in bytes.


count

private long count
The current number of bytes.


closed

private boolean closed
Whether this stream is already closed.

Constructor Detail

LimitedInputStream

public LimitedInputStream(java.io.InputStream pIn,
                          long pSizeMax)
Creates a new instance.

Parameters:
pIn - The input stream, which shall be limited.
pSizeMax - The limit; no more than this number of bytes shall be returned by the source stream.
Method Detail

raiseError

protected abstract void raiseError(long pSizeMax,
                                   long pCount)
                            throws java.io.IOException
Called to indicate, that the input streams limit has been exceeded.

Parameters:
pSizeMax - The input streams limit, in bytes.
pCount - The actual number of bytes.
Throws:
java.io.IOException - The called method is expected to raise an IOException.

checkLimit

private void checkLimit()
                 throws java.io.IOException
Called to check, whether the input streams limit is reached.

Throws:
java.io.IOException - The given limit is exceeded.

read

public int read()
         throws java.io.IOException
Reads the next byte of data from this input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

This method simply performs in.read() and returns the result.

Overrides:
read in class java.io.FilterInputStream
Returns:
the next byte of data, or -1 if the end of the stream is reached.
Throws:
java.io.IOException - if an I/O error occurs.
See Also:
FilterInputStream.in

read

public int read(byte[] b,
                int off,
                int len)
         throws java.io.IOException
Reads up to len bytes of data from this input stream into an array of bytes. If len is not zero, the method blocks until some input is available; otherwise, no bytes are read and 0 is returned.

This method simply performs in.read(b, off, len) and returns the result.

Overrides:
read in class java.io.FilterInputStream
Parameters:
b - the buffer into which the data is read.
off - The start offset in the destination array b.
len - the maximum number of bytes read.
Returns:
the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.
Throws:
java.lang.NullPointerException - If b is null.
java.lang.IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than b.length - off
java.io.IOException - if an I/O error occurs.
See Also:
FilterInputStream.in

isClosed

public boolean isClosed()
                 throws java.io.IOException
Returns, whether this stream is already closed.

Returns:
True, if the stream is closed, otherwise false.
Throws:
java.io.IOException - An I/O error occurred.

close

public void close()
           throws java.io.IOException
Closes this input stream and releases any system resources associated with the stream. This method simply performs in.close().

Specified by:
close in interface java.io.Closeable
Overrides:
close in class java.io.FilterInputStream
Throws:
java.io.IOException - if an I/O error occurs.
See Also:
FilterInputStream.in