org.apache.commons.httpclient

Class ContentLengthInputStream


public class ContentLengthInputStream
extends InputStream

Cuts the wrapped InputStream off after a specified number of bytes.

Implementation note: Choices abound. One approach would pass through the InputStream.mark and InputStream.reset calls to the underlying stream. That's tricky, though, because you then have to start duplicating the work of keeping track of how much a reset rewinds. Further, you have to watch out for the "readLimit", and since the semantics for the readLimit leave room for differing implementations, you might get into a lot of trouble.

Alternatively, you could make this class extend java.io.BufferedInputStream and then use the protected members of that class to avoid duplicated effort. That solution has the side effect of adding yet another possible layer of buffering.

Then, there is the simple choice, which this takes - simply don't support InputStream.mark and InputStream.reset. That choice has the added benefit of keeping this class very simple.

Authors:
Ortwin Glueck
Eric Johnson
Mike Bowler
Since:
2.0

Constructor Summary

ContentLengthInputStream(InputStream in, int contentLength)
Deprecated. use ContentLengthInputStream(InputStream,long) Creates a new length limited stream
ContentLengthInputStream(InputStream in, long contentLength)
Creates a new length limited stream

Method Summary

void
close()
Reads until the end of the known length of content.
int
read()
Read the next byte from the stream
int
read(byte[] b)
Read more bytes from the stream.
int
read(byte[] b, int off, int len)
Does standard InputStream.read(byte[], int, int) behavior, but also notifies the watcher when the contents have been consumed.
long
skip(long n)
Skips and discards a number of bytes from the input stream.

Constructor Details

ContentLengthInputStream

public ContentLengthInputStream(InputStream in,
                                int contentLength)

Deprecated. use ContentLengthInputStream(InputStream,long) Creates a new length limited stream

Parameters:
in - The stream to wrap
contentLength - The maximum number of bytes that can be read from the stream. Subsequent read operations will return -1.

ContentLengthInputStream

public ContentLengthInputStream(InputStream in,
                                long contentLength)
Creates a new length limited stream
Parameters:
in - The stream to wrap
contentLength - The maximum number of bytes that can be read from the stream. Subsequent read operations will return -1.
Since:
3.0

Method Details

close

public void close()
            throws IOException
Reads until the end of the known length of content.

Does not close the underlying socket input, but instead leaves it primed to parse the next response.


read

public int read()
            throws IOException
Read the next byte from the stream
Returns:
The next byte or -1 if the end of stream has been reached.
See Also:
java.io.InputStream.read()

read

public int read(byte[] b)
            throws IOException
Read more bytes from the stream.
Parameters:
b - The byte array to put the new data in.
Returns:
The number of bytes read into the buffer.
See Also:
java.io.InputStream.read(byte[])

read

public int read(byte[] b,
                int off,
                int len)
            throws java.io.IOException
Does standard InputStream.read(byte[], int, int) behavior, but also notifies the watcher when the contents have been consumed.
Parameters:
b - The byte array to fill.
off - Start filling at this position.
len - The number of bytes to attempt to read.
Returns:
The number of bytes read, or -1 if the end of content has been reached.

skip

public long skip(long n)
            throws IOException
Skips and discards a number of bytes from the input stream.
Parameters:
n - The number of bytes to skip.
Returns:
The actual number of bytes skipped. <= 0 if no bytes are skipped.
See Also:
InputStream.skip(long)

Copyright (c) 1999-2005 - Apache Software Foundation