public class

ContentLengthInputStream

extends InputStream
java.lang.Object
   ↳ java.io.InputStream
     ↳ org.apache.http.impl.io.ContentLengthInputStream

Class Overview

Stream that cuts off after a specified number of bytes. Note that this class NEVER closes the underlying stream, even when close gets called. Instead, it will read until the "end" of its chunking on close, which allows for the seamless execution of subsequent HTTP 1.1 requests, while not requiring the client to remember to read the entire contents of the response.

Implementation note: Choices abound. One approach would pass through the mark(int) and 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 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 mark(int) and reset(). That choice has the added benefit of keeping this class very simple.

Summary

Public Constructors
ContentLengthInputStream(SessionInputBuffer in, long contentLength)
Creates a new length limited stream
Public Methods
void close()

Reads until the end of the known length of content.

int read(byte[] b, int off, int len)
Does standard read(byte[], int, int) behavior, but also notifies the watcher when the contents have been consumed.
int read(byte[] b)
Read more bytes from the stream.
int read()
Read the next byte from the stream
long skip(long n)
Skips and discards a number of bytes from the input stream.
[Expand]
Inherited Methods
From class java.io.InputStream
From class java.lang.Object
From interface java.io.Closeable

Public Constructors

public ContentLengthInputStream (SessionInputBuffer in, long contentLength)

Creates a new length limited stream

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

Public Methods

public void close ()

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.

Throws
IOException If an IO problem occurs.

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

Does standard 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.
Throws
IOException Should an error occur on the wrapped stream.

public int read (byte[] b)

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.
Throws
IOException If an IO problem occurs
See Also

public int read ()

Read the next byte from the stream

Returns
  • The next byte or -1 if the end of stream has been reached.
Throws
IOException If an IO problem occurs
See Also

public long skip (long n)

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.
Throws
IOException If an error occurs while skipping bytes.
See Also