com.oreilly.servlet.multipart

Class BufferedServletInputStream

java.lang.Object

java.io.InputStream

javax.servlet.ServletInputStream

com.oreilly.servlet.multipart.BufferedServletInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class BufferedServletInputStream
extends javax.servlet.ServletInputStream

A BufferedServletInputStream wraps a ServletInputStream in order to provide input buffering and to avoid calling the the readLine method of the wrapped ServletInputStream.

This is necessary because some servlet containers rely on the default implementation of the readLine method provided by the Servlet API classes, which is very slow. Tomcat 3.2, Tomcat 3.1, the JSWDK 1.0 web server and the JSDK2.1 web server are all known to need this class for performance reasons.

Also, it may be used to work around a bug in the Servlet API 2.0 implementation of readLine which contains a bug that causes ArrayIndexOutOfBoundsExceptions under certain conditions. Apache JServ is known to suffer from this bug.

Constructor Summary

Constructors

Constructor and Description
BufferedServletInputStream(javax.servlet.ServletInputStream in) Creates a BufferedServletInputStream that wraps the provided ServletInputStream.

Method Summary

Modifier and Type	Method and Description
int	read() Implement buffering on top of the read method of the wrapped ServletInputStream.
int	read(byte[] b, int off, int len) Implement buffering on top of the read method of the wrapped ServletInputStream.
int	readLine(byte[] b, int off, int len) Implement buffering on top of the readLine method of the wrapped ServletInputStream.

Methods inherited from class java.io.InputStream

available, close, mark, markSupported, read, reset, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

BufferedServletInputStream

public BufferedServletInputStream(javax.servlet.ServletInputStream in)

Creates a BufferedServletInputStream that wraps the provided ServletInputStream.

Parameters:

in - a servlet input stream.

Method Detail

readLine

public int readLine(byte[] b,
                    int off,
                    int len)
             throws java.io.IOException

Implement buffering on top of the readLine method of the wrapped ServletInputStream.

Overrides:

readLine in class javax.servlet.ServletInputStream

Parameters:

b - an array of bytes into which data is read.

off - an integer specifying the character at which this method begins reading.

len - an integer specifying the maximum number of bytes to read.

Returns:

an integer specifying the actual number of bytes read, or -1 if the end of the stream is reached.

Throws:

java.io.IOException - if an I/O error occurs.

read

public int read()
         throws java.io.IOException

Implement buffering on top of the read method of the wrapped ServletInputStream.

Specified by:

read in class java.io.InputStream

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.

read

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

Implement buffering on top of the read method of the wrapped ServletInputStream.

Overrides:

read in class java.io.InputStream

Parameters:

b - the buffer into which the data is read.

off - the start offset of the data.

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.io.IOException - if an I/O error occurs.