com.oreilly.servlet.multipart
Class PartInputStream

java.lang.Object
  java.io.InputStream
      java.io.FilterInputStream
          com.oreilly.servlet.multipart.PartInputStream

All Implemented Interfaces:

java.io.Closeable

public class PartInputStream
extends java.io.FilterInputStream

A PartInputStream filters a ServletInputStream, providing access to a single MIME part contained with in which ends with the boundary specified. It uses buffering to provide maximum performance.

Note the readLine method of ServletInputStream has the annoying habit of adding a \r\n to the end of the last line. Since we want a byte-for-byte transfer, we have to cut those chars. This means that we must always maintain at least 2 characters in our buffer to allow us to trim when necessary.

Version:

1.4, 2002/11/01, fix for "unexpected end of part" caused by boundary newlines split across buffers, 1.3, 2001/05/21, fix to handle boundaries crossing 64K mark, 1.2, 2001/02/07, added read(byte[]) implementation for safety, 1.1, 2000/11/26, fixed available() to never return negative, 1.0, 2000/10/27, initial revision

Author:

Geoff Soutter, Jason Hunter

Method Summary

int	available() Returns the number of bytes that can be read from this input stream without blocking.
void	close() Closes this input stream and releases any system resources associated with the stream.
int	read() See the general contract of the read method of InputStream.
int	read(byte[] b) See the general contract of the read method of InputStream.
int	read(byte[] b, int off, int len) See the general contract of the read method of InputStream.

Methods inherited from class java.io.FilterInputStream

mark, markSupported, reset, skip

Methods inherited from class java.lang.Object

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

Method Detail

read

public int read()
         throws java.io.IOException

See the general contract of the read method of InputStream.

Returns -1 (end of file) when the MIME boundary of this part is encountered.

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.

read

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

See the general contract of the read method of InputStream.

Returns -1 (end of file) when the MIME boundary of this part is encountered.

Overrides:

read in class java.io.FilterInputStream

Parameters:

b - the buffer into which the data is 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.

read

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

See the general contract of the read method of InputStream.

Returns -1 (end of file) when the MIME boundary of this part is encountered.

Overrides:

read in class java.io.FilterInputStream

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.

available

public int available()
              throws java.io.IOException

Returns the number of bytes that can be read from this input stream without blocking. This is a standard InputStream idiom to deal with buffering gracefully, and is not same as the length of the part arriving in this stream.

Overrides:

available in class java.io.FilterInputStream

Returns:

the number of bytes that can be read from the input stream without blocking.

Throws:

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

close

public void close()
           throws java.io.IOException

Closes this input stream and releases any system resources associated with the stream.

This method will read any unread data in the MIME part so that the next part starts an an expected place in the parent InputStream. Note that if the client code forgets to call this method on error, MultipartParser will call it automatically if you call readNextPart().

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.