org.apache.turbine.util.upload
Class MultipartStream

java.lang.Object
  org.apache.turbine.util.upload.MultipartStream

Deprecated. use commons-fileupload instead

public class MultipartStream

extends java.lang.Object

This class can be used to process data streams conforming to MIME 'multipart' format as defined in RFC 1251. Arbitrary large amouns of data in the stream can be processed under constant memory usage.

The format of the stream is defined in the following way:
multipart-body := preamble 1*encapsulation close-delimiter epilogue
encapsulation := delimiter body CRLF
delimiter := "--" boundary CRLF
close-delimiter := "--" boudary "--"
preamble := <ignore>
epilogue := <ignore>
body := header-part CRLF body-part
header-part := 1*header CRLF
header := header-name ":" header-value
header-name := <printable ascii characters except ":">
header-value := <any ascii characters except CR & LF>
body-data := <arbitrary data>


Note that body-data can contain another mulipart entity. There is limited support for single pass processing of such nested streams. The nested stream is required to have a boundary token of the same length as the parent stream (see setBoundary(byte[])).

Here is an exaple of usage of this class.

    try {
        MultipartStream multipartStream = new MultipartStream(input,
                                                              boundary);
        boolean nextPart = malitPartStream.skipPreamble();
        OutputStream output;
        while(nextPart) {
            header = chunks.readHeader();
            // process headers
            // create some output stream
            multipartStream.readBodyPart(output);
            nextPart = multipartStream.readBoundary();
        }
    } catch(MultipartStream.MalformedStreamException e) {
          // the stream failed to follow required syntax
    } catch(IOException) {
          // a read or write error occurred
    }
 

Version:

$Id: MultipartStream.java 278822 2005-09-05 19:53:05Z henning $

Author:

Rafal Krzewski

Nested Class Summary

class	MultipartStream.IllegalBoundaryException Deprecated. Thrown upon attempt of setting an invalid boundary token.
class	MultipartStream.MalformedStreamException Deprecated. Thrown to indicate that the input stream fails to follow the required syntax.

Field Summary

protected byte[]	boundary Deprecated. A byte sequence that partitions the stream.
protected int	boundaryLength Deprecated. The lenght of boundary token plus leading CRLF--.
protected byte[]	buffer Deprecated. The buffer used for processing.
protected int	bufSize Deprecated. The lenght of the buffer used for processing.
protected static int	DEFAULT_BUFSIZE Deprecated. The default lenght of the buffer used for processing.
protected static byte[]	FIELD_SEPARATOR Deprecated. A byte sequence that that follows a delimiter that will be followed by an encapsulation (CRLF).
protected int	head Deprecated. The index of first valid character in the buffer.
static int	HEADER_PART_SIZE_MAX Deprecated. The maximum lenght of header-part that will be processed (10 kilobytes = 10240 bytes.)
protected static byte[]	HEADER_SEPARATOR Deprecated. A byte sequence that marks the end of header-part (CRLFCRLF).
protected java.io.InputStream	input Deprecated. The stream were data is read from.
protected int	keepRegion Deprecated. The amount of data that must be kept in the buffer in order to detect delimiters reliably.
protected static byte[]	STREAM_TERMINATOR Deprecated. A byte sequence that that follows a delimiter of the last encapsulation in the stream (--).
protected int	tail Deprecated. The index of last valid characer in the buffer + 1.

Constructor Summary

MultipartStream(java.io.InputStream input, byte[] boundary)
Deprecated. Constructs a MultipartStream with a defalut size buffer.

MultipartStream(java.io.InputStream input, byte[] boundary, int bufSize)
Deprecated. Constructs a MultipartStream with a custom size buffer.

Method Summary

static boolean	arrayequals(byte[] a, byte[] b, int count) Deprecated. Compares count first bytes in the arrays a and b.
int	discardBodyData() Deprecated. Reads body-data from the current encapsulation and discards it.
protected int	findByte(byte value, int pos) Deprecated. Searches a byte of specified value in the buffer starting at specified position.
protected int	findSeparator() Deprecated. Searches the boundary in buffer region delimited by head and tail.
int	readBodyData(java.io.OutputStream output) Deprecated. Reads body-data from the current encapsulation and writes its contents into the output Stream.
boolean	readBoundary() Deprecated. Skips a boundary token, and checks wether more encapsulations are contained in the stream.
byte	readByte() Deprecated. Reads a byte from the buffer, and refills it as neccessary.
java.lang.String	readHeaders() Deprecated. Reads header-part of the current encapsulation
void	setBoundary(byte[] boundary) Deprecated. Changes the boundary token used for partitioning the stream.
boolean	skipPreamble() Deprecated. Finds the beginning of the first encapsulation.

Methods inherited from class java.lang.Object

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

Field Detail

HEADER_PART_SIZE_MAX

public static final int HEADER_PART_SIZE_MAX

Deprecated.

The maximum lenght of header-part that will be processed (10 kilobytes = 10240 bytes.)

See Also:

Constant Field Values

input

protected java.io.InputStream input

Deprecated.

The stream were data is read from.

boundaryLength

protected int boundaryLength

Deprecated.

The lenght of boundary token plus leading CRLF--.

keepRegion

protected int keepRegion

Deprecated.

The amount of data that must be kept in the buffer in order to detect delimiters reliably.

boundary

protected byte[] boundary

Deprecated.

A byte sequence that partitions the stream.

bufSize

protected int bufSize

Deprecated.

The lenght of the buffer used for processing.

DEFAULT_BUFSIZE

protected static final int DEFAULT_BUFSIZE

Deprecated.

The default lenght of the buffer used for processing.

See Also:

Constant Field Values

buffer

protected byte[] buffer

Deprecated.

The buffer used for processing.

head

protected int head

Deprecated.

The index of first valid character in the buffer. 0 <= head < bufSize

tail

protected int tail

Deprecated.

The index of last valid characer in the buffer + 1. 0 <= tail <= bufSize

HEADER_SEPARATOR

protected static final byte[] HEADER_SEPARATOR

Deprecated.

A byte sequence that marks the end of header-part (CRLFCRLF).

FIELD_SEPARATOR

protected static final byte[] FIELD_SEPARATOR

Deprecated.

A byte sequence that that follows a delimiter that will be followed by an encapsulation (CRLF).

STREAM_TERMINATOR

protected static final byte[] STREAM_TERMINATOR

Deprecated.

A byte sequence that that follows a delimiter of the last encapsulation in the stream (--).

Constructor Detail

MultipartStream

public MultipartStream(java.io.InputStream input,
                       byte[] boundary,
                       int bufSize)
                throws MultipartStream.MalformedStreamException,
                       java.io.IOException

Deprecated.

Constructs a MultipartStream with a custom size buffer.

Note that the buffer must be at least big enough to contain the boundary string, plus 4 characters for CR/LF and double dash, plus at least one byte of data. Too small buffer size setting will degrade performance.

Parameters:

input - The InputStream to serve as a data source.

boundary - The token used for dividing the stream into encapsulations.

bufSize - The size of the buffer to be used in bytes.

Throws:

MalformedStreamException.

IOException.

MultipartStream.MalformedStreamException

java.io.IOException

MultipartStream

public MultipartStream(java.io.InputStream input,
                       byte[] boundary)
                throws java.io.IOException

Deprecated.

Constructs a MultipartStream with a defalut size buffer.

Parameters:

input - The InputStream to serve as a data source.

boundary - The token used for dividing the stream into encapsulations.

Throws:

IOException.

java.io.IOException

Method Detail

readByte

public byte readByte()
              throws java.io.IOException

Deprecated.

Reads a byte from the buffer, and refills it as neccessary.

Returns:

Next byte from the input stream.

Throws:

IOException, - if there isn't any more data available.

java.io.IOException

readBoundary

public boolean readBoundary()
                     throws MultipartStream.MalformedStreamException

Deprecated.

Skips a boundary token, and checks wether more encapsulations are contained in the stream.

Returns:

True if there are more encapsulations in this stream.

Throws:

MultipartStream.MalformedStreamException - if the stream ends unexpecetedly or fails to follow required syntax.

setBoundary

public void setBoundary(byte[] boundary)
                 throws MultipartStream.IllegalBoundaryException

Deprecated.

Changes the boundary token used for partitioning the stream.

This method allows single pass processing of nested multipart streams.

The boundary token of the nested stream is required to be of the same length as the boundary token in parent stream.

Restoring parent stream boundary token after processing of a nested stream is left ot the application.

Parameters:

boundary - A boundary to be used for parsing of the nested stream.

Throws:

IllegalBoundaryException, - if boundary has diffrent lenght than the one being currently in use.

MultipartStream.IllegalBoundaryException

readHeaders

public java.lang.String readHeaders()
                             throws MultipartStream.MalformedStreamException

Deprecated.

Reads header-part of the current encapsulation

Headers are returned verbatim to the input stream, including traling CRLF marker. Parsing is left to the application.

TODO allow limiting maximum header size to protect against abuse.

Returns:

header-part of the current encapsulation.

Throws:

MalformedStreamException, - if the stream ends unexpecetedly.

MultipartStream.MalformedStreamException

readBodyData

public int readBodyData(java.io.OutputStream output)
                 throws MultipartStream.MalformedStreamException,
                        java.io.IOException

Deprecated.

Reads body-data from the current encapsulation and writes its contents into the output Stream.

Arbitrary large amouts of data can be processed by this method using a constant size buffer. (see constructor).

Parameters:

output - The Stream to write data into.

Returns:

the amount of data written.

Throws:

MultipartStream.MalformedStreamException

java.io.IOException

discardBodyData

public int discardBodyData()
                    throws MultipartStream.MalformedStreamException,
                           java.io.IOException

Deprecated.

Reads body-data from the current encapsulation and discards it.

Use this method to skip encapsulations you don't need or don't understand.

Returns:

The amount of data discarded.

Throws:

MultipartStream.MalformedStreamException

java.io.IOException

skipPreamble

public boolean skipPreamble()
                     throws java.io.IOException

Deprecated.

Finds the beginning of the first encapsulation.

Returns:

True if an encapsulation was found in the stream.

Throws:

java.io.IOException

arrayequals

public static boolean arrayequals(byte[] a,
                                  byte[] b,
                                  int count)

Deprecated.

Compares count first bytes in the arrays a and b.

Parameters:

a - The first array to compare.

b - The second array to compare.

count - How many bytes should be compared.

Returns:

true if count first bytes in arrays a and b are equal.

findByte

protected int findByte(byte value,
                       int pos)

Deprecated.

Searches a byte of specified value in the buffer starting at specified position.

Parameters:

value - the value to find.

pos - The starting position for searching.

Returns:

The position of byte found, counting from beginning of the buffer, or -1 if not found.

findSeparator

protected int findSeparator()

Deprecated.

Searches the boundary in buffer region delimited by head and tail.

Returns:

The position of the boundary found, counting from beginning of the buffer, or -1 if not found.