org.mule.transport.tcp.protocols
Class XmlMessageProtocol

java.lang.Object
  org.mule.transport.tcp.protocols.AbstractByteProtocol
      org.mule.transport.tcp.protocols.XmlMessageProtocol

All Implemented Interfaces:

TcpProtocol

Direct Known Subclasses:

XmlMessageEOFProtocol

public class XmlMessageProtocol
extends AbstractByteProtocol

The XmlMessageProtocol is an application level tcp protocol that can be used to read streaming xml documents. The only requirement is that each document include an xml declaration at the beginning of the document of the form "SHOULD begin with an XML declaration which specifies the version of XML being used" while the xml 1.1 standard contains "Definition: XML 1.1 documents MUST begin with an XML declaration which specifies the version of XML being used". The SHOULD indicates a recommendation that, if not followed, needs to be carefully checked for unintended consequences. MUST indicates a mandatory requirement for a well-formed document. Please make sure that the xml documents being streamed begin with an xml declaration when using this class.

Data are read until a new document is found or there are no more data (momentarily). For slower networks, XmlMessageEOFProtocol may be more reliable.

Also, the default character encoding for the platform is used to decode the message bytes when looking for the XML declaration. Some caution with message character encodings is warranted.

Finally, this class uses a PushbackInputStream to enable parsing of individual messages. The stream stores any pushed-back bytes into it's own internal buffer and not the original stream. Therefore, the read buffer size is intentionally limited to insure that unread characters remain on the stream so that all data may be read later.

Field Summary

Fields inherited from class org.mule.transport.tcp.protocols.AbstractByteProtocol

EOF, NO_STREAM, STREAM_OK

Constructor Summary

XmlMessageProtocol()

Method Summary

protected boolean	isRepeat(int patternIndex, int len, int available) Show we continue reading? This class, following previous implementations, only reads while input is saturated.
Object	read(InputStream is) Reads the input stream and returns a whole message.

Methods inherited from class org.mule.transport.tcp.protocols.AbstractByteProtocol

copy, copy, createResponse, nullEmptyArray, safeRead, safeRead, write, writeByteArray

Methods inherited from class java.lang.Object

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

Constructor Detail

XmlMessageProtocol

public XmlMessageProtocol()

Method Detail

read

public Object read(InputStream is)
            throws IOException

Description copied from interface: TcpProtocol

Reads the input stream and returns a whole message.

Parameters:

is - the input stream

Returns:

an array of byte containing a full message

Throws:

IOException - if an exception occurs

isRepeat

protected boolean isRepeat(int patternIndex,
                           int len,
                           int available)

Show we continue reading? This class, following previous implementations, only reads while input is saturated.

Parameters:

patternIndex - The index of the xml tag (or -1 if the next message not found)

len - The amount of data read this loop (or -1 if EOF)

available - The amount of data available to read

Returns:

true if the read should continue

See Also:

XmlMessageEOFProtocol