Content

• Introduction
• How to Start the TCPServer
• How to Send SOAP Messages Using TCP Transport
• Samples
• Transport Components

Introduction

Axis2 supports TCP as a transport. It has support for both send and receive SOAP Messages via TCP. TCP transport does not have any application level headers and the SOAP Message that is sent should be self contained. This makes the interaction fast and simple. However, since there are no application headers, it does not have the privilege of having request URI, and Service dispatching should be done by an alternative method. Thus, RequestURIBasedDispatcher can not be used. The following are the two main alternatives available for dispatching in the Axis2 environment:

1. Use the name space URI of the first child element of SOAPBody. (SOAPMessageBodyBasedDispatcher).
2. Enable WS-Addressing. In the case of version 1.1 and 1.1.1 releases Addressing is default (SOAPActionBasedDispatcher).

When the TCP request is sent it is the user's responsibility to use either Addressing or SOAP body base mechanism.

How to Start the TCPServer

The TCP server can be started by running the class org.apache.axis2.transport.tcp.TCPServer with two parameters - repository and port number, as arguments. This class needs all the Axis dependency jars in the classpath. New services can be added in the usual way by dropping the archives to the repository (See Advance User's Guide for more information)

How to Send SOAP Messages Using TCP Transport

TCP transport can be enabled easily from the call API. The following code segment demonstrates how it can be done.

OMElement payload = ...
ServiceClient serviceClient = new ServiceClient();
Options options = new Options();
options.setTo(targetEPR);

serviceClient.setOptions(options);

OMElement response = serviceClient.sendReceive(payload);

The transport that should be invoked is inferred from the targetEPR (tcp://...). In this case it is TCP and the listener, also TCP . SOAP Message has to be self contained in order to use Addressing. The other option is to use the URI of the first child of the SOAP Body to dispatch the service. The Parameter is of the type OMElement, the XML representation of Axis2.

Samples

Sample for a TCP Client can be found from the samples/userguide/src/userguide/clients/TCPClient.java in the binary distribution. This accesses the same Web service explained in the Axis2 Advacnce User's Guide. The client first starts the TCPServer with the same repository used for the Axis2 Advance User's Guide samples. Since sample is already deployed in the repository while trying the userguide it will be automatically available.

In order to run the TCPClient.java, addressing should be engaged both in the client and server sides. In client side, you can engage addressing by copying the addressing-1.1.1.mar (AXIS2_HOME/repository/module) to AXIS2_HOME/lib directory.

Transport Components

Axis2 TCP transport has two components, a transport Listener for receiving the Messages and transport Sender to send the SOAP Messages. Axis2 installation has both the components built in to itself by default. In the axis2.xml configuration file the two TCP transport components would look as follows.

If the TCP server is started manually this configuration does not take effect. In return this effects the transport Listener's start by Axis2. (e.g. Listener started by the Complete Async interaction)

The following xml lines initializes the TCPTransport Receiver:

<transportReceiver name="tcp" class="org.apache.axis2.transport.tcp.TCPServer">
    <parameter name="port" locked="false">6060</parameter>
</transportReceiver>

The following xml lines adds the TCPTransport Sender:

<transportSender name="tcp" class="org.apache.axis2.transport.tcp.TCPTransportSender"/>