Sample 1: Simple Content-Based Routing (CBR) of Messages

Introduction

This sample demonstrates a simple content-based routing where a message is passed through the ESB using the Dumb Client mode. The ESB acts as a gateway to accept all messages and then performs mediation and routing based on message properties or content.

Prerequisites

Refer to Prerequisites section in ESB Samples Setup page.

Building the Sample

1. Start the ESB with sample 1 configuration using the instructions given in Starting Sample ESB Configurations.

2. A message should appear in the command or text Linux console stating the server started successfully.

3. The synapse configuration in the ESB used for message mediation in this sample is provided in <ESB_HOME>/repository/samples/synapse_sample_1.xml as shown below:

<definitions xmlns="http://ws.apache.org/ns/synapse">
    <sequence name="main">
        <in>
            <!-- filtering of messages with XPath and regex matches -->
            <filter source="get-property('To')" regex=".*/StockQuote.*">
                <send>
                    <endpoint>
                        <address uri="http://localhost:9000/services/SimpleStockQuoteService"/>
                    </endpoint>
                </send>
                <drop/>
            </filter>
            <send/>
        </in>
        <out>
            <send/>
        </out>
    </sequence>
</definitions>

4. Deploy the back-end service 'SimpleStockQuoteService' and start the Axis2 server using the instructions given in section Starting Sample Back-End Services.

5. Now you have a running ESB instance and a back-end service deployed. In the next section, we will send a message to the back-end service through the ESB using a sample client.

Executing the Sample

1. The sample client used here is 'Stock Quote Client' which can operate in several modes. For instructions on this sample client and its operation modes, refer to Stock Quote Client. Run each of the following ant command from <ESB_HOME>/samples/axis2Client directory to trigger a sample message to the back-end service. If the message is mediated successfully, it should display an output on the Axis2 server's start-up console.

Dumb Client Mode

Execute the Dumb Client as:

ant stockquote -Dtrpurl=http://localhost:8280/services/StockQuote

Note the ESB receiving a message to which ESB is set as the ultimate receiver. ESB performs a match to the path /StockQuote based on the To EPR in the following location: 

• http://localhost:8280/services/StockQuote