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Task Scheduling using a Simple Trigger¶

This example demonstrates the concept of tasks and how a simple trigger works. Here the MessageInjector class is used, which injects a specified message to the Micro Integrator environment. You can write your own task class implementing the org.apache.synapse.startup.Task interface and implement the execute method to run the task.

If the task should send the message directly to the endpoint through the main sequence, the endpoint address should be specified. For example, if the address of the endpoint is http://localhost:9000/services/SimpleStockQuoteService, the Synapse configuration of the scheduled task will be as shown below.

Synapse configurations¶

Following are the integration artifacts that we can used to implement this scenario. See the instructions on how to build and run this example.

Scheduled Task

<?xml version="1.0" encoding="UTF-8"?>
<task class="org.apache.synapse.startup.tasks.MessageInjector" group="synapse.simple.quartz" name="CheckPrice" xmlns="http://ws.apache.org/ns/synapse">
    <trigger interval="5"/>
    <property name="soapAction" value="urn:getQuote" xmlns:task="http://www.wso2.org/products/wso2commons/tasks"/>
    <property name="to" value="http://localhost:9000/services/SimpleStockQuoteService" xmlns:task="http://www.wso2.org/products/wso2commons/tasks"/>
    <property name="format" value="soap11" xmlns:task="http://www.wso2.org/products/wso2commons/tasks"/>
    <property name="message" xmlns:task="http://www.wso2.org/products/wso2commons/tasks">
        <m0:getQuote xmlns:m0="http://services.samples">
            <m0:request>
                <m0:symbol>IBM</m0:symbol>
            </m0:request>
        </m0:getQuote>
    </property>
</task>

Main Sequence

<?xml version="1.0" encoding="UTF-8"?>
<sequence name="main" xmlns="http://ws.apache.org/ns/synapse">
    <in>
            <send/>
        </in>
        <out>
            <log level="custom">
                <property name="First_Value" expression="//ns:getQuoteResponse/ns:return/ax21:open/child::text()"
                          xmlns:ax21="http://services.samples/xsd" xmlns:ns="http://services.samples"/>
                <property name="For_the_organization" expression="//ns:getQuoteResponse/ns:return/ax21:name/child::text()"
                          xmlns:ax21="http://services.samples/xsd" xmlns:ns="http://services.samples"/>
                <property name="Last_Value" expression="//ns:getQuoteResponse/ns:return/ax21:last/child::text()"
                          xmlns:ax21="http://services.samples/xsd" xmlns:ns="http://services.samples"/>
            </log>
            <drop/>
        </out>
</sequence>

Build and run¶

Create the artifacts:

Set up ESB Integration Studio.
Create an integration project with an ESB Configs module and an Composite Exporter.
Create the main sequence and a scheduled task with the configurations given above.
Deploy the artifacts in your Micro Integrator.

Set up the back-end service:

Download the back-end service.
Extract the downloaded zip file.
Open a terminal, navigate to the axis2Server/bin/ directory inside the extracted folder.
Execute the following command to start the axis2server with the SimpleStockQuote back-end service:
On MacOS/Linux/CentOS
```
sh axis2server.sh
```
On Windows
```
axis2server.bat
```

When the Micro Integrator is invoked, you will see that the back-end service generates a quote every 5 seconds and that the Micro Integrator receives the stock quote response.

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