Friday, May 2, 2014

Write your own service and deploy into Axis2

In this blog, i’m going to implement a simple service “OderProcessingService”, with 2 operations “getPrice” and “update”; and then deploy it into axis2.

Step 1: Get your environment ready

  1. Download and install Java. Set the JAVA_HOME environment variable to the pathname of the directory into which you installed the JDK release.
  2. Download and install Tomcat to the a directory [CATALINA_HOME]; you can access its service at http://localhost:8080
  3. Download the newest version of Axis2; WAR distribution and Standard distribution
  4. Install Axis2 WAR distribution on Tomcat; drop the .war file at CATALINA_HOME\webapps and restart Tomcat; make sure the deployment accessing http://localhost:8080/axis2
  5. Install Axis2 standard distribution; upzip the distribution to a directory; [AXIS2_HOME]
  6. Add all .jar files in AXIS2_HOME\lib\* to the CLASSPATH


Step 2: Create the service


package com.wso2.orderprocessing.service;

import java.util.HashMap;
import java.util.Map;

public class OrderProcessingService {
   
   private Map<String, Double> orderMap = new HashMap<String, Double>(0);
   
   public double getPrice(String symbol) {
       Double price = (Double) orderMap.get(symbol);
       if(price != null){
           return price.doubleValue();
       }
       return 42.00;
    }

    public void update(String symbol, double price) {
      orderMap.put(symbol, new Double(price));
    }    
}


Step 3: Create the service.xml


<?xml version="1.0" encoding="UTF-8"?>
<service name="OrderProcessingService" scope="application">
    <description>
       Order Processing Service
    </description>
   
    <parameter name="ServiceClass">com.wso2.orderprocessing.service.OrderProcessingService</parameter>
   
    <operation name="getPrice">
       <messageReceiver class="org.apache.axis2.rpc.receivers.RPCMessageReceiver"/>
    </operation>
    <operation name="update">
       <messageReceiver class="org.apache.axis2.rpc.receivers.RPCInOnlyMessageReceiver"/>
    </operation>    
</service>


services.xml file informs the axis about the service.


Step 4: Package the service

Service need to be packaged in a certain format in order to deploy in Axis2.
[The package must be a .jar file with the compiled Java classes and a META-INF folder which holds the services.xml file. The jar file can be name .aar to distinguish it as an Axis2 service archive. The file name before ".aar" should be the name of the service]




1. Compile the service and put it on the target folder
2. Copy services.xml file to META-INF folder
3. Create .aar file >> jar -cvf OrderProcessingService.aar *


Step 5: Deploy the service

Copy the OrderProcessingService.aar file to CATALINA_HOME/webapps/axis2/WEB-INF/services/ and restart the tomcat

Go to the http://localhost:8080/axis2/services/listServices URL then you can see the OrderProcessingService listed there as follows




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