Webservices in JDK 6

Vivek Pandey

 

Webservices in JDK 6

Posted by  vivekp on December 12, 2006 at 8:33 PM EST
Java SE 6 is out! Among other things it has exciting new end-to-end web services stack  -  JAXWS 2.0 FCS RI. Couple of main things you should know:
  • JAXWS Tools wsimport and wsgen part of JDK
  • Simplified deployment using Endpoint API and light-weight HTTP Server in JDK
  • Uses JAXB 2.0, also part of JDK6, for all data binding needs.
  • Also uses Stax, SAAJ 1.3 for message processing. Both these jars are part of JDK 6.

Web service Endpoint

Lets start with a POJO annotated with @WebService annotation. This annotation tells JAXWS that its a Web Service endpoint. You may like to annotate the methods that will be exposed as web services method with @WebMethod annotation. You dont need to specify it if all the methods will be exposed as web services method.

Calculator.java
 package example;import javax.jws.WebService;import javax.jws.WebService;import javax.xml.ws.Endpoint;@WebService public class Calculator {
    @WebMethod     public int add(int a, int b) {
        return a+b;
    }
    
    public static void main(String[] args){
        // create and publish an endpoint
        Calculator calculator = new Calculator();
        Endpoint endpoint = Endpoint.publish("http://localhost:8080/calculator", calculator);        
    }
}

Now you need to do 2 things to build and publish this endpoint:

  • Run apt to compile and generate required wrapper classes
    • apt -d sample example/Calculator.java
  • Publish
    • java -cp sample example.Calculator

Thats it! You have deployed your web services endpoint. Now, try accessing the deployed WSDL by typing http://localhost:8080/calculator?wsdl in your web browser to see the published WSDL. No need to provide deployment descriptor, starting a container etc. Its all done for you internally by JAXWS using light-weight HTTP server available in JDK 6. In short - extremely fast prototyping!

Web Services Client

Lets see how we develop a client based on proxy.

Run wsimport

You would run wsimport on the deployed WSDL URL:

wsimport -p client -keep http://localhost:8080/calculator?wsdl

This step will generates and compile some classes. Notice -keep switch, you need it to keep the generated Java source files. By default wsimport only leaves behind the compiled class files. In this example the classes that matters are

  • Calculator.java - Service Endpoint Interface or SEI
  • CalculatorService - Generated Service, instantiate it to get the proxy

Invoke the endpoint

CalculatorApp.java

package client;class CalculatorApp {
	public static void main(String args[]){
        /**
         * Instantiate the generated Service
         */ 
    	CalculatorService service = new CalculatorService();
        
        /**
         * Get the port using port getter method generated in CaculatorService
         */
        Calculator calculatorProxy = service.getCalculatorPort();
        
        /**
         * Invoke the remote method
         */
        int result = calculatorProxy.add(10, 20);
        System.out.println("Sum of 10+20 = "+result);
	}
}

Now that you have your client code is ready simply compile it:

javac -cp . CalculatorApp.java

and run:

java -cp . client.CalculatorApp

It will print:

Sum of 10+20 = 30

Running latest JAXWS RI on JDK6

The obvious question might be that how would you use latest JAXWS 2.1 RI on top of JDK6. JAXWS 2.1 RI is feature complete and we are busy fixing bug. For list of JAXWS 2.1 features and plan refer to the JAXWS 2.1 roadmap.

All you need to do is to use Endorsed Directory Mechanism  to point to the lib directory in JAXWS intallation:

Runtime

  • java -cp . -Djava.endorsed.dirs=$JAXWS_HOME/lib client.CalculatorApp

Tools

  • Run the tools from JAXWS distribution
    • export JAXWS_HOME to your JAXWS distribution installation
    • $JAXWS_HOME/bin/wsimport
    • $JAXWS_HOME/bin/wsgen
  • For wsimport set WSIMPORT_OPTS="-Djava.endorsed.dirs=$JAXWS_HOME/lib"
  • For wsgen set WSGEN_OPTS="-Djava.endorsed.dirs=$JAXWS_HOME/lib"

Use JDK 6 to develop your web services application and continue providing feedback to [email protected] and if you find an issue report them at IssueTracker.

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