How to call a web service (described by a wsdl) from java

Question

Knowing nothing of web services, I'm just trying to call some "isAlive" service that is described by a wsdl.

This seems to me like something that should take no more than 2-5 lines of code but I can't seem to find anything but huge long examples involving 3rd party packages etc.

Anyone has any ideas? If it is always suppose to be long maybe a good explanation as to why it has to be so complicated will also be appreciated. I'm using Eclipse and the wsdl is SOAP.

Answer 1

JDK 6 comes with jax-ws, everything you need to develop a client for a web service.

I'm unable to find some simple enough examples to post , but start at https://jax-ws.dev.java.net/

Edit: here's a simple example - a client for this web service: http://xmethods.com/ve2/ViewListing.po?key=427565

C:\temp> md generated
C:\temp>"c:\Program Files\Java\jdk1.6.0_17"\bin\wsimport -keep -d generated http://www50.brinkster.com/vbfacileinpt/np.asmx?wsdl

Create PrimeClient.java which look like:

import javax.xml.ws.WebServiceRef;
import com.microsoft.webservices.*; 
//the above namespace is from the generated code from the wsdl. 

public class PrimeClient {
 //Cant  get this to work.. @WebServiceRef(wsdlLocation="http://www50.brinkster.com/vbfacileinpt/np.asmx?wsdl")
  static PrimeNumbers service;

  public static void main(String[] args) {
    try {
    service = new PrimeNumbers();
      PrimeClient client = new PrimeClient();
      client.doTest(args);
    } catch(Exception e) {
      e.printStackTrace();
    }
  }

  public void doTest(String[] args) {
    try {
      System.out.println("Retrieving the port from the following service: " + service);
      PrimeNumbersSoap pm = service.getPrimeNumbersSoap();
      System.out.println("Invoking the getPrimeNumbersSoap operation ");
      System.out.println(pm.getPrimeNumbers(100));
    } catch(Exception e) {
      e.printStackTrace();
    }
  }
} 

Compile and run:

C:\temp>"c:\Program Files\Java\jdk1.6.0_17"\bin\javac -cp generated PrimeClient.java
C:\temp>"c:\Program Files\Java\jdk1.6.0_17"\bin\java -cp .;generated PrimeClient
Retrieving the port from the following service: com.microsoft.webservices.PrimeN
umbers@19b5393
Invoking the getPrimeNumbersSoap operation
1,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97

Answer 2

There are plugins for IDE's which generate the needed code to consume a web service for you.

After the plugin generates you the base methods you simply call a web service like that:

TransportServiceSoap service = new TransportServiceLocator().getTransportServiceSoap();
service.getCities();

Have a look at http://urbas.tk/index.php/2009/02/20/eclipse-plug-in-as-a-web-service-client/

Answer 3

There are three ways to write a web service client

1. Dynamic proxy
2. Dynamic invocation interface (DII)
3. Application client

Example for Dynamic Proxy Client

import java.net.URL;

import javax.xml.rpc.Service;

import javax.xml.rpc.JAXRPCException;

import javax.xml.namespace.QName;

import javax.xml.rpc.ServiceFactory;

import dynamicproxy.HelloIF;

public class HelloClient {

    public static void main(String[] args) {
        try {

            String UrlString = "Your WSDL URL";  // 
            String nameSpaceUri = "urn:Foo";
            String serviceName = "MyHelloService";
            String portName = "HelloIFPort";

            System.out.println("UrlString = " + UrlString);
            URL helloWsdlUrl = new URL(UrlString);

            ServiceFactory serviceFactory =
                ServiceFactory.newInstance();

            Service helloService =
                serviceFactory.createService(helloWsdlUrl, 
                new QName(nameSpaceUri, serviceName));

            dynamicproxy.HelloIF myProxy = 
                (dynamicproxy.HelloIF) 
                helloService.getPort(
                new QName(nameSpaceUri, portName), 
                dynamicproxy.HelloIF.class); 

            System.out.println(myProxy.sayHello("Buzz"));

        } catch (Exception ex) {
            ex.printStackTrace();
        } 
    } 
}  

I hope , this would solve your question.

Answer 4

到目前为止，我发现最容易使用的是 Idea IntelliJ 向导，它使用 Metro 库生成一个非常小的代码片段，可以很好地与 Java 6 配合使用。