请注意,我正在Ubuntu下运行Oracle Java 7.

这是代码：
HelloWorldClient.java

import java.net.MalformedURLException;
import java.net.URL;

import javax.xml.namespace.QName;
import javax.xml.ws.Service;


public class HelloWorldClient {

public static void main(String[] args){
    URL url;
    try {
        url = new URL("http://localhost:8080/WebServiceProject/helloWorld?wsdl");
        QName qname = new QName("http:///","HelloWorldImplService");

        Service service = Service.create(url,qname);

        HelloWorld hello = service.getPort(HelloWorld.class);

         System.out.println(hello.sayHello("mkyong"));
    } catch (MalformedURLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

}

HelloWorld.java

import javax.jws.WebMethod;
import javax.jws.WebService;


@WebService
public interface HelloWorld {

    @WebMethod
    public String sayHello(String name);

}

堆栈跟踪：

Exception in thread "main" java.lang.NullPointerException
at com.sun.xml.internal.ws.model.RuntimeModeler.getPortTypeName(RuntimeModeler.java:1407)
at com.sun.xml.internal.ws.client.WSServiceDelegate.getPort(WSServiceDelegate.java:334)
at com.sun.xml.internal.ws.client.WSServiceDelegate.getPort(WSServiceDelegate.java:354)
at javax.xml.ws.Service.getPort(Service.java:188)
at HelloWorldClient.main(HelloWorldClient.java:18)

在这一行抛出异常：

HelloWorld hello = service.getPort(HelloWorld.class);