webService是一種跨語言的系統間互動標準。在java中使用webservice根據伺服器端的服務根據描述生成WSDL檔案，並將應用與此WSDL檔案一起放入HTTP伺服器中，藉助服務工具根據WSDL檔案生成客戶端STUB程式碼。此程式碼的作用是將產生的物件請求資訊封裝成標準的SOAP格式資料，併發送到伺服器端，伺服器端根據接收到的SOAP格式資料進行轉換，並最終通過反射呼叫響應類的響應方法。

jdk 6中集成了WEB service的支援，通過WebService 的annotation來暴露服務的實現，並通過Endpoint.publish將服務釋出到指定的地址，客戶端通過wsimport來訪問響應地址的wsdl檔案，生成呼叫伺服器端服務的stub類資訊，客戶端即可通過生成的類來呼叫伺服器的服務了。

具體示例如下：

1.對外暴露的介面

package helloworld;

public interface TestWebService {

	public String echo();
}

2.伺服器端的實現類，並通過@WebService來指定對外提供服務的服務名稱，客戶端生成的類目和包名

package helloworld;

import javax.jws.WebService;
import javax.xml.ws.Endpoint;


@WebService(name="MyTestWS",serviceName="MyWebService",targetNamespace="http://localhost/client")
public class WebServiceImpl implements TestWebService{

	public String echo() {
		return "webservice return msg";
	}
	
	public static void main(String[] args) {
		Endpoint.publish("http://localhost:8080/MyWebService", new WebServiceImpl());
	}
}
 

3.然後執行伺服器的WebServiceImpl的main函式，暴露服務並將服務註冊到一個http服務地址上，客戶端通過jdk的bin下面的wsimport命令來獲取伺服器的wsdl檔案並生成客戶端的stub類資訊開啟dos視窗找到專案路徑執行一下程式碼

wsimport -keep http://localhost:8080/MyWebService?wsdl

此處可改為 wsimport -keep -p com.localhost.client http://localhost:8080/MyWebService?wsdl com.localhost.client是自己定義的包預設用targetNamespace=

將出現編譯好的java檔案貼上到專案中

4.然後在你的路徑上就會生成下面幾個類

注：test.java 是測試類

5.然後我們編寫客戶端的呼叫程式碼

package localhost.client;

public class test {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		MyWebService myservice  = new MyWebService();
		System.out.println(myservice.getMyTestWSPort().echo());
	}

}

6.執行客戶端的呼叫程式碼，輸出如下：

配置web.xml

 <listener> 

       <listener-class> 

                com.sun.xml.ws.transport.http.servlet.WSServletContextListener 

       </listener-class> 

  </listener> 

 

 

  <servlet> 

       <servlet-name>TestService</servlet-name> 

       <servlet-class> 

               com.sun.xml.ws.transport.http.servlet.WSServlet 

       </servlet-class> 

  </servlet> 

       

  <servlet-mapping> 

       <servlet-name>TestService</servlet-name> 

       <url-pattern>/hello</url-pattern> 

  </servlet-mapping> 

程式碼

<?xml version="1.0" encoding="UTF-8"?>
<endpoints xmlns='http://java.sun.com/xml/ns/jax-ws/ri/runtime' version='2.0'>   
    <endpoint name="TestService" implementation="helloworld.WebServiceImpl" url-pattern="/hello" />
</endpoints>

出現頁面

將MyWebService程式碼改為

package localhost.client;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.logging.Logger;
import javax.xml.namespace.QName;
import javax.xml.ws.Service;
import javax.xml.ws.WebEndpoint;
import javax.xml.ws.WebServiceClient;
import javax.xml.ws.WebServiceFeature;


/**
 * This class was generated by the JAX-WS RI.
 * JAX-WS RI 2.1.6 in JDK 6
 * Generated source version: 2.1
 * 
 */
@WebServiceClient(name = "MyWebService", targetNamespace = "http://localhost/client", wsdlLocation = "http://localhost/MyWebService?wsdl")
public class MyWebService
    extends Service
{

    private final static URL MYWEBSERVICE_WSDL_LOCATION;
    private final static Logger logger = Logger.getLogger(localhost.client.MyWebService.class.getName());

    static {
        URL url = null;
        try {
            URL baseUrl;
            baseUrl = localhost.client.MyWebService.class.getResource(".");
            url = new URL(baseUrl, "http://localhost/javawebservice/hello?wsdl");
        } catch (MalformedURLException e) {
            logger.warning("Failed to create URL for the wsdl Location: 'http://localhost/MyWebService?wsdl', retrying as a local file");
            logger.warning(e.getMessage());
        }
        MYWEBSERVICE_WSDL_LOCATION = url;
    }

    public MyWebService(URL wsdlLocation, QName serviceName) {
        super(wsdlLocation, serviceName);
    }

    public MyWebService() {
        super(MYWEBSERVICE_WSDL_LOCATION, new QName("http://localhost/client", "MyWebService"));
    }

    /**
     * 
     * @return
     *     returns MyTestWS
     */
    @WebEndpoint(name = "MyTestWSPort")
    public MyTestWS getMyTestWSPort() {
        return super.getPort(new QName("http://localhost/client", "MyTestWSPort"), MyTestWS.class);
    }

    /**
     * 
     * @param features
     *     A list of {@link javax.xml.ws.WebServiceFeature} to configure on the proxy.  Supported features not in the <code>features</code> parameter will have their default values.
     * @return
     *     returns MyTestWS
     */
    @WebEndpoint(name = "MyTestWSPort")
    public MyTestWS getMyTestWSPort(WebServiceFeature... features) {
        return super.getPort(new QName("http://localhost/client", "MyTestWSPort"), MyTestWS.class, features);
    }

}

再次呼叫test方法返回