通过java提供的“wsimport”工具可以很容易完成基于SOAP协议的web服务客户端生成工作。这个工具可以从对应的WSDL文档的服务描述中生成客户端支持代码或其它相关资源。输入并执行如下命令:
% wsimport
执行后,将会打印出该命令程序的使用帮助。下面我们将通过命令工具对前面的例子TimeServer服务生成客户端开发相关支持代码。启动ch01.ts.TimeServerPublisher程序后,执行如下命令:
% wsimport -keep -p client http://localhost:9876/ts?wsdl
执行后将会在“client”子目录下面产生两个源代码文件和两个与之对应的已经编译好的Class文件。“-p”选项用来指定生成的java包名称,此处使用“client”作为包名称。包名称可以是符合java包命名规则的任何名称,wsimport工具通过指定的包名称创建包对应子目录。“-keep”选项用来指示是否保留编译后的源文件,这个例子中,我们保留源文件留作验证。“-p”选项是比较重要的,这是由于wsimport命令产生的TimeServer.class文件名称同先前编译的服务端点接口(SEI)拥有同样的名字。如果没有指定包名称,wsimport默认使用服务器实现的包名称作为客户端代码包名称,此处将默认用“ch01.ts”作为包名称。简单来说,使用“-p”选项可以防止编译好的SEI文件不被wsimport工具产生的文件覆盖。如果已经将WSDL文档保存在本地(比如,文件被命名为ts.wsdl),那么,wsimport可以写成:
% wsimport -keep -p client ts.wsdl
生成的代码示例如下,由wsimport生成的TimeServer服务接口:
package client;import javax.jws.WebMethod;import javax.jws.WebResult;import javax.jws.WebService;import javax.jws.soap.SOAPBinding;import javax.xml.ws.Action;/** * This class was generated by the JAX-WS RI. * JAX-WS RI 2.2.4-b01 * Generated source version: 2.2 */@WebService(name = "TimeServer", targetNamespace = "http://ts.ch01/")@SOAPBinding(style = SOAPBinding.Style.RPC)public interface TimeServer { /** * @return * returns java.lang.String */ @WebMethod @WebResult(partName = "return") @Action(input = "http://ts.ch01/TimeServer/getTimeAsStringRequest", output = "http://ts.ch01/TimeServer/getTimeAsStringResponse") public String getTimeAsString(); /** * @return * returns long */ @WebMethod @WebResult(partName = "return") @Action(input = "http://ts.ch01/TimeServer/getTimeAsElasedRequest", output = "http://ts.ch01/TimeServer/getTimeAsElasedResponse") public long getTimeAsElased();}
由wsimport生成的TimeServerImplService实现类:
package client;import java.net.MalformedURLException;import java.net.URL;import javax.xml.namespace.QName;import javax.xml.ws.Service;import javax.xml.ws.WebEndpoint;import javax.xml.ws.WebServiceClient;import javax.xml.ws.WebServiceException;import javax.xml.ws.WebServiceFeature;/** * This class was generated by the JAX-WS RI. * JAX-WS RI 2.2.4-b01 * Generated source version: 2.2 */@WebServiceClient(name = "TimeServerImplService", targetNamespace = "http://ts.ch01/", wsdlLocation = "http://localhost:9876/ts?wsdl")public class TimeServerImplService extends Service{ private final static URL TIMESERVERIMPLSERVICE_WSDL_LOCATION; private final static WebServiceException TIMESERVERIMPLSERVICE_EXCEPTION; private final static QName TIMESERVERIMPLSERVICE_QNAME = new QName("http://ts.ch01/", "TimeServerImplService"); static { URL url = null; WebServiceException e = null; try { url = new URL("http://localhost:9876/ts?wsdl"); } catch (MalformedURLException ex) { e = new WebServiceException(ex); } TIMESERVERIMPLSERVICE_WSDL_LOCATION = url; TIMESERVERIMPLSERVICE_EXCEPTION = e; } public TimeServerImplService() { super(__getWsdlLocation(), TIMESERVERIMPLSERVICE_QNAME); } public TimeServerImplService(WebServiceFeature... features) { super(__getWsdlLocation(), TIMESERVERIMPLSERVICE_QNAME, features); } public TimeServerImplService(URL wsdlLocation) { super(wsdlLocation, TIMESERVERIMPLSERVICE_QNAME); } public TimeServerImplService(URL wsdlLocation, WebServiceFeature... features) { super(wsdlLocation, TIMESERVERIMPLSERVICE_QNAME, features); } public TimeServerImplService(URL wsdlLocation, QName serviceName) { super(wsdlLocation, serviceName); } public TimeServerImplService(URL wsdlLocation, QName serviceName, WebServiceFeature... features) { super(wsdlLocation, serviceName, features); } /** * @return * returns TimeServer */ @WebEndpoint(name = "TimeServerImplPort") public TimeServer getTimeServerImplPort() { return super.getPort(new QName("http://ts.ch01/", "TimeServerImplPort"), TimeServer.class); } /** * @param features * A list of {@link javax.xml.ws.WebServiceFeature} to configure on the proxy. * Supported features not in the features
parameter will have * their default values. * @return * returns TimeServer */ @WebEndpoint(name = "TimeServerImplPort") public TimeServer getTimeServerImplPort(WebServiceFeature... features) { return super.getPort(new QName("http://ts.ch01/", "TimeServerImplPort"), TimeServer.class, features); } private static URL __getWsdlLocation() { if (TIMESERVERIMPLSERVICE_EXCEPTION!= null) { throw TIMESERVERIMPLSERVICE_EXCEPTION; } return TIMESERVERIMPLSERVICE_WSDL_LOCATION; }}
由wsimport产生的源文件有3点需要注意。第一,客户端接口client.TimeServer定义了同目标SEI接口TimeServer相同的方法。这些方法包括服务请求操作getTimeAsString和getTimeAsElapsed两个方法。第二,实现类client.TimeServerImplService包括一个无参构造函数,同目标Java客户端TimeClient中构造服务对象时非常地类似。第三,TimeServerImplService类封装了getTimeServerImplPort方法,该方法返回一个client.TimeServer对象实例,该对象实例支持对两个预先定义的web服务操作的调用。
下面利用wsimport工具产生的客户端支持代码来调用web服务,如例:
package client;/** * 使用wsimport生成的代码编写的java服务调用客户端 * @author fuhd */public class TimeClientWSDL { public static void main(String[] args) { TimeServerImplService service = new TimeServerImplService(); TimeServer server = service.getTimeServerImplPort(); System.out.println(server.getTimeAsElased()); System.out.println(server.getTimeAsString()); }}
上面示例中的服务调用客户端和前面的TimeClient客户端在功能上是一样的,但是这个客户端编写起来却非常容易。尤为重要的是,在使用wsimport工具生成client.TimeServerImplService时,像与服务对应的QName和服务端点等这些复杂的细节都被隐藏掉了。
下面是针对采用基于WSDL协议所生成的相关工件(Artifact)编写服务客户端的一些常用做法,比如像这里的TimeServer和TimeServerImplService。
首先,通过wsimport产生的类中的几个构造方法构造服务对象,比如在本例的client.TimeServerImplService类中,无参数的构造方法更可取,因为这样更为简单。然而,在本例中,还是生成了几个拥有多个输入参数的构造方法,用来适应web服务的命名空间(URI)或服务端点(RUL)等变化。当然还可以通过wsimport工具包重新生成基于WSDL的java文件,用在其他客户端开发中。
通过构建的服务对象调用对应的get系列方法,在本例中是getTimeServerImplPort方法。这个方法返回一个封装了web服务操作方法的对象,本例中分别是定义在目标SEI中的getTimeAsString和getTimeAsElapsed方法。