GWT RPC服務分配例外的servlet

Question

我試圖創建與以下錯誤消息打擊了一個簡單的RPC服務：

[tomcat:launch] Apr 3, 2013 12:50:38 AM org.apache.catalina.core.ApplicationContext log 
[tomcat:launch] INFO: Marking servlet SummaryBuilderServiceImpl as unavailable 
[tomcat:launch] Apr 3, 2013 12:50:38 AM org.apache.catalina.core.StandardWrapperValve invoke 
[tomcat:launch] SEVERE: Allocate exception for servlet SummaryBuilderServiceImpl 
[tomcat:launch] java.lang.ClassCastException: com.test.server.SummaryBuilderServiceImpl cannot be cast to javax.servlet.Servlet 
[tomcat:launch]  at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1149) 
[tomcat:launch]  at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:827) 
[tomcat:launch]  at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:129) 
[tomcat:launch]  at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) 
[tomcat:launch]  at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) 
[tomcat:launch]  at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) 
[tomcat:launch]  at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) 
[tomcat:launch]  at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293) 
[tomcat:launch]  at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:861) 
[tomcat:launch]  at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:606) 
[tomcat:launch]  at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) 
[tomcat:launch]  at java.lang.Thread.run(Thread.java:662) 
[tomcat:launch] Apr 3, 2013 12:53:32 AM org.apache.catalina.core.StandardWrapperValve invoke 
[tomcat:launch] INFO: Servlet SummaryBuilderServiceImpl is currently unavailable 

我web.xml具有以下映射

<!-- Summary Builder Service --> 
    <servlet> 
     <servlet-name>SummaryBuilderServiceImpl</servlet-name> 
     <servlet-class>com.test.server.SummaryBuilderServiceImpl</servlet-class> 
    </servlet> 
    <servlet-mapping> 
     <servlet-name>SummaryBuilderServiceImpl</servlet-name> 
     <url-pattern>/test/SummaryBuilder</url-pattern> 
    </servlet-mapping> 

的服務文件是

@RemoteServiceRelativePath("SummaryBuilder") 
public interface SummaryBuilderService extends RemoteService { 
    String sayHelloWorld(); 
} 

和異步版本

public interface SummaryBuilderServiceAsync { 
    void sayHelloWorld(AsyncCallback<String> hello); 
} 

和

public class SummaryBuilderServiceImpl implements SummaryBuilderService { 
    @Override 
    public String sayHelloWorld() { 
     return "Hello World"; 
    } 
} 

我調用它的入口點狀

final SummaryBuilderServiceAsync summaryBuilderService = GWT.create(SummaryBuilderService.class); 

     summaryBuilderService.sayHelloWorld(new AsyncCallback<String>() { 

      @Override 
      public void onSuccess(String arg0) { 
       Window.alert(arg0); 

      } 

      @Override 
      public void onFailure(Throwable arg0) { 
       arg0.printStackTrace(); 
       Window.alert("Failed to create servlet"); 

      } 
     }); 

Answer 1

你忘了延長RemoteServiceServlet實施，這使得您的impl類的servlet。

import com.google.gwt.user.server.rpc.RemoteServiceServlet; 

public class SummaryBuilderServiceImpl extendes 
         RemoteServiceServlet implements SummaryBuilderService { 
    @Override 
    public String sayHelloWorld() { 
     return "Hello World"; 
    } 
} 

How to make an GWT server call(GWT RPC?)