Fail to create a JSF page as client

[卢杨 <ly...@hotmail.com>]

Dear Developers,

I would like to use JSF to create a client a this is my JSF code and bean code:

 <h:form> 
 <h:inputText value="#{clientBean.echoarg}"></h:inputText>
 <h:commandButton  value="Go!" action="#{clientBean.operation}"></h:commandButton>
 </h:form>

 public String operation()
 {
  System.out.println(echoarg);
      try {
      //instantiate the stub
       EchoServiceStub stub = new EchoServiceStub();
    System.out.println(echoarg);

       EchoServiceStub.Echo 
          request =  new EchoServiceStub.Echo();
       //fill up the request object
        request.setArgs0(echoarg);
       //send and get the response
        EchoServiceStub.EchoResponse 
           response=stub.echoString(request);
              System.out.println(response.getText());
             } catch (Exception e) {
                e.printStackTrace();
            }
             return ("success");

 }

But it show me these errors:
javax.servlet.ServletException: #{clientBean.operation}: java.lang.NoClassDefFoundError: org/apache/http/HttpResponseFactory
	javax.faces.webapp.FacesServlet.service(FacesServlet.java:277)

What can I do ?

Yours sincerely,
Jason