24.2. The Seam object

Procedure 24.1. Hello World Example

1. To show you how the Seam object works, we will first create a new Seam component called helloAction:

   @Stateless 
   @Name("helloAction") 
   public class HelloAction implements HelloLocal { 
       public String sayHello(String name) { 
           return "Hello, " + name; 
       } 
   }
   

2. We will also need to create a local interface for our new component. In particular, note the @WebRemote annotation, as this is required to make our method accessible via remoting:

   @Local 
   public interface HelloLocal { 
       @WebRemote 
       public String sayHello(String name); 
   }
   

3. This is all the server-side code we require. Next, create a new web page and import the helloAction component:

   <s:remote include="helloAction"/>

4. Add a button to the page to make this an interactive user experience:

   <button onclick="javascript:sayHello()">Say Hello</button>

5. You will also need script that performs an action when the button is clicked:

   <script type="text/javascript">
   function sayHello() {
        var name = prompt("What is your name?");
        Seam.Component.getInstance("helloAction").sayHello(name, sayHelloCallback);
   }
   
   function sayHelloCallback(result) {
       alert(result);
   }
   </script>

6. Now deploy your application and browse to your page. Click the button, and enter a name when prompted. A message box will display the "Hello" message, confirming the call's success. (You can find the full source code for this Hello World example in Seam's /examples/remoting/helloworld directory.)