Java web service without a web application server

Question

We have a message processing server, which

• start a few threads
• processing the message
• interact with the database etc.....

now the client want to have a web service server on the server, they will be able to querying the message processing server, with a web service client. e.g. give me all the messages for today, or delete the message with id....

the problem are:

• The server just a standard j2se application, doesn't run inside application server, like tomcat or glassfish.
• To handle a Http request, do I need to implement a http server?
• I would like to use the nice j2ee annotation such as @webservice, @webmothod etc... is there any library or framework I can use

Answer 1

You don't need a third party library to use jax-ws annotations. J2SE ships with jax-ws, so all the annotations are still available to you. You can achieve lightweight results with the following solution, but for anything optimized/multi-threaded, it's on your own head to implement:

1. Design a SEI, service endpoint interface, which is basically a java interface with web-service annotations. This is not mandatory, it's just a point of good design from basic OOP.

   import javax.jws.WebService;
   import javax.jws.WebMethod;
   import javax.jws.WebParam;
   import javax.jws.soap.SOAPBinding;
   import javax.jws.soap.SOAPBinding.Style;
   
   @WebService
   @SOAPBinding(style = Style.RPC) //this annotation stipulates the style of your ws, document or rpc based. rpc is more straightforward and simpler. And old.
   public interface MyService{
   @WebMethod String getString();
   
   }
   

2. Implement the SEI in a java class called a SIB service implementation bean.

   @WebService(endpointInterface = "com.yours.wsinterface") //this binds the SEI to the SIB
   public class MyServiceImpl implements MyService {
   public String getResult() { return "result"; }
    }
   

3. Expose the service using an Endpoint import javax.xml.ws.Endpoint;

   public class MyServiceEndpoint{
   
   public static void main(String[] params){
     Endpoint endPoint =  EndPoint.create(new MyServiceImpl());
     endPoint.publish("http://localhost:9001/myService"); //supply your desired url to the publish method to actually expose the service.
      }
   }
   

The snippets above, like I said, are pretty basic, and will perform poorly in production. You'll need to work out a threading model for requests. The endpoint API accepts an instance of Executor to support concurrent requests. Threading's not really my thing, so I'm unable to give you pointers.