如何仅使用Java SE创建支持多个客户端请求的Java Web服务？

Question

I have the task of creating a web service that takes requests from multiple clients. I am new to web services so i used this tutorial:

http://www.java-forums.org/blogs/web-service/1145-how-create-java-web-service.html

This is exactly what i am looking for. A web service with no java ee.

It is preferable that is stick with java se, it's a policy that is prefered to be kept.

Now i would like to go one step further and implement the service so that it processes requests from multiple clients that operate on a shared resource.

Ideally i would like something like this:

 Client client = new Client();
 client.processRequest(string);

And the web service will process the requests in the order they arrive. The requests will come in as an request is processed so it will be kept in a stack.

The problem is i just on't know how to send the response back to the specific client. The response will be a string. The only thing i came up with, at least in principle, is to send a object that remembers where it came from but that just seems the web services job.

I have searched the internet but did not find a solution.

If possible using only SE please help. If you think it is not possible without EE you can say so, but i would very much like an answer using only SE

Answer 1

I think what you are trying to implement is an Asynchronous Webservice. The following link tells you how to implement it in Java SE.

http://java.dzone.com/articles/asynchronous-java-se-web

Answer 2

You can do this using the Endpoint.publish methods in Java SE. First, you create a simple "endpoint interface":

package com.example;

import javax.jws.WebService;

@WebService
public interface ExampleService {
    String getDateTime();
}

Then you specify that interface in an implementation class. As you can see, both classes must be annotated with @WebService .

package com.example;

import java.io.IOException;
import java.net.URL;
import javax.jws.WebService;
import javax.xml.ws.Endpoint;
import javax.xml.ws.Service;
import javax.xml.namespace.QName;

@WebService(endpointInterface = "com.example.ExampleService",
            serviceName = "ExampleService",
            portName = "timeService",
            targetNamespace = "http://example.com/time")
public class ExampleServiceImpl
implements ExampleService {
    public String getDateTime() {
        return String.format("%tc", System.currentTimeMillis());
    }

    public static void main(String[] args)
    throws IOException {
        // Create server
        Endpoint endpoint =
            Endpoint.publish("http://localhost:8080/example",
                             new ExampleServiceImpl());

        URL wsdl = new URL("http://localhost:8080/example?wsdl");

        // Create client
        Service service = Service.create(wsdl,
            new QName("http://example.com/time", "ExampleService"));
        ExampleService e = service.getPort(ExampleService.class);

        // Test it out
        System.out.println(e.getDateTime());

        endpoint.stop();
    }
}

By default, JAX-WS will treat all public methods of an endpoint interface as web methods (since that is commonly what developers will want). You can have more control by placing the @WebMethod annotation on only the methods you want exposed as web services.

See the JAX-WS specification for all the details.