如何在Java中以块形式从Web服务返回数据

Question

Hello I am using a webservice which returns a output upon completion of code execution. Is it possible that webservice may return the status in chunks like custom strings: Test Started, Test In Progress, Test Completed etc.

What I need to do to achieve this. Here is my current code where I am expecting a json string as input, supplied json is parsed and further processing is being performed.

//Class
public class WebserviceClient 
{
    /** calling constructor to initialize logger */
    Utils c = new Utils();
    Logger logger = Logger.getLogger(WebserviceClient.class.getName());


    @Path("/test")
    @POST
    @Consumes(MediaType.APPLICATION_JSON)
    //@Produces(MediaType.APPLICATION_JSON)
    public String processRequest(final String inputData)
    {
        String executionID = "NOT_FOUND" ;
        String result = "";

        try 
        {
            /** creating a pool of threads to submit a task to a callable thread */
            ExecutorService ex = Executors.newFixedThreadPool(5);

            Future<String> futureObject = ex.submit(new Callable<String>() {
                @Override
                public String call() throws Exception 
                {
                    logger.info("Parsing Received Request: "+inputData);
                    String rID = new JSONObject(inputData).getString("id");
                    logger.info("Received Id: "+rID + " From Request: "+inputData);

                    if(new RunTest().isTestCompleted(rID))
                    {
                        return rID;
                    }
                    else
                    {
                        return "777";
                    }
                }
            });

            result = futureObject.get();

            if(futureObject.get()!=null)
            {
                ex.shutdown();
            }
            else{
                logger.debug("call id: "+executionID +" result is not generated yet. ");
            }

            logger.info("call id && Result: "+result);
        }
        catch(Exception e) 
        {
            logger.error("call id: "+executionID, e);
        }
        return result;
    }
}

Answer 1

You need to do a continuous polling to the server at high frequency to achieve the current status.

For little more information have a look at the :

Continuous polling of output using spring ,rest and angular js

This includes design consideration of using WebSockets etc, but there is no straight forward solution that I'm aware of.