Jersey SSE客户端无法工作

Question

我是Jersey SSE Client API的新手，我有一个Servlet会不断地发送事件。当我从浏览器中调用URL时，我可以看到它正在工作。但是当我尝试使用Jersey SSE客户端调用相同的URL时，它并没有按预期工作，我没有看到任何异常被抛出。

这是我用于此的代码：

SERVLET：

    package com.abc.test;

    import java.io.IOException;
    import java.io.PrintWriter;
    import java.util.Calendar;

    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;

    public class TestStream extends HttpServlet {

    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException {
        res.setContentType("text/event-stream");
        res.setCharacterEncoding("UTF-8");
        PrintWriter printWriter = null;

        while(true)
        {
            try {
                printWriter = res.getWriter();
                printWriter.print("data: Thread Will wait for 10 seconds and push the notifications \n\n");
                printWriter.print("data: " + Calendar.getInstance().getTime() +"\n\n");
                res.flushBuffer();
                Thread.sleep(10000);
            }
            catch(IOException ie) {
                printWriter.close();
                break;
            }
            catch(InterruptedException ie){
                printWriter.close();
                break;
            }
        }

    }

}

Jersey SSE客户端代码:

package com.abc.test;

import javax.ws.rs.client.Client;
import javax.ws.rs.client.ClientBuilder;
import javax.ws.rs.client.WebTarget;
import javax.ws.rs.core.Response;

import org.glassfish.jersey.media.sse.EventSource;
import org.glassfish.jersey.media.sse.InboundEvent;
import org.glassfish.jersey.media.sse.SseFeature;


public class ListenerThread implements Runnable {

private int i = 0;
private Thread t;

public void start() {
    if (t == null) {
        t = new Thread(this);
        t.start();
    }
}

@Override
public void run() {
    EventSource eventSource = null;
    try {
        // TODO Auto-generated method stub
        Client client = ClientBuilder.newBuilder()
                .register(SseFeature.class).build();
        WebTarget target = client.target("http://172.20.14.19:8080/TestStream/SSE");
        eventSource = new EventSource(target) {
            @Override
            public void onEvent(InboundEvent inboundEvent) {
                    System.out.println(inboundEvent.getName() + "; "
                            + inboundEvent.readData(String.class));
            }
        };

        while (i <= 10) {
            try {
                Thread.sleep(6000);
                System.out.println("Printing I value : " + i);
                System.out.println("Is Event Source OPEN : " + eventSource.isOpen());
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    } catch (Throwable t) {
        System.out.println("Inside Throwable");
        t.printStackTrace();
    } finally {
        if (null != eventSource)
            eventSource.close();
    }
}

Jersey Client的onEvent永远不会触发。很感谢能提供任何帮助。如果我漏掉了什么，请告诉我。

谢谢， Pradeep

- PRADEEP REDDY KANDI

Answer 1

由于您正在使用EventSource和EventListener，我认为您需要注册事件并打开 eventSource.register(listener, "EVENT NAME");

eventSource.open();

- kapil das

Answer 2

SseFeature 对于这种分块输出不起作用，我们必须使用 ChunkedInput 来读取事件。

- PRADEEP REDDY KANDI