Java 在腹板承座连接上安装弹簧

我的目标是将一个请求从前端发送到后端，并接收多个响应。我之所以使用WebSocket，是因为响应非常频繁，而且WebSocket似乎是最好的协议，可以从后端发送多个响应

这是我的请求控制器：

@MessageMapping("/emitter")
@SendTo("/topic/response")
public SseEmitter output(RunData runData) throws Exception {
    SseEmitter emitter = new SseEmitter();
    new Thread(new Runnable() {

        @Override
        public void run() {
            try {
                RemoteHostController rhc = new RemoteHostController(runData);
                rhc.execute();
                while (rhc.getActiveCount() > 0) {
                    emitter.send(rhc.getAllOutput());
                    Thread.sleep(2000);
                }

                 emitter.complete();
            } catch (Exception ee) {
                ee.printStackTrace();
                emitter.completeWithError(ee);
            }
        }
    }).start();

    return emitter;
}

@Controller
public class WebSocketController {
   @Autowired
    SimpMessagingTemplate simpMessagingTemplate;

    @MessageMapping("/processrequest")
    void runWebSocket( RequestData requestData ) {
        new Thread(new RunProcess(requestData)).start();
    }

    private class RunProcess implements Runnable {
        private RequestData requestData;

        RunProcess(RequestData requestData) {
            this.requestData = requestData;
        }

        public void run() {
            simpMessagingTemplate.convertAndSend("/topic/response", requestData.getString1());
            simpMessagingTemplate.convertAndSend("/topic/response", requestData.getString2());
            simpMessagingTemplate.convertAndSend("/topic/response", "A third response via websocket");
        }
    }
}

@Controller
public class SseController {

    @RequestMapping("/emitter")
    public SseEmitter runEmitter(@RequestParam(value = "string1") String string1,
                                 @RequestParam(value = "string2") String string2)
    {
        SseEmitter sseEmitter = new SseEmitter();
        RequestData requestData = new RequestData();
        requestData.setString1(string1);
        requestData.setString2(string2);
        new Thread(new RunProcess(requestData,sseEmitter)).start();
        return sseEmitter;
    }

    private class RunProcess implements Runnable {
        private RequestData requestData;
        private SseEmitter sseEmitter;

        RunProcess(RequestData requestData, SseEmitter sseEmitter) {
            this.requestData = requestData;
            this.sseEmitter = sseEmitter;
        }

        public void run() {
            try {
                sseEmitter.send(requestData.getString1());
                sseEmitter.send(requestData.getString2());
                sseEmitter.send("A third response from SseEmitter");
                sseEmitter.complete();
            } catch (IOException e) {
                e.printStackTrace();
                sseEmitter.completeWithError(e);
            }
        }
    }

}

RemoteHostController正在管理连接，getAllOutput返回来自主机的输出

前端应用程序正在运行非常简单的index.html，它使用Stomp和SockJS连接到websocket，将数据发送到服务器，并使用响应中的数据生成标记：

function connect() {
        var socket = new SockJS('http://localhost:8080/emitter');
        stompClient = Stomp.over(socket);
        stompClient.connect({}, function(frame) {
            setConnected(true);
            console.log('Connected: ' + frame);
            stompClient.subscribe('/topic/response', function(greeting){
                showOutput(greeting.body);
            });
        });
}

function sendData() {
        var hostname = document.getElementById('hostname').value;
        var username = document.getElementById('username').value;
        var password = document.getElementById('password').value;
        var command = document.getElementById('command').value;
        stompClient.send("/app/emitter", {}, JSON.stringify({ 'hostname': hostname,
                                                    'username': username,
                                                    'password': password,
                                                    'command': command}));
}

function showOutput(message) {
        var response = document.getElementById('response');
        var p = document.createElement('p');
        p.style.wordWrap = 'break-word';
        p.appendChild(document.createTextNode(message));
        response.appendChild(p);
}

当我将数据发送到后端时，我得到的唯一响应是：

{"timeout":null}

它是一个超时字段，当我更改超时时，它将返回{timeout:}

我可以在日志中看到RemoteHostController正在连接到主机并正确执行命令

---

我做错什么了吗？或者WebSocket只支持一个请求一个响应通信？

这里是WebSocket和SSE的示例。如上所述，IE浏览器不支持SSE。为了完整性，我尽可能多地添加。确保在使用SeeEmitter时没有使用RestController，因为这将返回对象，这是我根据上面的描述猜测的

pom.xml

<dependencies>
    <!-- Spring boot framework -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-websocket</artifactId>
    </dependency>
</dependencies>

请求数据：

public class RequestData {
    private String string1;
    private String string2;
    // excluding getters and setters
}

Web套接字控制器：

@MessageMapping("/emitter")
@SendTo("/topic/response")
public SseEmitter output(RunData runData) throws Exception {
    SseEmitter emitter = new SseEmitter();
    new Thread(new Runnable() {

        @Override
        public void run() {
            try {
                RemoteHostController rhc = new RemoteHostController(runData);
                rhc.execute();
                while (rhc.getActiveCount() > 0) {
                    emitter.send(rhc.getAllOutput());
                    Thread.sleep(2000);
                }

                 emitter.complete();
            } catch (Exception ee) {
                ee.printStackTrace();
                emitter.completeWithError(ee);
            }
        }
    }).start();

    return emitter;
}

@Controller
public class WebSocketController {
   @Autowired
    SimpMessagingTemplate simpMessagingTemplate;

    @MessageMapping("/processrequest")
    void runWebSocket( RequestData requestData ) {
        new Thread(new RunProcess(requestData)).start();
    }

    private class RunProcess implements Runnable {
        private RequestData requestData;

        RunProcess(RequestData requestData) {
            this.requestData = requestData;
        }

        public void run() {
            simpMessagingTemplate.convertAndSend("/topic/response", requestData.getString1());
            simpMessagingTemplate.convertAndSend("/topic/response", requestData.getString2());
            simpMessagingTemplate.convertAndSend("/topic/response", "A third response via websocket");
        }
    }
}

@Controller
public class SseController {

    @RequestMapping("/emitter")
    public SseEmitter runEmitter(@RequestParam(value = "string1") String string1,
                                 @RequestParam(value = "string2") String string2)
    {
        SseEmitter sseEmitter = new SseEmitter();
        RequestData requestData = new RequestData();
        requestData.setString1(string1);
        requestData.setString2(string2);
        new Thread(new RunProcess(requestData,sseEmitter)).start();
        return sseEmitter;
    }

    private class RunProcess implements Runnable {
        private RequestData requestData;
        private SseEmitter sseEmitter;

        RunProcess(RequestData requestData, SseEmitter sseEmitter) {
            this.requestData = requestData;
            this.sseEmitter = sseEmitter;
        }

        public void run() {
            try {
                sseEmitter.send(requestData.getString1());
                sseEmitter.send(requestData.getString2());
                sseEmitter.send("A third response from SseEmitter");
                sseEmitter.complete();
            } catch (IOException e) {
                e.printStackTrace();
                sseEmitter.completeWithError(e);
            }
        }
    }

}

Sse控制器：

@MessageMapping("/emitter")
@SendTo("/topic/response")
public SseEmitter output(RunData runData) throws Exception {
    SseEmitter emitter = new SseEmitter();
    new Thread(new Runnable() {

        @Override
        public void run() {
            try {
                RemoteHostController rhc = new RemoteHostController(runData);
                rhc.execute();
                while (rhc.getActiveCount() > 0) {
                    emitter.send(rhc.getAllOutput());
                    Thread.sleep(2000);
                }

                 emitter.complete();
            } catch (Exception ee) {
                ee.printStackTrace();
                emitter.completeWithError(ee);
            }
        }
    }).start();

    return emitter;
}

@Controller
public class WebSocketController {
   @Autowired
    SimpMessagingTemplate simpMessagingTemplate;

    @MessageMapping("/processrequest")
    void runWebSocket( RequestData requestData ) {
        new Thread(new RunProcess(requestData)).start();
    }

    private class RunProcess implements Runnable {
        private RequestData requestData;

        RunProcess(RequestData requestData) {
            this.requestData = requestData;
        }

        public void run() {
            simpMessagingTemplate.convertAndSend("/topic/response", requestData.getString1());
            simpMessagingTemplate.convertAndSend("/topic/response", requestData.getString2());
            simpMessagingTemplate.convertAndSend("/topic/response", "A third response via websocket");
        }
    }
}

@Controller
public class SseController {

    @RequestMapping("/emitter")
    public SseEmitter runEmitter(@RequestParam(value = "string1") String string1,
                                 @RequestParam(value = "string2") String string2)
    {
        SseEmitter sseEmitter = new SseEmitter();
        RequestData requestData = new RequestData();
        requestData.setString1(string1);
        requestData.setString2(string2);
        new Thread(new RunProcess(requestData,sseEmitter)).start();
        return sseEmitter;
    }

    private class RunProcess implements Runnable {
        private RequestData requestData;
        private SseEmitter sseEmitter;

        RunProcess(RequestData requestData, SseEmitter sseEmitter) {
            this.requestData = requestData;
            this.sseEmitter = sseEmitter;
        }

        public void run() {
            try {
                sseEmitter.send(requestData.getString1());
                sseEmitter.send(requestData.getString2());
                sseEmitter.send("A third response from SseEmitter");
                sseEmitter.complete();
            } catch (IOException e) {
                e.printStackTrace();
                sseEmitter.completeWithError(e);
            }
        }
    }

}

Html代码：

---

看到超时字段的原因是控制器方法返回SSEEmiter，这就是发送到SendTo目标的内容。WebSocket可以异步发送，因此没有实际的请求/响应。我不熟悉SSE，但您似乎需要在客户端使用EventSource，请参见示例。我在我们编写的应用程序中使用了WebSocket，您使用SimpMessageTemplate在后端发送内容。我可能会发布一个解决方案时间许可证，我有一个SSEEmiter的示例，但它是通过EventSource向客户端发送流数据的。你可以在那里检查代码。由于Internet Explorer不支持EventSource，我稍后将转到WebSocket。此外，我认为我不需要WebSocket，我认为它通过@Rob Baly指出的EventSource发送数据