春+的WebSocket + STOMP。给特定会话的消息（非用户） [英] Spring+WebSocket+STOMP. Message to specific session (NOT user)
问题描述
我正在尝试在Spring框架上设置基本的消息代理，使用我找到的配方此处
I am trying to set up basic message broker on Spring framework, using a recipe I found here
作者声称它运行良好，但我无法在客户端收到消息，但未发现任何可见错误。
Author claims it has worked well, but I am unable to receive messages on client, though no visible errors were found.
目标：
我想做的事情基本相同 - 一个客户端连接到服务器并请求一些异步操作。操作完成后，客户端应该收到一个事件。重要说明：Spring未对客户端进行身份验证，但来自消息代理的异步后端部分的事件包含其登录，因此我假设存储Login-SessionId对的并发映射以便直接向特定会话发送消息。
What I am trying to do is basically the same - a client connects to server and requests some async operation. After operation completes the client should receive an event. Important note: client is not authenticated by Spring, but an event from async back-end part of the message broker contains his login, so I assumed it would be enough to store concurrent map of Login-SessionId pairs for sending messages directly to particular session.
客户代码：
//app.js
var stompClient = null;
var subscription = '/user/queue/response';
//invoked after I hit "connect" button
function connect() {
//reading from input text form
var agentId = $("#agentId").val();
var socket = new SockJS('localhost:5555/cti');
stompClient = Stomp.over(socket);
stompClient.connect({'Login':agentId}, function (frame) {
setConnected(true);
console.log('Connected to subscription');
stompClient.subscribe(subscription, function (response) {
console.log(response);
});
});
}
//invoked after I hit "send" button
function send() {
var cmd_str = $("#cmd").val();
var cmd = {
'command':cmd_str
};
console.log("sending message...");
stompClient.send("/app/request", {}, JSON.stringify(cmd));
console.log("message sent");
}
这是我的配置。
//message broker configuration
@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig extends AbstractWebSocketMessageBrokerConfigurer{
@Override
public void configureMessageBroker(MessageBrokerRegistry config) {
/** queue prefix for SUBSCRIPTION (FROM server to CLIENT) */
config.enableSimpleBroker("/topic");
/** queue prefix for SENDING messages (FROM client TO server) */
config.setApplicationDestinationPrefixes("/app");
}
@Override
public void registerStompEndpoints(StompEndpointRegistry registry) {
registry
.addEndpoint("/cti")
.setAllowedOrigins("*")
.withSockJS();
}
}
现在，在基本配置后我应该实现一个应用程序事件处理程序，以提供有关客户端连接的会话相关信息。
Now, after basic config I should implement an application event handler to provide session-related information on client connect.
//application listener
@Service
public class STOMPConnectEventListener implements ApplicationListener<SessionConnectEvent> {
@Autowired
//this is basically a concurrent map for storing pairs "sessionId - login"
WebAgentSessionRegistry webAgentSessionRegistry;
@Override
public void onApplicationEvent(SessionConnectEvent event) {
StompHeaderAccessor sha = StompHeaderAccessor.wrap(event.getMessage());
String agentId = sha.getNativeHeader("Login").get(0);
String sessionId = sha.getSessionId();
/** add new session to registry */
webAgentSessionRegistry.addSession(agentId,sessionId);
//debug: show connected to stdout
webAgentSessionRegistry.show();
}
}
到目前为止一切顺利。在IDE中运行我的spring webapp并从两个浏览器选项卡连接我的客户端后，我在IDE控制台中得到了这个：
All good so far. After I run my spring webapp in IDE and connected my "clients" from two browser tabs I got this in IDE console:
session_id / agent_id
-----------------------------
|kecpp1vt|user1|
|10g5e10n|user2|
-----------------------------
好的，现在让我们尝试实现消息机制。
Okay, now let's try to implement message mechanics.
//STOMPController
@Controller
public class STOMPController {
@Autowired
//our registry we have already set up earlier
WebAgentSessionRegistry webAgentSessionRegistry;
@Autowired
//a helper service which I will post below
MessageSender sender;
@MessageMapping("/request")
public void handleRequestMessage() throws InterruptedException {
Map<String,String> params = new HashMap(1);
params.put("test","test");
//a custom object for event, not really relevant
EventMessage msg = new EventMessage("TEST",params);
//send to user2 (just for the sake of it)
String s_id = webAgentSessionRegistry.getSessionId("user2");
System.out.println("Sending message to user2. Target session: "+s_id);
sender.sendEventToClient(msg,s_id);
System.out.println("Message sent");
}
}
从任何地方发送消息的服务应用程序的一部分：
A service to send messages from any part of the application:
//MessageSender
@Service
public class MessageSender implements IMessageSender{
@Autowired
WebAgentSessionRegistry webAgentSessionRegistry;
@Autowired
SimpMessageSendingOperations messageTemplate;
private String qName = "/queue/response";
private MessageHeaders createHeaders(String sessionId) {
SimpMessageHeaderAccessor headerAccessor = SimpMessageHeaderAccessor.create(SimpMessageType.MESSAGE);
headerAccessor.setSessionId(sessionId);
headerAccessor.setLeaveMutable(true);
return headerAccessor.getMessageHeaders();
}
@Override
public void sendEventToClient(EventMessage event,String sessionId) {
messageTemplate.convertAndSendToUser(sessionId,qName,event,createHeaders(sessionId));
}
}
现在，让我们试试吧。我运行我的IDE，打开Chrome并创建了2个选项卡，我连接到服务器。 User1和User2。结果控制台：
Now, let's try to test it. I run my IDE, opened Chrome and created 2 tabs form which I connected to server. User1 and User2. Result console:
session_id / agent_id
-----------------------------
|kecpp1vt|user1|
|10g5e10n|user2|
-----------------------------
Sending message to user2. Target session: 10g5e10n
Message sent
但是，正如我在开头提到的那样 - user2得到了绝对没有，虽然他已连接并订阅/ user / queue / response。也没有错误。
But, as I mentioned in the beginning - user2 got absolutely nothing, though he is connected and subscribed to "/user/queue/response". No errors either.
一个问题是，我究竟错过了哪一点？我已经阅读了很多关于这个主题的文章，但无济于事。
SPR-11309 说这是可能的，也应该有效。也许，id-s不是实际的会话ID-s？
好吧也许有人知道如何监控消息是否真的已被发送，而不是被内部Spring机制删除？
A question is, where exactly I am missing the point? I have read many articles on the subject, but to no avail. SPR-11309 says it's possible and should work. Maybe, id-s aren't actual session id-s? And well maybe someone knows how to monitor if the message actually has been sent, not dropped by internal Spring mechanics?
配置错误：
//WebSocketConfig.java:
....
@Override
public void configureMessageBroker(MessageBrokerRegistry config) {
/** queue prefix for SUBSCRIPTION (FROM server to CLIENT) */
// + parameter "/queue"
config.enableSimpleBroker("/topic","/queue");
/** queue prefix for SENDING messages (FROM client TO server) */
config.setApplicationDestinationPrefixes("/app");
}
....
我花了一天时间调试内部弹簧力学找出它出错的地方：
I've spent a day debugging internal spring mechanics to find out where exactly it goes wrong:
//AbstractBrokerMessageHandler.java:
....
protected boolean checkDestinationPrefix(String destination) {
if ((destination == null) || CollectionUtils.isEmpty(this.destinationPrefixes)) {
return true;
}
for (String prefix : this.destinationPrefixes) {
if (destination.startsWith(prefix)) {
//guess what? this.destinationPrefixes contains only "/topic". Surprise, surprise
return true;
}
}
return false;
}
....
虽然我不得不承认我仍然认为文档提到不要明确配置用户个人队列，因为他们已经存在。也许我错了。
Although I have to admit I still think the documentation mentioned that user personal queues aren't to be configured explicitly cause they "already there". Maybe I just got it wrong.
推荐答案
总的来说它看起来不错，但是你能改变吗？
Overall it looks good, but could you change from
config.enableSimpleBroker("/topic");
到
config.enableSimpleBroker("/queue");
...看看这是否有效？希望这有帮助。
... and see if this works? Hope this help.
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