Java 如何用SSE实现消息推送

IT小马哥

发布于 2024-08-15 13:58:56

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代码可运行

文章被收录于专栏：Java TaleJava Tale

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代码可运行

定义存储池

       /**
	 * 用于存储SseEmitter对象
	 */
	private static final Map<String, SseEmitter> pool = new ConcurrentHashMap<>();

发布消息

       /**
	 * 描述 发布消息
	 * @param id
	 * @param message
	 */
	@PostMapping("/publisher/{id}")
	public void publish(@PathVariable String id, @RequestBody String message) {
		SseEmitter sseEmitter = pool.get(id);
		if(Objects.nonNull(sseEmitter)){
			try {
				sseEmitter.send(message);
			} catch (Exception e) {
				throw  new RuntimeException(e);
			}
		}
	}

订阅消息

       /**
	 * 描述 订阅消息
	 * @param id
	 * @return
	 */
	@GetMapping("/subscribe/{id}")
	public SseEmitter subscribe(@PathVariable String id) {
		SseEmitter sseEmitter = pool.get(id);
		if(Objects.isNull(sseEmitter)){
			sseEmitter = new SseEmitter();
			sseEmitter.onCompletion(() -> pool.remove(id));
			sseEmitter.onTimeout(() -> pool.remove(id));
			pool.put(id, sseEmitter);
		}

		return sseEmitter;
	}

测试

// 接收消息
curl http://127.0.0.1:8080/subscribe/1

// 发送消息
curl -d "message=1" http://127.0.0.1:8080/publisher/1
curl -d "message=2" http://127.0.0.1:8080/publisher/1
curl -d "message=3" http://127.0.0.1:8080/publisher/1