SpringBoot通过feign调用Python的Flask框架下的SSE接口_springboot 调用 flask

Python的Flask框架下的SSE接口代码如下

 
# function to push data to the server
def pushData():
    # randint is just to make every message not look the same
    while True:
        number = randint(0, 9)
 
        print('I push data to the server: {0}'.format(number))
        yield 'data: %s\n\n' % 'I am data that has been pushed to the server: {0}'.format(number)
        time.sleep(1)
 
 
# provide SSE stream to the web browser
@app.route('/sse/stock-price')
def stream():
    return flask.Response(pushData(), mimetype="text/event-stream")

注意：pushData函数一定是一个不断输出的函数，如果只一次性返回，则连接就自动结束！

Springboot的Feign接口调用接口

@FeignClient(name="sse-python",url="http://192.152.1.12:3000/")
public interface SSEFeign {
 
    @GetMapping(value = "/sse/stock-price", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
    feign.Response streamStockPrice( );
}

如果需要通过Springboot的restful通过feign创建一个SSE接口，代码如下：

 
    @Autowired
    SSEFeign sseFeign;
 
    @GetMapping(value = "/stock-price", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
    public SseEmitter streamStockPrice() throws InterruptedException {
        SseEmitter emitter = new SseEmitter();
        emitter.onCompletion(new Runnable() {
            @Override
            public void run() {
                System.out.println("进入了onCompletion");
            }
        });
 
        emitter.onError((e) -> {
//            e.printStackTrace();
            System.out.println("进入了onError");
        });
 
        new Thread(()->{
            feign.Response response = sseFeign.streamStockPrice();
            Response.Body body = response.body();
            InputStream fileInputStream = null;
            try {
                fileInputStream = body.asInputStream();
                byte[] bytes = new byte[1024];
                int len = 0;
                while ((len = fileInputStream.read(bytes)) != -1) {
                    String str=new String(bytes,"utf-8");
                    System.out.println(str);
                    emitter.send(SseEmitter.event().data(str));
                }
                fileInputStream.close();
 
            } catch (IOException e) {
                e.printStackTrace();
            }
        }).start();
        return emitter;
    }

注意，通过feign读取InputStream流不断输出的过程，一定要在异步线程中。