如何在java中从一个线程运行多个get请求？答案

【问题标题】：How to run multiple get requests from one thread in java?如何在java中从一个线程运行多个get请求？
【发布时间】：2020-01-10 12:41:37
【问题描述】：

我想设置一个有 x 个连接的客户端，其中每个连接都会在每次随机时间向不同的 URL 发送一个新的 GET 请求。

所以我的方法是创建 x 个线程，每个线程将在循环中发送一个 GET 请求（直到程序终止）。我使用的是 Apache MultiThreadedHttpConnectionManager，我将可能的连接数设置为 x。


    ClientHandler(int numberOfClients) {
        this.numberOfClients = numberOfClients;

        connManager = new PoolingHttpClientConnectionManager();
        HttpClientBuilder clientBuilder = HttpClients.custom().setConnectionManager(connManager);

        connManager.setMaxTotal(numberOfClients);
        CloseableHttpClient httpClient = clientBuilder.build();

        generateMultiThreadedClient(httpClient);
    }

    private void generateMultiThreadedClient(CloseableHttpClient httpClient) {

        for (int i = 0; i < numberOfClients; i++) {
            String clientUrl = URL + i;
            HttpGet httpGet = new HttpGet(clientUrl);

            ClientMultiThreaded clientMultiThreaded = new ClientMultiThreaded(httpClient,httpGet, i);
            LOGGER.info(CLIENT_LOG + "A new thread for clientId " + i + " was created.");

            clientMultiThreaded.start();
            LOGGER.info(CLIENT_LOG + "Thread for clientId " + i + " started..");

        }
    }

这是我线程的 run() 方法。

ClientMultiThreaded(CloseableHttpClient httpClient, HttpGet httpGet, int clientId) {
        this.httpClient = httpClient;
        this.clientId = clientId;
        this.httpGet = httpGet;
        randomGenerator = new Random();
    }

    @Override
    public void run() {
        try{
            // Execute request for the first time
            executeRequest(httpGet);

            while (true) {
                int timeToSleep = randomGenerator.nextInt(BOUND_LIMIT) + 1;
                LOGGER.info(CLIENT_LOG + "Thread id " + clientId + " went to sleep for " + timeToSleep / 1000 + " seconds");
                sleep(timeToSleep);

                LOGGER.info(" ------- This is a test log printing for clientId: " +clientId);
                executeRequest(httpGet);
            }
        }catch(Exception e) {
            LOGGER.info(e.getMessage());
        }
    }

    private void executeRequest(HttpGet httpGet) throws IOException {
        CloseableHttpResponse response = httpClient.execute(httpGet);
        LOGGER.info(CLIENT_LOG + "clientId " + clientId + " sent get request to URL " + httpGet.getURI());

        statusCode = this.response.getStatusLine().getStatusCode();
        LOGGER.info(CLIENT_LOG + "Status received for clientId " + clientId + " is: " + statusCode);
    }

问题是我实际上收到了 2 个 GET 请求，然后它就停止了。

【问题讨论】：

标签： java multithreading get-request

【解决方案1】：

您需要关闭响应，使用资源尝试使用以下代码：

private void executeRequest(HttpGet httpGet) throws IOException {
    try (CloseableHttpResponse response = httpClient.execute(httpGet)) {
        LOGGER.info(CLIENT_LOG + "clientId " + clientId + " sent get request to URL " + httpGet.getURI());

        statusCode = this.response.getStatusLine().getStatusCode();
        LOGGER.info(CLIENT_LOG + "Status received for clientId " + clientId + " is: " + statusCode);
    }
}

【讨论】：