我必须通过访问服务器url来验证jvm的可用性。

Question

我正在进行一次单击就可以自动访问多个服务器urls (现在这些urls是手动的)，作为响应，我将为每个响应获得一个登录页面，这意味着jvm已经启动并运行。

问题是jvm可能需要最多5分钟的响应时间，并且有多达10个urls，因此检查响应代码的总时间最多需要50分钟(最糟糕的情况是，所有jvm都关闭)。

所以，我必须做两件事--我们将要点击的服务器urls，在一次点击中应该同步发生(这将使整个响应时间从50分钟大幅度降低到5-6分钟)。我用过PoolingHttpClientConnectionManager方法-

`PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
            CloseableHttpClient httpClient = HttpClients.custom()
            .setConnectionManager(cm)
            .build();


            static int statusCode;

        // Here the servers string array have URLs defined in JSP Page -
<!-- <form name="input" action="welcome"  method="get">
            <input type="checkbox" name="server" value="http://hc.apache.org/" checked>Apache HC Home Page<br>
            <input type="checkbox"  name="server" value="http://hc.apache.org/httpcomponents-core-ga/" checked>HttpCore<br>
            <input type="checkbox"  name="server" value="https://gmail.com" checked>Gmail<br>  -->
       // create a thread for each URI
        public void synchronizeUrls(String[] servers) throws InterruptedException
        {
        GetThread[] threads = new GetThread[servers.length];
        for (int i = 0; i < threads.length; i++) {
            HttpGet httpget = new HttpGet(servers[i]);
            threads[i] = new GetThread(httpClient, httpget);
        }


        // start the threads
        for (int j = 0; j < threads.length; j++) {
            threads[j].start();
        }

        // join the threads
        for (int j = 0; j < threads.length; j++) {
            threads[j].join();
        }
        }




        static class GetThread extends Thread {

            private final CloseableHttpClient httpClient;
            private final HttpContext context;
            private final HttpGet httpget;

            public GetThread(CloseableHttpClient httpClient, HttpGet httpget) {
                this.httpClient = httpClient;
                this.context = HttpClientContext.create();
                this.httpget = httpget;
            }

            @Override
            public void run() {
                try {
                    CloseableHttpResponse response = httpClient.execute(
                            httpget, context);

                    final HttpClientConnectionManager connMgr = null;
                    try {
                    //    HttpEntity entity = response.getEntity();
                        statusCode = response.getStatusLine().getStatusCode();
                        System.out.println(statusCode);

                    }
                }   // Handle protocol errors
                    catch (ClientProtocolException ex) {
                    System.out.println(ex.getMessage());

                } catch (IOException ex) {
                    // Handle I/O errors
                    System.out.println(ex.getMessage());
                } 
            }`

另一件事是，如果我们没有在5分钟的时间间隔内从任何url获得响应，我们就会把这种情况当作jvm关闭。我不知道如何执行我的第二套要求，如果有人能帮助我，那将是很有帮助的。谢谢!

Answer 1

做这件事有多种方法。我这样做的方式如下。

你想做的是：

1. 并行运行线程并捕获每个线程的结果。
2. 5分钟后，检查它们是否还在运行。仍在运行的指示对应的jvm已关闭。

对于步骤1，将statusCode添加到GetThread。您已经在run()中设置了run()。

private StatusCode statusCode;
public StatusCode getStatusCode() {
    return statusCode;
}

对于步骤2，在启动线程块之后添加以下代码：

new java.util.Timer().schedule( 
    new java.util.TimerTask() {
        @Override
        public void run() {
            for (int j = 0; j < threads.length; j++) {
                if(threads[j].getStatusCode().equals(OK)) {
                    //threads[j]'s jvm is up
                } else {
                    //threads[j]'s jvm is down
                }
            }
        }
    }, 
    5 * 60 * 1000
);