常见异步使用方式

1.使用thread启动一个线程执行耗时任务；

Thread t1 = new Thread(new MyThread());
t1.start();

2.使用Exectors创建线程池执行多个耗时任务；

ExecutorService executorService = Executors.newFixedThreadPool(2);
for (int i=0;i<1;i++){
   executorService.execute(new Runnable() {
      public void run() {
         System.out.println("test");
      }
   });
}

3.使用future方式执行异步耗时任务；

ExecutorService threadPool = Executors.newSingleThreadExecutor();
        Future<Integer> future = threadPool.submit(new Callable<Integer>() {
            public Integer call() throws Exception {
                return new Random().nextInt(100);
            }
        });

4.其他开源框架提供的异步方案(如asynchttpclient，httpasyncclient等)；

CloseableHttpAsyncClient httpclient = HttpAsyncClients.createDefault();
try {
    httpclient.start();
    HttpGet request = new HttpGet("http://abc/get");
    Future<HttpResponse> future = httpclient.execute(request, null);
    HttpResponse response = future.get();
    System.out.println("Response: " + response.getStatusLine());
    HttpEntity httpEntity = response.getEntity();
    InputStream inputStream = httpEntity.getContent();
    try {
        String body;
        final StringBuilder sb = new StringBuilder();
        final char[] tmp = new char[1024];
        final Reader reader = new InputStreamReader(inputStream);
        int l;
        while ((l = reader.read(tmp)) != -1) {
            sb.append(tmp, 0, l);
        }
        body = sb.toString();
        System.out.println(body);
    } finally {
        inputStream.close();
        EntityUtils.consume(httpEntity);
    }
    System.out.println("Shutting down");
} finally {
    httpclient.close();
}
System.out.println("Done");