线程池Executors、Callable与Future的应用

痛定思痛。 2022-07-19 05:29 202阅读 0赞

package cn.itcast.heima;
    
    import java.util.Random;
    import java.util.concurrent.Callable;
    import java.util.concurrent.CompletionService;
    import java.util.concurrent.ExecutionException;
    import java.util.concurrent.ExecutorCompletionService;
    import java.util.concurrent.ExecutorService;
    import java.util.concurrent.Executors;
    import java.util.concurrent.Future;
    
    /** * Callable与Future的应用 * @ClassName: CallableAndFuture * @Description: TODO * @author honghao * @date 2016年8月10日 下午4:24:33 */
    public class CallableAndFuture { 
        public static void main(String[] args) {
            ExecutorService executorService = Executors.newSingleThreadExecutor();
            Future<String> future = executorService.submit(new Callable<String>() {
                @Override
                public String call() throws Exception {
                    Thread.sleep(1000);
                    return "hello";
                }
            });
            try {
                System.out.println("等待结果");
                System.out.println(future.get());
                executorService.shutdown();
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (ExecutionException e) {
                e.printStackTrace();
            }
    
            ExecutorService executorService2 = Executors.newFixedThreadPool(10);
            CompletionService<Integer> completionService = new ExecutorCompletionService<Integer>(
                    executorService2);
            for (int i = 0; i < 10; i++) {
                final int seq = i;
                completionService.submit(new Callable<Integer>() {
                    @Override
                    public Integer call() throws Exception {
                        return seq;
                    }
                });
            }
    
            for (int i = 0; i < 10; i++) {
                try {
                    Thread.sleep(new Random().nextInt(3000));
                    System.out.println(completionService.take().get());
                } catch (InterruptedException e) {
                    e.printStackTrace();
                } catch (ExecutionException e) {
                    e.printStackTrace();
                }
            }
            executorService.shutdown();
            executorService2.shutdown();
        }
    }