java中callable的使用

落日映苍穹つ 2023-07-16 15:59 5阅读 0赞

我们知道使用callable可以获得线程中的返回值，下面我们简单介绍callable的使用。

### 1 创建两个callable的实现类 ###

#### 1.1 BumCallable ####

public class BumCallable implements Callable { 
        @Override
        public Object call() throws Exception { 
            try { 
                Thread.sleep(3000);
            } catch (InterruptedException e) { 
                e.printStackTrace();
            }
            return "包子出锅";
        }
    }

#### 1.2 ColdDishCallable ####

public class ColdDishCallable implements Callable { 
        @Override
        public Object call() throws Exception { 
            try { 
                Thread.sleep(1000);
            } catch (InterruptedException e) { 
                e.printStackTrace();
            }
            return "凉菜出锅";
        }
    }

### 2 使用创建好的两个callable的实现类 ###

public class ResultMain { 
    
       static ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(5,10,1000, TimeUnit.SECONDS,new ArrayBlockingQueue<Runnable>(16));
    
        public static void main(String[] args) throws ExecutionException, InterruptedException { 
            long start = System.currentTimeMillis();
            Callable callable1 = new ColdDishCallable();
            /*FutureTask<String> futureTask1 = new FutureTask<String>(callable1); new Thread(futureTask1).start();*/
            Future<String> future1 =  threadPoolExecutor.submit(callable1);
    
            Callable callable2 = new BumCallable();
            /*FutureTask<String> futureTask2 = new FutureTask<String>(callable2); new Thread(futureTask2).start();*/
            Future<String> future2 =  threadPoolExecutor.submit(callable2);
    
            System.out.println(future1.get());
            System.out.println(future2.get());
    
            long end = System.currentTimeMillis();
    
            System.out.println("执行时间："+(end-start));
        }
    }