java 线程池使用 Runnable&Callable&Future

java 线程池使用 Runnable&Callable&Future

Java  /  管理员 发布于 2020-03-08 13:33:15   24

1. 创建线程池

ExecutorService executorService = Executors.newCachedThreadPool();

 

2. 执行一次线程，调用Runnable接口实现

Future<?> future = executorService.submit(new DefaultRunnable());System.out.println(future.get());

 当线程池执行Runnable后，返回的Future.get()总是null

 

DefaultRunnable代码如下:

package threadpool;public class DefaultRunnable implements Runnable {private int count = 1;@Overridepublic void run() {System.out.println("the count in default runnable is ["+count+++"]");}}

 

3. 执行一次线程，调用Callable接口实现

Future<?> future = executorService.submit(new DefaultCallable());System.out.println(future.get());

 当线程池执行Callable时，返回的Future.get() 会返回Callable的返回值

 

DefaultCallable代码如下:

package threadpool;import java.util.concurrent.Callable;public class DefaultCallable implements Callable<Object> {private int count =1;@Overridepublic Object call() throws Exception {return count++;}}

 

4. 关闭线程池

executorService.shutdown();