通过实现callable的call方法可以完成线程的操作，并且返回一个需要的值
package test1; import java.util.ArrayList; import java.util.List; import java.util.concurrent.Callable; import java.util.concurrent.ExecutionException; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Future; public class TaskWithResult implements Callable<String> { // 实现call方法，在方法中输出两句话 public String call() throws Exception { //Thread.sleep(time); System.out.println(Thread.currentThread().getName() + "run..."); Thread.sleep(100); System.out.println(Thread.currentThread().getName() + "test..."); // 返回一个字符串 return Thread.currentThread().getName() + " has executed"; } public static void main(String[] args) throws InterruptedException, ExecutionException { // 用Executors来管理线程 ExecutorService exec = Executors.newCachedThreadPool(); // 用Future来接受返回值 List<Future<String>> results = new ArrayList<Future<String>>(); for(int i=0; i<=10; i++){ // 将返回值放入Future<String>类型的List中去 results.add(exec.submit(new TaskWithResult())); } // 得到返回值 //System.out.println(results.get(0).get()); exec.shutdown(); } }
输出结果
pool-1-thread-1run... pool-1-thread-2run... pool-1-thread-3run... pool-1-thread-4run... pool-1-thread-5run... pool-1-thread-7run... pool-1-thread-8run... pool-1-thread-9run... pool-1-thread-11run... pool-1-thread-6run... pool-1-thread-10run... pool-1-thread-2test... pool-1-thread-1test... pool-1-thread-4test... pool-1-thread-3test... pool-1-thread-9test... pool-1-thread-8test... pool-1-thread-7test... pool-1-thread-5test... pool-1-thread-10test... pool-1-thread-6test... pool-1-thread-11test...
看出来程序不是顺序运行的，而是将每一个线程分时运行。
可以通过Future的get()来得到返回值
pool-1-thread-1test... pool-1-thread-1 has executed pool-1-thread-3test... pool