Java多线程实践

1.实现Runnable接口

 import java.util.Random;

 public class PrintTask implements Runnable{
     private final int sleepTime;
     private final String taskName;
     private final static Random generator = new Random();

     public PrintTask(String name) {
         taskName = name;
         sleepTime = generator.nextInt(5000);
     }

     @Override
     public void run() {
         try {
             System.out.printf("%s going to Sleep for %d milliseconds.\n",
                     taskName, sleepTime);
             Thread.sleep(sleepTime);
         } catch (InterruptedException e) {
             System.out.printf("%s %s\n", taskName, "terminated prematurely" +
                     " due to interruption");
         }
         System.out.printf("%s done sleeping\n", taskName);
     }

 }

2.使用ExecutorService管理执行PrintTask的线程

 import java.util.Random;

 public class PrintTask implements Runnable{
     private final int sleepTime;
     private final String taskName;
     private final static Random generator = new Random();

     public PrintTask(String name) {
         taskName = name;
         sleepTime = generator.nextInt(5000);
     }

     @Override
     public void run() {
         try {
             System.out.printf("%s going to Sleep for %d milliseconds.\n",
                     taskName, sleepTime);
             Thread.sleep(sleepTime);
         } catch (InterruptedException e) {
             System.out.printf("%s %s\n", taskName, "terminated prematurely" +
                     " due to interruption");
         }
         System.out.printf("%s done sleeping\n", taskName);
     }

 }

3.执行结果

可以看到，由于每个任务随机休眠时间不同，执行结束的顺序是不同的。