Java多线程

创建线程三种方式

1. 继承Thread类，重写run方法

   class Thread1 extends Thread {
       @Override
       public void run() {
           System.out.println("当前线程" + Thread.currentThread().getName());
       }
   }
   //测试
   Thread t1 = new Thread1();
   t1.setName("t1");
   t1.start();
   

2. 实现Runable接口，实现run方法

   class Thread2 implements Runnable {
       @Override
       public void run() {
           System.out.println("当前线程" + Thread.currentThread().getName());
       }
   }
   //测试
   Thread2 t2 = new Thread2();
   new Thread(t2 , "t2").start();
   

3. 实现Callable接口，重写call()方法。有返回值

   class Thread3 implements Callable<String> {
       @Override
       public String call() throws Exception {
           System.out.println("当前线程" + Thread.currentThread().getName());
           return "ok";
       }
   }
   //测试
   Thread3 t3 = new Thread3();
   FutureTask<String> ft3 = new FutureTask<>(t3);
   new Thread(ft3).start();
   System.out.println(ft3.get());
   

线程的周期