java线程学习1——线程基本概念和操作

一、创建线程的两种方式

1 继承runnable接口

public class threadimprunnable implements runnable

{

 /**

  * 线程运行时执行的方法

  */

 public void run()

 {

  for (int i = 0; i < 500; i++)

  {

   system.out.println(thread.currentthread().getname() + i);

  }

 }

}

public class test

  * 主线程，启动线程必须是start方法

 public static void main(string[] args)

  threadimprunnable tr = new threadimprunnable();

  thread t = new thread(tr);

   t.start();

2 继承thread类

public class threadextends extends thread

  threadextends tr = new threadextends();

  tr.start();

二、线程的一些方法

1 sleep

public class sleepthread implements runnable

  try

   // 该线程进入阻塞状态5秒

   thread.sleep(5000);

   for (int i = 0; i < 500; i++)

   {

    system.out.println(thread.currentthread().getname() + i);

   }

  catch (interruptedexception e)

   // 若调用该线程的interrupt方法，会报该异常，真实程序中可以关闭一些资源

   e.printstacktrace();

public class sleeptest

  * 主线程

  sleepthread tr = new sleepthread();

  thread t = new thread(tr);

  t.start();

2 join

public class jointhread implements runnable

  for (int i = 0; i < 100; i++)

public class jointest

  jointhread jt = new jointhread();

  thread t = new thread(jt);

   // 调用该方法将当前线程（此处是主线程）合并到本线程中，执行完本线程，再执行当前线程

   t.join();

3 yield

public class yieldthread extends thread

   if (i % 10 == 0)

    // 当能被10整除时本线程让出优先级，让其他线程先执行一会，可看到t1_10下面紧接着t2的结果，同样t2_20下面紧接着t1的结果

    yield();

public class yieldtest

  yieldthread yt = new yieldthread();

  thread t1 = new thread(yt, "t1_");

  t1.start();

  thread t2 = new thread(yt, "t2_");

  t2.start();

4 setpriority

public class prioritythread extends thread

public class prioritytest

  * 线程优先级默认是5

  int norm = thread.norm_priority; // 5

  int max = thread.max_priority;   // 10

  int min  = thread.min_priority;  // 1

  prioritythread yt = new prioritythread();

  t1.setpriority(norm + 3);