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();

for (int i = 0; i < 500; i++)
{
System.out.println(Thread.currentThread().getName() + i);
}
}
}

2 继承Thread类

public class ThreadExtends extends Thread
{
/**
* 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)
{
ThreadExtends tr = new ThreadExtends();
tr.start();

for (int i = 0; i < 500; i++)
{
System.out.println(Thread.currentThread().getName() + i);
}
}
}

二、线程的一些方法

1 sleep

public class SleepThread implements Runnable
{
/**
* 线程运行时执行的方法
*/
public void run()
{
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
*/
public static void main(String[] args)
{
SleepThread tr = new SleepThread();
Thread t = new Thread(tr);
t.start();
for (int i = 0; i < 500; i++)
{
System.out.println(Thread.currentThread().getName() + i);
}
}
}

2 Join

public class JoinThread implements Runnable
{
public void run()
{
for (int i = 0; i < 100; i++)
{
System.out.println(Thread.currentThread().getName() + i);
}
}
}

public class JoinTest
{
public static void main(String[] args)
{
JoinThread jt = new JoinThread();
Thread t = new Thread(jt);
t.start();
try
{
   // 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();
}
catch (InterruptedException e)
{
   e.printStackTrace();
}
for (int i = 0; i < 100; i++)
{
   System.out.println(Thread.currentThread().getName() + i);
}
}

}

3 yield

public class YieldThread extends Thread
{
public void run()
{
for (int i = 0; i < 100; i++)
{
   System.out.println(Thread.currentThread().getName() + i);
   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
{
public static void main(String[] args)
{
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 void run()
{
for (int i = 0; i < 100; i++)
{
System.out.println(Thread.currentThread().getName() + i);
}
}
}

public class PriorityTest
{
/**
* 线程优先级默认是5
*/
public static void main(String[] args)
{
int norm = Thread.NORM_PRIORITY; // 5
int max = Thread.MAX_PRIORITY; // 10
int min = Thread.MIN_PRIORITY; // 1

PriorityThread yt = new PriorityThread();
Thread t1 = new Thread(yt, "t1_");
t1.setPriority(norm + 3);
t1.start();

Thread t2 = new Thread(yt, "t2_");
t2.start();
}
}

补充：软件开发 , Java ,