多线程优先级——Priority

线程的优先级1-10

• 1.NORM_PRIORITY 5 默认
• 2.MIN_PRIORITY 1
• 3.MAX_PRIORITY 10
• 概率，不代表绝对的先后顺序，也就是说优先级为10的并不一定就比优先级为1的先运行，只是它先运行的概率比优先级为1的大，优先级为1-10，不能超过这个范围。
• 一般默认优先级为5.

package thread.lzy.www;
/**
 * 线程的优先级1-10
 * 1.NORM_PRIORITY 5 默认
 * 2.MIN_PRIORITY 1
 * 3.MAX_PRIORITY
 * 概率，不代表绝对的先后顺序
 * @author Administration
 *
 */
public class eProrityTest {

	public static void main(String[] args) {
		System.out.println(Thread.currentThread().getName()+"-->"+Thread.currentThread().getPriority());
		 MyPriority mp=new  MyPriority();
		Thread t1=new Thread(mp,"a");
		Thread t2=new Thread(mp,"b");
		Thread t3=new Thread(mp,"c");
		Thread t4=new Thread(mp,"d");
		Thread t5=new Thread(mp,"e");
		Thread t6=new Thread(mp,"f");
		//设置优先级在启动前
		t1.setPriority(Thread.MAX_PRIORITY);//t1.setPriority(10）;也可以直接写数字1-10都可
		t2.setPriority(Thread.MAX_PRIORITY);
		t3.setPriority(Thread.MAX_PRIORITY);
		t4.setPriority(Thread.MIN_PRIORITY);
		t5.setPriority(Thread.MIN_PRIORITY);
		t6.setPriority(Thread.MIN_PRIORITY);
		
		t1.start();
		t2.start();
		t3.start();
		t4.start();
		t5.start();
		t6.start();
		 
	}
}
class MyPriority implements Runnable{

	@Override
	public void run() {
		
		System.out.println(Thread.currentThread().getName()+"-->"+Thread.currentThread().getPriority());
	}
	
}

代码中a，b，c的优先级为10。d，e，f的优先级为1，但真的就是a，b，c先运行吗 ，答案不是的，
某次运行结果：
main–>5
a–>10
b–>10
e–>1
c–>10
d–>1
f–>1
可以看出c虽然优先级高于e，但并没有先运行，只是它的概率高而已