Java多线程入门Ⅱ

线程的让步

线程让出自己占用的CPU资源

• 线程让出资源，不指定让给谁
• 线程让出资源，指定让给谁

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方法1：

public static void yield();

线程实现交替打印

import java.io.*;
import java.util.*;
class MyRunnable implements Runnable{
	private String l;
	private String r;
	public MyRunnable(String fl,String fr) {
		this.l=fl;this.r=fr;
	}
	public void run() {
		for(int i=0;i<30;i++) {
			System.out.print(l+" "+i+" "+r+" ");
			Thread.yield();
		}
	}
}
public class Main {
    public static void main(String[] args) {
        MyRunnable mr1=new MyRunnable("[","]");
        MyRunnable mr2=new MyRunnable("(",")");
        Thread t1=new Thread(mr1);
        Thread t2=new Thread(mr2);
        t1.start();t2.start();
    }
}

方法2：

public final void join() throws InterruptedException 
public final void join(long millis) throws InterruptedException 
public final void join(long millis,int nano) throws InterruptedException 

将两个线程合并为同一个线程，A调用join B，A等到B结束再恢复执行

import java.io.*;
import java.util.*;
class MyRunnable implements Runnable{
	private String l;
	private String r;
	public MyRunnable(String fl,String fr) {
		this.l=fl;this.r=fr;
	}
	public void run() {
		for(int i=0;i<30;i++) {
			System.out.print(l+" "+i+" "+r+" ");
			Thread.yield();
		}
	}
}
public class Main {	
    public static void main(String[] args) {
        MyRunnable mr1=new MyRunnable("[","]");
        Thread t1=new Thread(mr1);
        t1.start();
        for(int i=0;i<30;i++) {
        	if(i==10) {
        		try {
        			System.out.print("Join");
        			t1.join();
        		}catch(InterruptedException e) {
        	        e.printStackTrace();		
        		}
        	}
        	System.out.print("( "+i+" )");
        }
    }
}

方法3：

public final void setDaemon(boolean on) //将某个线程设置为守护线程

方法4：

public static void sleep(long millis)throws InterruptedExcepiton

线程同步

---

方法1：

synchronized 加锁

class Resources{
	synchronized void function1(Thread currThread) {
		for(int i=0;i<300;i++) {
			System.out.println(currThread.getName());
		}
	}
}
class MyThread extends Thread{
	Resources rs;
	public MyThread(String tname,Resources trs) {
		this.setName(tname);
        this.rs=trs;
	}
	public void run() {
		if(this.getName().equals("Thread1")) {
			System.out.println("Thread1启动，等待进入function1");
			rs.function1(this);
		}else {
			System.out.println("Thread2启动，等待进入function1");
			rs.function1(this);
		}
	}
}
public class Main {
    public static void main(String[] args) {
        Resources rs=new Resources();
        MyThread t1=new MyThread("Thread1",rs);
        MyThread t2=new MyThread("Thread2",rs);
        t1.start();t2.start();
    }
｝

方法2：

public final void wait() throws InterruptedException
public final void wait(long timeout) throws InterruptedException
public final void notify()
public final void notifyAll()