学习多线程3---线程之间的通信

两个线程交替打印

1.使用synchronized，wait，notify关键字实现

package com.hzm.test;
/*
 * 两个线程交替打印
 */
public class Communication {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
	   final Business business = new Business();
       new Thread(new Runnable(){

		@Override
		public void run() {
			// TODO Auto-generated method stub
			for(int j = 0 ;j < 50;j++){
				business.sub(j);
			}
		}
	   }).start();

   	   for(int j = 0 ;j < 50;j++){
   		  business.main(j);
	   }

	}

}
class Business{
	private boolean bShouldSub = true;
	public synchronized void sub(int j){
		/*
		 * if改为while语句更健壮
		 */
		 if(!bShouldSub){
			 try {
				this.wait();
			 } catch (InterruptedException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			 }
		 }

		 for(int i = 0;i < 10;i++){
			   System.out.println("子"+"i= "+i+"j= "+j);
		 }
		 bShouldSub = false;
		 this.notify();

	}
	public synchronized void main(int j){
		 if(bShouldSub){
				try {
				    this.wait();
				}   catch (InterruptedException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
		 }
		 for(int i = 0;i < 10;i++){
			    System.out.println("父"+"i= "+i+"j= "+j);
		 }
		 bShouldSub = true;
		 this.notify();
	}
}

　　使用condition信号量实现线程之间通信

package com.condition;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class ConditionTest {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		final Business business = new Business();
	       new Thread(new Runnable(){

			@Override
			public void run() {

				for(int j = 0 ;j < 50;j++){
					business.sub(j);
				}
			}
		   }).start();

   	   for(int j = 0 ;j < 50;j++){
	   		  business.main(j);
	   }
	}

}

class Business{
    Lock lock = new ReentrantLock();
	Condition condition = lock.newCondition();
	private boolean bShouldSub = true;
	public  void sub(int j){
		/*
		 * if改为while语句更健壮
		 */
		 lock.lock();
		 try{
			 if(!bShouldSub){
				 try {
					//this.wait();
					 condition.await();
				 } catch (Exception e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				 }
			 }

			 for(int i = 0;i < 10;i++){
				   System.out.println("子"+"i= "+i+"j= "+j);
			 }
			 bShouldSub = false;
			// this.notify();
			 condition.signal();
		 }catch(Exception e){
			 e.printStackTrace();
		 }finally{
			 lock.unlock();
		 }
	}
	public void main(int j){
		lock.lock();
		try{
			if(bShouldSub){
					try {
					    //this.wait();
						 condition.await();
					}   catch (Exception e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
			 }
			 for(int i = 0;i < 10;i++){
				    System.out.println("父"+"i= "+i+"j= "+j);
			 }
			 bShouldSub = true;
			 //this.notify();
			 condition.signal();
		}finally{
			lock.unlock();
		}
	}
}

　　三个线程交替打印，使用信号量实现

package com.test;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class ThreeconditionTest {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		final Business business = new Business();
	       new Thread(new Runnable(){

			@Override
			public void run() {

				for(int j = 0 ;j < 50;j++){
					business.sub2(j);
				}
			}
		   }).start();

	       new Thread(new Runnable(){

				@Override
				public void run() {

					for(int j = 0 ;j < 50;j++){
						business.sub3(j);
					}
				}
			   }).start();

	   	   for(int j = 0 ;j < 50;j++){
	   		  business.main(j);
		   }
	}

}
class Business{
	Lock lock = new ReentrantLock();
	Condition condition1 = lock.newCondition();
	Condition condition2 = lock.newCondition();
	Condition condition3 = lock.newCondition();
	private int bShouldSub = 1;
	public  void sub2(int j){
		/*
		 * if改为while语句更健壮
		 */
		 lock.lock();
		 try{
			 if(bShouldSub!=2){
				 try {
					//this.wait();
					 condition2.await();
				 } catch (Exception e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				 }
			 }

			 for(int i = 0;i < 10;i++){
				   System.out.println("子"+"i= "+i+"j= "+j);
			 }
			 bShouldSub = 3;
			// this.notify();
			 condition3.signal();
		 }catch(Exception e){
			 e.printStackTrace();
		 }finally{
			 lock.unlock();
		 }
	}
	public  void sub3(int j){
		/*
		 * if改为while语句更健壮
		 */
		 lock.lock();
		 try{
			 if(bShouldSub !=3){
				 try {
					//this.wait();
					 condition3.await();
				 } catch (Exception e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				 }
			 }

			 for(int i = 0;i < 10;i++){
				   System.out.println("子子"+"i= "+i+"j= "+j);
			 }
			 bShouldSub = 1;
			// this.notify();
			 condition1.signal();
		 }catch(Exception e){
			 e.printStackTrace();
		 }finally{
			 lock.unlock();
		 }
	}
	public void main(int j){
		lock.lock();
		try{
			if(bShouldSub != 1){
					try {
					    //this.wait();
						 condition1.await();
					}   catch (Exception e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
			 }
			 for(int i = 0;i < 10;i++){
				    System.out.println("父"+"i= "+i+"j= "+j);
			 }
			 bShouldSub = 2;
			 //this.notify();
			 condition2.signal();
		}finally{
			lock.unlock();
		}
	}
}