多线程按序交替打印

一、线程按序交替打印

效果展示：

A     1
A     2
A     3
A     4
A     5
B     1
B     2
B     3
B     4
B     5
C     1
C     2
C     3
C     4
C     5

代码实现：

package juc;

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

public class AlternativePrint {
    private ReentrantLock lock = new ReentrantLock();
    private Condition conditionA = lock.newCondition();
    private Condition conditionB = lock.newCondition();
    private Condition conditionC = lock.newCondition();

    private int number = 1;

    public void loopA(){
        lock.lock();
        try {
            if (number != 1){
                conditionA.await();
            }

            for (int i = 1; i <= 5; i++){
                System.out.println(Thread.currentThread().getName() + "     " + i);
            }

            number = 2;
            conditionB.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    public void loopB(){
        lock.lock();
        try {
            if (number != 2){
                conditionB.await();
            }

            for (int i = 1; i <= 5; i++){
                System.out.println(Thread.currentThread().getName() + "     " + i);
            }

            number = 3;
            conditionC.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    public void loopC(){
        lock.lock();
        try {
            if (number != 3){
                conditionC.await();
            }

            for (int i = 1; i <= 5; i++){
                System.out.println(Thread.currentThread().getName() + "     " + i);
            }

            number = 1;
            conditionA.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            System.out.println("--------------------------------------------------");
            lock.unlock();
        }
    }

    public static void main(String[] args) {

        final AlternativePrint alternativePrint = new AlternativePrint();

        new Thread("A"){
            @Override
            public void run() {
                for (int i= 0; i < 20; i++)
                    alternativePrint.loopA();
            }
        }.start();

        new Thread("B"){
            @Override
            public void run() {
                for (int i= 0; i < 20; i++)
                    alternativePrint.loopB();
            }
        }.start();

        new Thread("C"){
            @Override
            public void run() {
                for (int i= 0; i < 20; i++)
                    alternativePrint.loopC();
            }
        }.start();
    }
}

二、多线程交替打印10次abc实例

效果展示：

A     1
B     1
C     1
-----------------------------------------------------------------
A     1
B     1
C     1
-----------------------------------------------------------------

代码实现：

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

public class AlternativePrint {
    private ReentrantLock lock = new ReentrantLock();
    private Condition conditionA = lock.newCondition();
    private Condition conditionB = lock.newCondition();
    private Condition conditionC = lock.newCondition();

    private int number = 1;

    public void loopA(){
        lock.lock();
        try {
            if (number != 1){
                conditionA.await();
            }

            for (int i = 1; i <= 1; i++){
                System.out.println(Thread.currentThread().getName() + "     " + i);
            }

            number = 2;
            conditionB.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    public void loopB(){
        lock.lock();
        try {
            if (number != 2){
                conditionB.await();
            }

            for (int i = 1; i <= 1; i++){
                System.out.println(Thread.currentThread().getName() + "     " + i);
            }

            number = 3;
            conditionC.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    public void loopC(){
        lock.lock();
        try {
            if (number != 3){
                conditionC.await();
            }

            for (int i = 1; i <= 1; i++){
                System.out.println(Thread.currentThread().getName() + "     " + i);
            }

            number = 1;
            conditionA.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            System.out.println("-----------------------------------------------");
            lock.unlock();
        }
    }

    public static void main(String[] args) {

        final AlternativePrint alternativePrint = new AlternativePrint();

        new Thread("A"){
            @Override
            public void run() {
                for (int i= 0; i < 20; i++)
                    alternativePrint.loopA();
            }
        }.start();

        new Thread("B"){
            @Override
            public void run() {
                for (int i= 0; i < 20; i++)
                    alternativePrint.loopB();
            }
        }.start();

        new Thread("C"){
            @Override
            public void run() {
                for (int i= 0; i < 20; i++)
                    alternativePrint.loopC();
            }
        }.start();

    }
}

原文地址：https://www.cnblogs.com/ch-forever/p/10293741.html