多線程交替打印示例

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;

/**
 * 可以實現指定的打印次數，和每次打印的個數，
 * 按線程順序進行交替打印，打印完之后會停止多線程
 * 思路：不同線程類實現不同的邏輯，通過並發包下的原子類來進行控制停止的時機，
 *　　　　　用condition 來進行控制不同線程之間的通信，用參數控制打印元素的個數和總共打印的輪數
 */
public class TestCondition {
    public int signal ;
    public ReentrantLock lock = new ReentrantLock();
    public Condition conditionA = lock.newCondition();
    public Condition conditionB = lock.newCondition();
    public Condition conditionC = lock.newCondition();
    public AtomicInteger shutdown = new AtomicInteger(5);
    public int printANum;
    public int printBNum;
    public int printCNum;
    public int printCount;
    public TestCondition(int printANum,int printBNum,int printCNum,int printCount){
        this.printANum = printANum;
        this.printBNum = printBNum;
        this.printCNum = printCNum;
        this.printCount = printCount;
    }
    public void  printA(){
        try {
            lock.lock();
            while (signal!=0 ){
                conditionA.await();
            }
            for (int i = 1; i<=printANum;i++){
                System.out.print("A");
            }
            signal++;
            conditionB.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }
    public void  printB(){
        try {
            lock.lock();
            while (signal!=1 ){
                conditionB.await();
            }
            for (int i = 1; i<=printBNum;i++){
                System.out.print("B");
            }
            signal++;
            conditionC.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }
    public void  printC(){
        try {
            lock.lock();
            if (signal!=2 ){
                conditionC.await();
            }
            for (int i = 1; i<=printCNum;i++){
                System.out.print("C");
            }
            signal = 0;
            conditionA.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    public static void main(String[] args) {
        TestCondition testCondition =
                new TestCondition(1,1,1,5);
        A a = new A(testCondition);
        B b = new B(testCondition);
        C c = new C(testCondition);

        new Thread(a).start();
        new Thread(b).start();
        new Thread(c).start();
    }
}

class  A implements Runnable{
    public TestCondition testCondition;
    public A (TestCondition testCondition){
        this.testCondition = testCondition;
    }
    public void run() {
        while (testCondition.shutdown.get()>0){
            testCondition.printA();
            testCondition.shutdown.decrementAndGet();
        }
    }
}

class  B implements Runnable {
    public TestCondition testCondition;
    public B (TestCondition testCondition){
        this.testCondition = testCondition;
    }
    public void run() {
        while (testCondition.shutdown.get()>0){
            testCondition.printB();
        }
    }

}
class  C implements Runnable {
    public TestCondition testCondition;
    public C (TestCondition testCondition){
        this.testCondition = testCondition;
    }
    public void run() {
        while (testCondition.shutdown.get()>0){
            testCondition.printC();
        }
    }
}