MultiThread - Synchronized trong Java - Đồng bộ 3 threads - Sinh số ngẫu nhiên, bình phương, và chia hết

#Main.java

/*
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 */
package com.gokisoft.c2209i.lesson06.bt1102;

/**
 *
 * @author teacher
 */
public class Main {
    public static void main(String[] args) {
        SharedData sharedData = new SharedData();
        Thread1 t1 = new Thread1(sharedData);
        Thread2 t2 = new Thread2(sharedData);
        Thread3 t3 = new Thread3(sharedData);
        
        t1.start();
        t2.start();
        t3.start();
    }
}

#SharedData.java

/*
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package com.gokisoft.c2209i.lesson06.bt1102;

/**
 *
 * @author teacher
 */
public class SharedData {
    public static final int THREAD_1 = 1;
    public static final int THREAD_2 = 2;
    public static final int THREAD_3 = 3;
    
    int currThread = THREAD_1;
    
    int rad = 0;
    int total = 0;

    public SharedData() {
    }

    public int getRad() {
        return rad;
    }

    public void setRad(int rad) {
        this.rad = rad;
        this.total += rad;
    }
    
    public boolean isLive() {
        return total < 200;
    }

    public int getCurrThread() {
        return currThread;
    }

    public void setCurrThread(int currThread) {
        this.currThread = currThread;
    }
}

#Thread1.java

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package com.gokisoft.c2209i.lesson06.bt1102;

import java.util.Random;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author teacher
 */
public class Thread1 extends Thread {

    SharedData sharedData;

    public Thread1(SharedData sharedData) {
        this.sharedData = sharedData;
    }

    @Override
    public void run() {
        Random random = new Random();
        int rad;

        while (sharedData.isLive()) {
            synchronized (sharedData) {
                rad = random.nextInt(1, 100);
                System.out.println("T1: " + rad);
                sharedData.setRad(rad);
                
                //Xac dinh thread tiep theo chay la gi
                if(rad % 3 == 0) {
                    sharedData.setCurrThread(SharedData.THREAD_2);
                } else {
                    sharedData.setCurrThread(SharedData.THREAD_3);
                }
                
                sharedData.notifyAll();
                try {
                    while(sharedData.isLive() && sharedData.getCurrThread() != SharedData.THREAD_1) {
                        sharedData.wait();
                    }
                } catch (InterruptedException ex) {
                    Logger.getLogger(Thread1.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
        
        synchronized (sharedData) {
            sharedData.notifyAll();
        }
        
        System.out.println("T1 stop");
    }

}

#Thread2.java

/*
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 */
package com.gokisoft.c2209i.lesson06.bt1102;

import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author teacher
 */
public class Thread2 extends Thread {

    SharedData sharedData;

    public Thread2(SharedData sharedData) {
        this.sharedData = sharedData;
    }

    @Override
    public void run() {
        while (sharedData.isLive()) {
            synchronized (sharedData) {
                sharedData.notifyAll();
                try {
                    if(sharedData.isLive() && sharedData.getCurrThread() != SharedData.THREAD_2) {
                        sharedData.wait();
                    }
                } catch (InterruptedException ex) {
                    Logger.getLogger(Thread2.class.getName()).log(Level.SEVERE, null, ex);
                }
                
                int rad = sharedData.getRad();
                System.out.println("T2: " + (rad * rad));
                
                sharedData.setCurrThread(SharedData.THREAD_1);
            }
        }
        
        synchronized (sharedData) {
            sharedData.notifyAll();
        }
        
        System.out.println("T2 stop");
    }

}

#Thread3.java

/*
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 */
package com.gokisoft.c2209i.lesson06.bt1102;

import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author teacher
 */
public class Thread3 extends Thread {

    SharedData sharedData;

    public Thread3(SharedData sharedData) {
        this.sharedData = sharedData;
    }

    @Override
    public void run() {
        while (sharedData.isLive()) {
            synchronized (sharedData) {
                sharedData.notifyAll();
                try {
                    if(sharedData.isLive() && sharedData.getCurrThread() != SharedData.THREAD_3) {
                        sharedData.wait();
                    }
                } catch (InterruptedException ex) {
                    Logger.getLogger(Thread3.class.getName()).log(Level.SEVERE, null, ex);
                }
                
                int rad = sharedData.getRad();
                if (rad % 4 == 0) {
                    System.out.println("T3: Chia het cho 4");
                } else {
                    System.out.println("T3: Khong chia het cho 4");
                }
                
                sharedData.setCurrThread(SharedData.THREAD_1);
            }
        }
        
        synchronized (sharedData) {
            sharedData.notifyAll();
        }
        
        System.out.println("T3 stop");
    }

}