Sử dụng MultiThreading sinh ký tự a-zA-Z trong java

#Main.java

/*
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package com.gokisoft.bt1107;

/**
 *
 * @author teacher
 */
public class Main {
    public static void main(String[] args) {
        SharedData sharedData = new SharedData();
        
//        char c = sharedData.getRandomLowerCaseChar();
//        char C = sharedData.getUpperCaseChar();
//        
//        System.out.println(c + " - " + C);

        Thread1 t1 = new Thread1(sharedData);
        Thread2 t2 = new Thread2(sharedData);
        
        t1.start();
        t2.start();
    }
}

#SharedData.java

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package com.gokisoft.bt1107;

import java.util.Random;

/**
 *
 * @author teacher
 */
public class SharedData {
    char radC;
    int deltaTime = 0;
    
    public char getRandomLowerCaseChar() {
        int min = 'a';
        int max = 'z';
        int delta = max - min;
        Random random = new Random();
        
        int rad = random.nextInt(delta);
        
        int _radC = min + rad;
        
        radC = (char) _radC;
        
        return radC;
    }
    
    public char getUpperCaseChar() {
        int codea = 'a';
        int codeA = 'A';
        int delta = codea - codeA;
        
        return (char) (radC - delta);
    }
    
    public synchronized void addTime(int delta) {
        deltaTime += delta;
    }
    
    public boolean isLive() {
        return deltaTime <= 20;
    }
}

#Thread1.java

/*
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package com.gokisoft.bt1107;

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() {
        try {
            Thread.sleep(100);
        } catch (InterruptedException ex) {
            Logger.getLogger(Thread1.class.getName()).log(Level.SEVERE, null, ex);
        }
        
        synchronized (sharedData) {
            for (;sharedData.isLive();) {
                char c = sharedData.getRandomLowerCaseChar();
                System.out.println("T1 > " + c);
                
                sharedData.notifyAll();
                try {
                    sharedData.wait();
                } catch (InterruptedException ex) {
                    Logger.getLogger(Thread1.class.getName()).log(Level.SEVERE, null, ex);
                }
                
                try {
                    Thread.sleep(2000);
                    sharedData.addTime(2);
                } catch (InterruptedException ex) {
                    Logger.getLogger(Thread1.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
        
        System.out.println("T1 stop");
        synchronized(sharedData) {
            sharedData.notifyAll();
        }
    }
}

#Thread2.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
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 */
package com.gokisoft.bt1107;

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() {
        synchronized (sharedData) {
            for (;sharedData.isLive();) {
                sharedData.notifyAll();
                try {
                    sharedData.wait();
                } catch (InterruptedException ex) {
                    Logger.getLogger(Thread2.class.getName()).log(Level.SEVERE, null, ex);
                }
                
                char c = sharedData.getUpperCaseChar();
                System.out.println("T2 > " + c);
                
                try {
                    Thread.sleep(1000);
                    sharedData.addTime(1);
                } catch (InterruptedException ex) {
                    Logger.getLogger(Thread2.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
        
        System.out.println("T2 stop");
        synchronized(sharedData) {
            sharedData.notifyAll();
        }
    }
}