Bài toán đa luồng (MultiThreading in java) đọc File trong Java

#Main.java

/*
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 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
package com.gokisoft.lesson04;

import java.io.BufferedWriter;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Random;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author teacher
 */
public class Main {
    public static void main(String[] args) {
        //createDataFile();
        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();
    }
    
    /**
     * Cau 1
     */
    static void createDataFile() {
        FileWriter fileWriter = null;
        BufferedWriter bufferedWriter = null;
        
        Random random = new Random();
        int n;
        
        try {
            fileWriter = new FileWriter("number.txt");
            bufferedWriter = new BufferedWriter(fileWriter);
            
            n = random.nextInt(10, 100);
            bufferedWriter.write(n+"\n");
            
            for (int i = 0; i < n; i++) {
                int num = random.nextInt(1, 500);
                bufferedWriter.write(num+"\n");
            }
        } catch (IOException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            if(bufferedWriter != null) {
                try {
                    bufferedWriter.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
            if(fileWriter != null) {
                try {
                    fileWriter.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
        //Ends
    }
}

#SharedData.java

/*
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 */
package com.gokisoft.lesson04;

/**
 *
 * @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 num;
    boolean live;
    int currentThread;

    public SharedData() {
        num = 0;
        live = true;
        currentThread = THREAD_1;
    }

    public boolean isLive() {
        return live;
    }

    public void setLive(boolean live) {
        this.live = live;
    }

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }

    public int getCurrentThread() {
        return currentThread;
    }

    public void setCurrentThread(int currentThread) {
        this.currentThread = currentThread;
    }
}

#Thread1.java

/*
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 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
package com.gokisoft.lesson04;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
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() {
        synchronized (sharedData) {
            FileReader fileReader = null;
            BufferedReader bufferedReader = null;

            try {
                fileReader = new FileReader("number.txt");
                bufferedReader = new BufferedReader(fileReader);

                //Remove first line
                bufferedReader.readLine();
                String line;

                while ((line = bufferedReader.readLine()) != null) {
                    if (!line.isEmpty()) {
                        //Du lieu chuan
                        int num = Integer.parseInt(line.trim());
                        System.out.println(num);
                        sharedData.setNum(num);
                        if (num % 2 == 0) {
                            //Chuyen sang Thread 2
                            sharedData.setCurrentThread(SharedData.THREAD_2);
                        } else {
                            //Chuyen sang Thread 3
                            sharedData.setCurrentThread(SharedData.THREAD_3);
                        }
                        
                        sharedData.notifyAll();
                        try {
                            while(sharedData.isLive() && sharedData.getCurrentThread() != SharedData.THREAD_1) {
                                sharedData.wait();
                            }
                        } catch (InterruptedException ex) {
                            Logger.getLogger(Thread1.class.getName()).log(Level.SEVERE, null, ex);
                        }
                        try {
                            Thread.sleep(1000);
                        } catch (InterruptedException ex) {
                            Logger.getLogger(Thread1.class.getName()).log(Level.SEVERE, null, ex);
                        }
                    }
                }
            } catch (FileNotFoundException ex) {
                Logger.getLogger(Thread1.class.getName()).log(Level.SEVERE, null, ex);
            } catch (IOException ex) {
                Logger.getLogger(Thread1.class.getName()).log(Level.SEVERE, null, ex);
            } finally {
                if (bufferedReader != null) {
                    try {
                        bufferedReader.close();
                    } catch (IOException ex) {
                        Logger.getLogger(Thread1.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }
                if (fileReader != null) {
                    try {
                        fileReader.close();
                    } catch (IOException ex) {
                        Logger.getLogger(Thread1.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }
                //Thong bao toi Thread khac -> STOP
                sharedData.setLive(false);
                
                sharedData.notifyAll();
            }
        }

        //Ends
        System.out.println("T1 stop");
    }

}

#Thread2.java

/*
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 */
package com.gokisoft.lesson04;

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) {
            while (sharedData.isLive()) {
                sharedData.notifyAll();
                try {
                    while (sharedData.isLive() && sharedData.getCurrentThread() != SharedData.THREAD_2) {
                        sharedData.wait();
                    }
                    if(!sharedData.isLive()) {
                        break;
                    }
                } catch (InterruptedException ex) {
                    Logger.getLogger(Thread2.class.getName()).log(Level.SEVERE, null, ex);
                }

                int num = sharedData.getNum();
                System.out.print("\nT2: ");
                for (int i = 1; i <= num; i++) {
                    if (num % i == 0) {
                        System.out.print(i + ",");
                    }
                }
                System.out.println("");
                //Chuyen sang Thread 1
                sharedData.setCurrentThread(SharedData.THREAD_1);
            }

            sharedData.notifyAll();
        }

        System.out.println("T2 stop");
    }

}

#Thread3.java

/*
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 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
package com.gokisoft.lesson04;

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() {
        synchronized (sharedData) {
            while (sharedData.isLive()) {
                sharedData.notifyAll();
                try {
                    while (sharedData.isLive() && sharedData.getCurrentThread() != SharedData.THREAD_3) {
                        sharedData.wait();
                    }
                    if(!sharedData.isLive()) {
                        break;
                    }
                } catch (InterruptedException ex) {
                    Logger.getLogger(Thread3.class.getName()).log(Level.SEVERE, null, ex);
                }

                int num = sharedData.getNum();
                System.out.println("T3: " + num * num);
                //Chuyen Thread1 chay
                sharedData.setCurrentThread(SharedData.THREAD_1);
            }

            sharedData.notifyAll();
        }
        System.out.println("T3 stop");
    }

}