Java synchronized demo (Producer-Consumer model), 同步化範例.

package thread;

public class SynchronizeDemo {

    public static void main(String[] args) {
        Account acnt = new Account();
        Thread prod = new Thread(new Producer(acnt));
        Thread con = new Thread(new Consumer(acnt));
        Thread mon = new Thread(new Monitor(acnt));
        prod.start();
        con.start();
        mon.start();
    }

}

class Account {

    int sum = 50;

    public synchronized void withDraw() {
        try {
            if (sum <= 0) {
                this.wait();
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        if (sum >= 10) {
            sum -= 10;
            System.out.println("Withdraw 10");
        } else {
            System.out.println("Withdraw " + sum);
            sum -= sum;
        }
    }

    public synchronized void Deposit() {
        sum++;
        System.out.println("Deposit 1");
        this.notify();
    }

    public synchronized void printBalance() {
        if (sum <= 0) {
            System.out.println("No money now.");
        } else {
            System.out.println("Balance :" + sum);
        }
    }

}

class Producer implements Runnable {
    Account account;

    Producer(Account act) {
        this.account = act;
    }

    public void run() {
        while (true) {
            account.Deposit();
            try {
                Thread.sleep(6000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }
    }
}

class Consumer implements Runnable {
    Account account;

    Consumer(Account act) {
        this.account = act;
    }

    public void run() {
        while (true) {
            account.withDraw();
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }
    }
}

class Monitor implements Runnable {
    Account account;

    Monitor(Account act) {
        this.account = act;
    }

    public void run() {
        while (true) {
            account.printBalance();
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }
    }
}