技術標籤：Java

多執行緒練習：

package multithreading;

// 銀行有一個賬戶
// 有兩個賬戶分表向同一個賬戶存3000元，每次1000，存3次。每次存完列印賬戶餘額
public class MultiThreading {
    public static void main(String[] args) {
        Account account = new Account();
        Thread account1 = new Thread(account);
        Thread account2 = new Thread(account)
 
;
        account1.start();
        account2.start();


    }
}

class Account implements Runnable{
    private int balance = 0;
    public void setBalance(){
        balance += 1000;
        getBalance();
    }
    public void getBalance(){
        System.out.println("balance is: "+balance);
    }
 

    public void run(){
        while(balance<3000){
            setBalance();
        }
    }
}

由於沒有增加同步，所以執行會出現執行緒安全問題，以下是每次存完錢顯示的餘額：

同步方式一：synchronized()

package multithreading;

// 銀行有一個賬戶
// 有兩個賬戶分表向同一個賬戶存3000元，每次1000，存3次。每次存完列印賬戶餘額
public class MultiThreading {
    public static void main(String[] args)
 
 {
        Account account = new Account();
        Thread account1 = new Thread(account);
        Thread account2 = new Thread(account);
        account1.start();
        account2.start();


    }
}
// 同步方式一： synchronized:
class Account implements Runnable{
    private int balance = 0;
    public void setBalance(){
        balance += 1000;
        getBalance();
    }
    public void getBalance(){
        System.out.println("balance is: "+balance);
    }
    public synchronized void run(){
        while(balance<3000){
            setBalance();
        }
    }
}

同步方式二：Lock

package multithreading;

import java.util.concurrent.locks.ReentrantLock;

// 銀行有一個賬戶
// 有兩個賬戶分表向同一個賬戶存3000元，每次1000，存3次。每次存完列印賬戶餘額
public class MultiThreading {
    public static void main(String[] args) {
        Account account = new Account();
        Thread account1 = new Thread(account);
        Thread account2 = new Thread(account);
        account1.start();
        account2.start();


    }
}
// 同步方式二： Lock:
class Account implements Runnable{
    private int balance = 0;
    public void setBalance(){
        balance += 1000;
        getBalance();
    }
    public void getBalance(){
        System.out.println("balance is: "+balance);
    }
    static ReentrantLock lock = new ReentrantLock();
    public void run(){
        lock.lock();
        while(balance<3000){
            setBalance();
        }
        lock.unlock();
    }
}