Java利用多线程做的一些习题（一）

悠悠 2023-06-07 05:40 23阅读 0赞

# 题目 #

1、用多线程程序设计方式模拟铁路售票，一共100张，通过四个窗口卖完。分别用实现多线程程序设计的两种方式完成。

# 效果 #

1.多线程方式效果

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzNTc2MDI4_size_16_color_FFFFFF_t_70]

2.线程池方式效果

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzNTc2MDI4_size_16_color_FFFFFF_t_70 1]

# 代码 #

1.多线程方式

package P1;
    
    import java.util.concurrent.ExecutorService;
    import java.util.concurrent.Executors;
    import java.util.concurrent.locks.Condition;
    import java.util.concurrent.locks.Lock;
    import java.util.concurrent.locks.ReentrantLock;
    
    import static java.lang.Thread.currentThread;
    import static java.lang.Thread.sleep;
    
    public class thread1 {
        
    
    
        public static void main(String[] args){
        
    
            Runnable window1=new Sold(100);
            Runnable window2=new Sold(100);
            Runnable window3=new Sold(100);
            Runnable window4=new Sold(100);
    
            Thread thread1=new Thread(window1);
            Thread thread2=new Thread(window2);
            Thread thread3=new Thread(window3);
            Thread thread4=new Thread(window4);
    
            thread1.start();
            thread2.start();
            thread3.start();
            thread4.start();
    
        }
    }
    class Sold implements Runnable{
        
        private static Lock lock = new ReentrantLock();
        private static Condition newSold=lock.newCondition();
    
        private static  int total;//火车票总数
        public Sold(int total) {
        
            this.total = total;
        }
    
        @Override
        public void run() {
        
    
            try {
        
                rest();
                Thread.sleep(1000);
            } catch (InterruptedException e) {
        
                e.printStackTrace();
            }
        }
    
        private   void rest() {
        
            lock.lock();
                try {
        
                    while(total!=0){
        
                         Thread.sleep(5);
                        total-=1;
                        System.out.println("还剩"+total+"张票");
                   }
    
                } catch (InterruptedException e) {
        
                    e.printStackTrace();
                }finally {
        
                    lock.unlock();
    
                }
            }
    
        }

2.线程池方式效果

package P1;
    
    import java.util.concurrent.ExecutorService;
    import java.util.concurrent.Executors;
    import java.util.concurrent.locks.Condition;
    import java.util.concurrent.locks.Lock;
    import java.util.concurrent.locks.ReentrantLock;
    
    import static java.lang.Thread.currentThread;
    import static java.lang.Thread.sleep;
    
    public class thread1 {
        
    
    
        public static void main(String[] args){
        
            //创建三个任务
            ExecutorService executor= Executors.newFixedThreadPool(4);
    
    
            executor.execute(new Sold(100));
            executor.execute(new Sold(100));
            executor.execute(new Sold(100));
            executor.execute(new Sold(100));
    
            executor.shutdown();
    
        }
    }
    class Sold implements Runnable{
        
        private static Lock lock = new ReentrantLock();
        private static Condition newSold=lock.newCondition();
    
        private static  int total;//火车票总数
        public Sold(int total) {
        
            this.total = total;
        }
    
        @Override
        public void run() {
        
    
            try {
        
                rest();
                Thread.sleep(1000);
            } catch (InterruptedException e) {
        
                e.printStackTrace();
            }
        }
    
        private synchronized void rest() {
        
            lock.lock();
                try {
        
                    while(total!=0){
        
                         Thread.sleep(5);
                        total-=1;
                        System.out.println("还剩"+total+"张票");
                   }
    
                } catch (InterruptedException e) {
        
                    e.printStackTrace();
                }finally {
        
                    lock.unlock();
    
                }
            }
    
        }

# 思路 #

因为多线程的并行是交替运行的，所以会导致结果出现的顺序不一致，所以使用加锁的方式迫使线程一定要等到当前线程结束后才能运行。

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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzNTc2MDI4_size_16_color_FFFFFF_t_70 1]: /images/20230601/b952c3db9ce44136a0c2a5933352ca11.png