Balk Pattern

最新推荐文章于 2017-11-30 19:20:25 发布

翻译最新推荐文章于 2017-11-30 19:20:25 发布 · 368 阅读

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本文探讨了如何在多线程环境下实现数据的并发管理与实时更新，通过使用同步机制确保数据的一致性和完整性。

package com.albert.thread;

import java.util.LinkedList;
import java.util.Random;
class Data
{
   //保存时的文件名
   private final String fileName;
   //数据的内容
   private String content;
   //修改后的内容还没保存,为true
   private boolean changed;

   public Data(String fileName,String content)
   {
       this.fileName = fileName;
       this.content = content;
       this.changed = true;
   }
   //修改数据内容
   public synchronized void change(String content)
   {
       this.content = content;
       this.changed = true;
   }
   //若有数据修改 ,就保存在文件里
   public synchronized void save()
   {
       if(!this.changed)
       {
           return;
       }
       doSave();
       this.changed = false;
   }
   private void doSave() {

       System.out.println(Thread.currentThread().getName()+" calls doSave content="+content);
       System.out.println("内容写入文件:"+this.fileName);
   }
}

class SaverThread extends Thread
{
   private Data data;
   public SaverThread(String name,Data data)
   {
       super(name);
       this.data = data;
   }
   public void run()
   {
       while(true)
       {
           //保存数据
           data.save();
           try {
               Thread.sleep(1000);
           } catch (InterruptedException e) {
               e.printStackTrace();
           }
       }
   }
}
class ChangerThread extends Thread
{
   private Data data;
   private Random random = new Random();
   public ChangerThread(String name,Data data)
   {
       super(name);
       this.data = data;
   }
   public void run()
   {
       for(int i=0;true;i++)
       {
           data.change("No."+i);
           try {
               Thread.sleep(random.nextInt(1000));
           } catch (InterruptedException e) {
               e.printStackTrace();
           }
           //明确的要求存档
           data.save();
       }
   }
}

public class MyThread {

   private static final long CALL_COUNT=100000L;

   /**
   * @param args
   */
   public static void main(String[] args) {
           Data data = new Data("a.txt","(empty)");
           new ChangerThread("ChangerThread",data).start();
           new SaverThread("SaverThread",data).start();

   }
}