mybatis 自定义缓存 cache

缓存不管哪个框架都是显得特别的重要，今天自己测试实现了mybatis自定义缓存，从而理解mybatis缓存的工作原理。

首先缓存类要实现Cache接口：具体实现如下package com.ibatis.blog;
package com.ibatis.cache;

import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import org.apache.ibatis.cache.Cache;

public class MyCache implements Cache
{
   private ReadWriteLock lock = new ReentrantReadWriteLock();
   private ConcurrentHashMap<Object, Object> cache = new ConcurrentHashMap<Object, Object>();
   private String id;

   public MyCache()
   {
   }
/ /这个构造方法必须有
   public MyCache(String id)
   {
       this.id = id;
   }

   public void clear()
   {
       cache.clear();
   }

   public String getId()
   {
       System.out.println("getId-->" + id);
       return id;
   }

   public Object getObject(Object key)
   {
       System.out.println("getObject---key:" + key);
       return cache.get(key);
   }

   public ReadWriteLock getReadWriteLock()
   {
//       System.out.println("getReadWriteLock");
       return lock;
   }

   public synchronized int getSize()
   {
       System.out.println("getsize");
       return cache.size();
   }

   public void putObject(Object key, Object value)
   {
       // System.out.println("putObject--key:" + key);
       // System.out.println("putObject--value:" + value);
       cache.put(key, value);
   }

   public Object removeObject(Object key)
   {
       System.out.println("remove:" + key);
       return cache.remove(key);
   }

}

需要在配置文件中添加：

进行测试：进行两次相同的查询：

@Test
   public void testSelectAll()
   {
       List<Article> result = service.findAll(null);
       for (Article a : result)
       {
           System.out.println(a);
       }
       System.out.println("-----------");
       List<Article> result1 = service.findAll(null);
       for (Article a : result1)
       {
           System.out.println(a);
       }
   }

产生的结果如下：

getId-->article
getObject---key:-395398842:3059602323:article.article_selectAll:0:2147483647:select * from
       article
getObject---key:-1263983414:-596172894:article.selectUser:0:2147483647:select * from user
       where
       id=?:1
getObject---key:-1263983414:-596172894:article.selectUser:0:2147483647:select * from user
       where
       id=?:1
Article [id=1, name=firstArticle, time=2013-11-3 0:00:00, user=User [article=null, id=1, name=d, sex=1]]
Article [id=2, name=secondArticle, time=2013-11-3 0:00:00, user=User [article=null, id=1, name=d, sex=1]]
-----------
getObject---key:-395398842:3059602323:article.article_selectAll:0:2147483647:select * from
       article
Article [id=1, name=firstArticle, time=2013-11-3 0:00:00, user=User [article=null, id=1, name=d, sex=1]]
Article [id=2, name=secondArticle, time=2013-11-3 0:00:00, user=User [article=null, id=1, name=d, sex=1]]

缓存设置成功，第二次查询的时候直接从缓存中查询了！

mybatis 自定义缓存 cache

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