Mybatis 结合ehcache

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Mybatis 结合ehcache5

刚开始看mybatis ，在结合缓存的时候，遇到个问题，按照官方文档上面配置的ehcache配置，相应的jar包也加入进来，但是无路如何都没有成功

数据每次都是从数据库里面读取的，命中要么为0 ，要么直接miss

不知道啥原因，谁帮忙看下
代码如下先看debug 信息

2012-07-17 12:47:47,124 [main] DEBUG [net.sf.ehcache.store.MemoryStore] - Initialized net.sf.ehcache.store.MemoryStore for com.ztiny.mybatis.dao.impl
2012-07-17 12:47:47,126 [main] DEBUG [net.sf.ehcache.Cache] - Initialised cache: com.ztiny.mybatis.dao.impl
2012-07-17 12:47:47,189 [main] DEBUG [net.sf.ehcache.Cache] - com.test.mybatis.dao.implCache: com.ztiny.mybatis.dao.implMemoryStore miss for 139696085:3585427282:com.ztiny.mybatis.dao.impl.selectAll:0:2147483647:select name as username ,age from employee
2012-07-17 12:47:47,189 [main] DEBUG [net.sf.ehcache.Cache] - com.test.mybatis.dao.impl cache - Miss
2012-07-17 12:47:47,391 [main] DEBUG [com.test.mybatis.dao.impl.selectAll] - ooo Using Connection [com.mysql.jdbc.Connection@6abde0]
2012-07-17 12:47:47,392 [main] DEBUG [com.test.mybatis.dao.impl.selectAll] - ==> Preparing: select name as username ,age from employee
2012-07-17 12:47:47,419 [main] DEBUG [com.test.mybatis.dao.impl.selectAll] - ==> Parameters:
2012-07-17 12:47:47,666 [main] DEBUG [net.sf.ehcache.Cache] - com.test.mybatis.dao.implCache: com.test.mybatis.dao.implMemoryStore miss for 139696085:3585427282:com.ztiny.mybatis.dao.impl.selectAll:0:2147483647:select name as username ,age from employee
2012-07-17 12:47:47,666 [main] DEBUG [net.sf.ehcache.Cache] - com.test.mybatis.dao.impl cache - Miss
2012-07-17 12:47:47,674 [main] DEBUG [com.test.mybatis.dao.impl.selectAll] - ooo Using Connection [com.mysql.jdbc.Connection@9f45f4]
2012-07-17 12:47:47,674 [main] DEBUG [com.test.mybatis.dao.impl.selectAll] - ==> Preparing: select name as username ,age from employee
2012-07-17 12:47:47,674 [main] DEBUG [com.test.mybatis.dao.impl.selectAll] - ==> Parameters:

从这个debug信息可以看到，打开了两次数据库连接，cache 没起作用
下面看下我的ehcache。xml配置

<?xml version="1.0" encoding="UTF-8"?>  
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
    xsi:noNamespaceSchemaLocation="../bin/ehcache.xsd">  
    <defaultCache overflowToDisk="true" eternal="true"/>  
    <diskStore path="f:/test/cache" />  
</ehcache>

employee.xml

mapper namespace="com.test.mybatis.dao.impl">  
    <cache type="org.mybatis.caches.ehcache.LoggingEhcache"/>  
    
    <select id="selectAll"  resultType="com.test.entity.Employee">  
        select name as username ,age from employee   
    </select>

测试代码

public List<Employee> selectList() {  
        return super.getSession(false).selectList("selectAll");  
    }  
      
    public static void main(String args[]) throws Exception{  
        EmployeeDaoImpl emplDao = new EmployeeDaoImpl();  
        emplDao.selectList();//第一次  
        emplDao.selectList();//第二次，应该从缓存里面读取  
    }

mybatis 源码：

BoundSql boundSql = ms.getBoundSql(parameterObject);  
   //根据规则创建缓存对应的键，因为查询相同，所以第二次这个还是这个键，没错  
    CacheKey key = createCacheKey(ms, parameterObject, rowBounds, boundSql);  
   //在执行查询  
    return query(ms, parameterObject, rowBounds, resultHandler, key, boundSql); 

public <E> List<E> query(MappedStatement ms, Object parameterObject, RowBounds rowBounds, ResultHandler resultHandler, CacheKey key, BoundSql boundSql) throws SQLException {  
    Cache cache = ms.getCache();  
    if (cache != null) {  
      flushCacheIfRequired(ms);  
      if (ms.isUseCache() && resultHandler == null) {   
        ensureNoOutParams(ms, key, parameterObject, boundSql);  
        if (!dirty) {  
          cache.getReadWriteLock().readLock().lock();  
          try {  
            @SuppressWarnings("unchecked")  
            List<E> cachedList = (List<E>) cache.getObject(key);  
            if (cachedList != null) return cachedList;  
          } finally {  
            cache.getReadWriteLock().readLock().unlock();  
          }  
        }  
        List<E> list = delegate.<E> query(ms, parameterObject, rowBounds, resultHandler, key, boundSql);  
//因为第一次没有缓存，所以创建了缓存然后再把数据放入缓存里面，但是这里有个问题，这个缓存每次都是重新创建的，大家可以去debug 看看，不知是我配置错了，还是怎么的，反正进入到这个方法里面，每次都是空的，看下面代码  
        tcm.putObject(cache, key, list); // issue #578. Query must be not synchronized to prevent deadlocks  
        return list;  
      }  
    }  
//这里老是空对象，每次都是从新创建   
    TransactionalCache txCache = transactionalCaches.get(cache);  
    if (txCache == null) {  
      txCache = new TransactionalCache(cache);  
      transactionalCaches.put(cache, txCache);  
    }

问题补充： ps：做个之前最好能在本地测下，成功了，用真实数据给我看下，因为网络上很多都是简单的配置，我不知道具体有没有成功，我这里是没成功，看坛子里面有个有为同学用memcached 测试成功了，
membercached 我没测试，但是这里的ehcache 就是不行谢谢

MyBatis