首页 > 代码库 > 添加二级缓存_配置及使用

添加二级缓存_配置及使用

项目添加二级缓存
1、需要引入三个jar包
在hibernate下能找到
hibernate-distribution-3.5.6-Final\lib\optional\ehcache\ehcache-1.5.0.jar
在srping下能找到
..\lib\concurrent\backport-util-concurrent.jar
..\lib\jakarta-commons\commons-logging.jar
2、在hibernate.cfg.xml中配置
(1)开启二级缓存:
<!-- 开启二级缓存 -->
<property name="hibernate.cache.use_second_level_cache">true</property>
<!-- 配置二级缓存的供应商 -->
<property name="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider</property>
<!-- 启动二级缓存的查询缓存 -->
<property name="hibernate.cache.use_query_cache">true</property>
(2)添加类级别的二级缓存:
<!-- 配置类级别的二级缓存 -->
<class-cache class="cn.itcast.elec.domain.ElecSystemDDL" usage="read-write"/>
3、测试二级缓存:
在junit包下进行测试,TestHibernateCache.java进行测试:
public class TestHibernateCache {
@Test
public void testCache(){
Configuration configuration = new Configuration();
configuration.configure();
SessionFactory sf = configuration.buildSessionFactory();
Session s = sf.openSession();
Transaction tr = s.beginTransaction();

Query query = s.createQuery("from ElecSystemDDL");
//使用查询缓存
query.setCacheable(true);
query.list();//产生select语句

tr.commit();
s.close();
////////////////////////////////////////////////////////////////////
s = sf.openSession();
tr = s.beginTransaction();

Query query1 = s.createQuery("from ElecSystemDDL");
//使用查询缓存
query1.setCacheable(true);
query1.list();//?

tr.commit();
s.close();

}
}
4、在项目中添加二级缓存:
在CommonDaoImpl中添加方法
/**使用二级缓存,提高系统的检索性能*/
public List<T> findCollectionByConditionNoPageWithCache(String condition,
final Object[] params, LinkedHashMap<String, String> orderby) {
/**
* SELECT * FROM elec_text o WHERE 1=1 #DAO层封装
AND o.textName LIKE ? #Service层封装
AND o.textRemark LIKE ? #Service层封装
ORDER BY o.textDate ASC,o.textName DESC #Service层封装
*/
//定义Hql语句
String hql = "from " + entityClass.getSimpleName() + " o where 1=1";
String orderHql = this.orderByHql(orderby);
final String finalHql = hql + condition + orderHql;
//执行hql语句
//方法一:
//List<T> list = this.getHibernateTemplate().find(hql,params);
//方法二:
List<T> list = (List<T>) this.getHibernateTemplate().execute(new HibernateCallback(){
public Object doInHibernate(Session session)
throws HibernateException, SQLException {
Query query = session.createQuery(finalHql);
for(int i=0;params!=null && i<params.length;i++){
query.setParameter(i, params[i]);
}
//启用二级缓存存储数据
query.setCacheable(true);
return query.list();
}
});
return list;
}

 

 

 

 

 

使用实例

/**使用二级缓存,提高系统的检索性能*/
public List<T> findCollectionByConditionNoPageWithCache(String condition,
final Object[] params, LinkedHashMap<String, String> orderby) {
/**
* SELECT * FROM elec_text o WHERE 1=1 #DAO层封装
AND o.textName LIKE ? #Service层封装
AND o.textRemark LIKE ? #Service层封装
ORDER BY o.textDate ASC,o.textName DESC #Service层封装
*/
//定义Hql语句
String hql = "from " + entityClass.getSimpleName() + " o where 1=1";
String orderHql = this.orderByHql(orderby);
final String finalHql = hql + condition + orderHql;
//执行hql语句
//方法一:
//List<T> list = this.getHibernateTemplate().find(hql,params);
//方法二:
List<T> list = (List<T>) this.getHibernateTemplate().execute(new HibernateCallback(){
public Object doInHibernate(Session session)
throws HibernateException, SQLException {
Query query = session.createQuery(finalHql);
for(int i=0;params!=null && i<params.length;i++){
query.setParameter(i, params[i]);
}
//启用二级缓存存储数据
query.setCacheable(true);
return query.list();
}
});
return list;
}