mybatis缓存之整合第三方缓存工具ehcache

1、加入以下依赖包

2、配置ehcache.xml

<?xml version="1.0" encoding="UTF-8"?>
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:noNamespaceSchemaLocation="../config/ehcache.xsd">
 <!-- 磁盘保存路径 -->
 <diskStore path="D:\44\ehcache" />

 <defaultCache
   maxElementsInMemory="10000"
   maxElementsOnDisk="10000000"
   eternal="false"
   overflowToDisk="true"
   timeToIdleSeconds="120"
   timeToLiveSeconds="120"
   diskExpiryThreadIntervalSeconds="120"
   memoryStoreEvictionPolicy="LRU">
 </defaultCache>
</ehcache>

<!--
属性说明：
l diskStore：指定数据在磁盘中的存储位置。
l defaultCache：当借助CacheManager.add("demoCache")创建Cache时，EhCache便会采用<defalutCache/>指定的的管理策略

以下属性是必须的：
l maxElementsInMemory - 在内存中缓存的element的最大数目
l maxElementsOnDisk - 在磁盘上缓存的element的最大数目，若是0表示无穷大
l eternal - 设定缓存的elements是否永远不过期。如果为true，则缓存的数据始终有效，如果为false那么还要根据timeToIdleSeconds，timeToLiveSeconds判断
l overflowToDisk - 设定当内存缓存溢出的时候是否将过期的element缓存到磁盘上

以下属性是可选的：
l timeToIdleSeconds - 当缓存在EhCache中的数据前后两次访问的时间超过timeToIdleSeconds的属性取值时，这些数据便会删除，默认值是0,也就是可闲置时间无穷大
l timeToLiveSeconds - 缓存element的有效生命期，默认是0.,也就是element存活时间无穷大
 diskSpoolBufferSizeMB 这个参数设置DiskStore(磁盘缓存)的缓存区大小.默认是30MB.每个Cache都应该有自己的一个缓冲区.
l diskPersistent - 在VM重启的时候是否启用磁盘保存EhCache中的数据，默认是false。
l diskExpiryThreadIntervalSeconds - 磁盘缓存的清理线程运行间隔，默认是120秒。每个120s，相应的线程会进行一次EhCache中数据的清理工作
l memoryStoreEvictionPolicy - 当内存缓存达到最大，有新的element加入的时候， 移除缓存中element的策略。默认是LRU（最近最少使用），可选的有LFU（最不常使用）和FIFO（先进先出）
 -->

3、在mapper.xml中使用

<mapper namespace="com.gong.mybatis.dao.EmployeeMapper">
    <cache type="org.mybatis.caches.ehcache.EhcacheCache"></cache>
    ......
</mapper>

4、也可以在其它mapper.xml中引用配置好缓存的mapper

<mapper namespace="com.gong.mybatis.dao.DepartmentMapper">
    <cache-ref namespace="com.gong.mybatis.dao.EmployeeMapper"/>
    ......
</mapper>

最后进行测试二级缓存：

package com.gong.mybatis.test;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;

import com.gong.mybatis.bean.Department;
import com.gong.mybatis.bean.Employee;
import com.gong.mybatis.dao.EmployeeMapper;
import com.gong.mybatis.mapper.EmployeeMapperDynamicSql;

public class TestMybatis4 {

    public SqlSessionFactory getSqlSessionFactory() throws IOException {
        String resource = "mybatis-config.xml";
        InputStream is = Resources.getResourceAsStream(resource);
        return new SqlSessionFactoryBuilder().build(is);
    }

    @Test
    public void test() throws IOException {
        SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();
        SqlSession openSession = sqlSessionFactory.openSession();
        SqlSession openSession2 = sqlSessionFactory.openSession();

        try {
            EmployeeMapper mapper = openSession.getMapper(EmployeeMapper.class);
            EmployeeMapper mapper2 = openSession2.getMapper(EmployeeMapper.class);
            Employee em = mapper.getEmpById(1);
            System.out.println(em);
            openSession.close();
            Employee em2 = mapper2.getEmpById(1);
            System.out.println(em2);
            openSession.close();
        } finally {
            // TODO: handle finally clause

        }

    }

}

输出：

DEBUG 01-22 11:31:12,291 Configuring ehcache from ehcache.xml found in the classpath: file:/F:/ssmwork/mybatis/bin/ehcache.xml  (ConfigurationFactory.java:132)
DEBUG 01-22 11:31:12,307 Configuring ehcache from URL: file:/F:/ssmwork/mybatis/bin/ehcache.xml  (ConfigurationFactory.java:98)
DEBUG 01-22 11:31:12,307 Configuring ehcache from InputStream  (ConfigurationFactory.java:150)
DEBUG 01-22 11:31:12,417 Ignoring ehcache attribute xmlns:xsi  (BeanHandler.java:271)
DEBUG 01-22 11:31:12,417 Ignoring ehcache attribute xsi:noNamespaceSchemaLocation  (BeanHandler.java:271)
DEBUG 01-22 11:31:12,417 Disk Store Path: D:\44\ehcache  (DiskStoreConfiguration.java:141)
DEBUG 01-22 11:31:12,448 Creating new CacheManager with default config  (CacheManager.java:1036)
DEBUG 01-22 11:31:12,464 propertiesString is null.  (PropertyUtil.java:88)
DEBUG 01-22 11:31:12,479 No CacheManagerEventListenerFactory class specified. Skipping...  (ConfigurationHelper.java:185)
DEBUG 01-22 11:31:13,072 No BootstrapCacheLoaderFactory class specified. Skipping...  (Cache.java:955)
DEBUG 01-22 11:31:13,072 CacheWriter factory not configured. Skipping...  (Cache.java:929)
DEBUG 01-22 11:31:13,072 No CacheExceptionHandlerFactory class specified. Skipping...  (ConfigurationHelper.java:96)
DEBUG 01-22 11:31:13,119 Initialized net.sf.ehcache.store.MemoryStore for com.gong.mybatis.dao.EmployeeMapper  (MemoryStore.java:152)
DEBUG 01-22 11:31:13,181 Using diskstore path D:\44\ehcache  (DiskStorePathManager.java:169)
DEBUG 01-22 11:31:13,181 Holding exclusive lock on D:\44\ehcache\.ehcache-diskstore.lock  (DiskStorePathManager.java:170)
DEBUG 01-22 11:31:13,197 Failed to delete file com%002egong%002emybatis%002edao%002e%0045mployee%004dapper.data  (DiskStorageFactory.java:860)
DEBUG 01-22 11:31:13,197 Failed to delete file com%002egong%002emybatis%002edao%002e%0045mployee%004dapper.index  (DiskStorageFactory.java:860)
DEBUG 01-22 11:31:13,696 Matching data file missing (or empty) for index file. Deleting index file D:\44\ehcache\com%002egong%002emybatis%002edao%002e%0045mployee%004dapper.index  (DiskStorageFactory.java:168)
DEBUG 01-22 11:31:13,712 Failed to delete file com%002egong%002emybatis%002edao%002e%0045mployee%004dapper.index  (DiskStorageFactory.java:860)
DEBUG 01-22 11:31:13,759 Initialised cache: com.gong.mybatis.dao.EmployeeMapper  (Cache.java:1165)
DEBUG 01-22 11:31:13,759 CacheDecoratorFactory not configured for defaultCache. Skipping for ‘com.gong.mybatis.dao.EmployeeMapper‘.  (ConfigurationHelper.java:354)
DEBUG 01-22 11:31:13,907 Cache Hit Ratio [com.gong.mybatis.dao.EmployeeMapper]: 0.0  (LoggingCache.java:62)
DEBUG 01-22 11:31:14,360 ==>  Preparing: select id,last_name lastName,email,gender from tbl_employee where id = ?   (BaseJdbcLogger.java:145)
DEBUG 01-22 11:31:14,391 ==> Parameters: 1(Integer)  (BaseJdbcLogger.java:145)
DEBUG 01-22 11:31:14,453 <==      Total: 1  (BaseJdbcLogger.java:145)
Employee [id=1, lastName=dema, gender=1, email[email protected], dept=null]
DEBUG 01-22 11:31:14,453 put added 0 on heap  (Segment.java:425)
DEBUG 01-22 11:31:14,469 Cache Hit Ratio [com.gong.mybatis.dao.EmployeeMapper]: 0.5  (LoggingCache.java:62)
Employee [id=1, lastName=dema, gender=1, email[email protected], dept=null]
DEBUG 01-22 11:31:14,484 fault removed 0 from heap  (Segment.java:779)
DEBUG 01-22 11:31:14,484 fault added 0 on disk  (Segment.java:796) 

说明配置成功。

原文地址：https://www.cnblogs.com/xiximayou/p/12228262.html