mybatis默认
缓存是PerpetualCache，可以查看一下它的源码，发现其是
Cache接口的实现；那么我们的缓存只要实现该接口即可。
该接口有以下方法需要实现：
String getId();
int getSize();
void putObject(Object key, Object value);
Object getObject(Object key);
Object removeObject(Object key);
void clear();
ReadWriteLock getReadWriteLock();
下面是 mybatis整合redis，做 数据查询的语句结果缓存，我们通过 mybatis redis整合实现代码和配置了解它们的技术实现：
1 实现类：
MybatisRedisCache.java
SerializeUtil.java
2 spring中的mybatis配置
<!-- mybatis配置 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="mapperLocations" value=" classpath*:app/mapper/**/*. xml"/>
<property name="configLocation" value="classpath:/mybatis/mybatis-config.xml" />
</bean>
3 mybatis-config.xml 中的settings配制
<settings>
<!-- 开启缓存支持 -->
<setting name="cacheEnabled" value="true" />
.......
</settings>
4 在需要加缓存的sqlMap中加入<cache eviction=" LRU" type="app.platform.mybatis.MybatisRedisCache" />
例：
<mapper namespace="SYS_ROLE">
<!-- 缓存 -->
<cache eviction=" LRU" type="app.platform.mybatis.MybatisRedisCache" />
<!-- 查询所有 -->
<select id="findAll" parameterType=" HashMap" resultType="HashMap">
select
<include refid="base_column" />
from SYS_ROLE
where 1=1
<if test="BUS_TYPE!=null and BUS_TYPE!=''">
and BUS_TYPE =#{BUS_TYPE}
</if>
<if test=" ENABLE!=null and ENABLE!=''">
and ENABLE =#{ENABLE}
</if>
<if test="ROLE_NAME!=null and ROLE_NAME!=''">
and ROLE_NAME like '%'||#{ROLE_NAME}||'%'
</if>
<if test="ROLE_OTHER_NAME!=null and ROLE_OTHER_NAME!=''">
and ROLE_OTHER_NAME like '%'||#{ROLE_OTHER_NAME}||'%'
</if>
</select>
</mapper>
在项目中，我们可以检测到，首次查询是有语句打印，第二次则直接从redis缓存中获取。
该接口有以下方法需要实现：
String getId();
int getSize();
void putObject(Object key, Object value);
Object getObject(Object key);
Object removeObject(Object key);
void clear();
ReadWriteLock getReadWriteLock();
下面是 mybatis整合redis，做 数据查询的语句结果缓存，我们通过 mybatis redis整合实现代码和配置了解它们的技术实现：
1 实现类：
MybatisRedisCache.java
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package
app.platform.mybatis
import
java.util.concurrent.locks.ReadWriteLock;
import
java.util.concurrent.locks.ReentrantReadWriteLock;
import
org.apache.ibatis.cache.Cache;
import
org.slf4j.Logger;
import
org.slf4j.LoggerFactory;
import
redis.clients.jedis.Jedis;
import
redis.clients.jedis.JedisPool;
import
redis.clients.jedis.JedisPoolConfig;
/**
* redis 整合mybatis Cache实现类
*
* <a href="http://www.zyiqibook.com">在一起 学习交流分享网 IT技术分享</a>
*/
public
class
MybatisRedisCache
implements
Cache {
private
static
Logger logger = LoggerFactory.getLogger(MybatisRedisCache.
class
);
private
Jedis redisClient=createReids();
/** The ReadWriteLock. */
private
final
ReadWriteLock readWriteLock =
new
ReentrantReadWriteLock();
private
String id;
public
MybatisRedisCache(
final
String id) {
if
(id ==
null
) {
throw
new
IllegalArgumentException(
"Cache instances require an ID"
);
}
logger.debug(
">>>>>>>>>>>>>>>>>>>>>>>>MybatisRedisCache:id="
+id);
this
.id = id;
}
@Override
public
String getId() {
return
this
.id;
}
@Override
public
int
getSize() {
return
Integer.valueOf(redisClient.dbSize().toString());
}
@Override
public
void
putObject(Object key, Object value) {
logger.debug(
">>>>>>>>>>>>>>>>>>>>>>>>putObject:"
+key+
"="
+value);
redisClient.set(SerializeUtil.serialize(key.toString()), SerializeUtil.serialize(value));
}
@Override
public
Object getObject(Object key) {
Object value = SerializeUtil.unserialize(redisClient.get(SerializeUtil.serialize(key.toString())));
logger.debug(
">>>>>>>>>>>>>>>>>>>>>>>>getObject:"
+key+
"="
+value);
return
value;
}
@Override
public
Object removeObject(Object key) {
return
redisClient.expire(SerializeUtil.serialize(key.toString()),
0
);
}
@Override
public
void
clear() {
redisClient.flushDB();
}
@Override
public
ReadWriteLock getReadWriteLock() {
return
readWriteLock;
}
protected
static
Jedis createReids(){
JedisPool pool =
new
JedisPool(
new
JedisPoolConfig(),
"10.12.162.85"
);
return
pool.getResource();
}
}
|
SerializeUtil.java
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/**
* redis 整合mybatis 序列化工具类
*
* <a href="http://www.zyiqibook.com">在一起 学习交流分享网 IT技术分享</a>
*/
public
class
SerializeUtil {
public
static
byte
[] serialize(Object object) {
ObjectOutputStream oos =
null
;
ByteArrayOutputStream baos =
null
;
try
{
//序列化
baos =
new
ByteArrayOutputStream();
oos =
new
ObjectOutputStream(baos);
oos.writeObject(object);
byte
[] bytes = baos.toByteArray();
return
bytes;
}
catch
(Exception e) {
e.printStackTrace();
}
return
null
;
}
public
static
Object unserialize(
byte
[] bytes) {
ByteArrayInputStream bais =
null
;
try
{
//反序列化
bais =
new
ByteArrayInputStream(bytes);
ObjectInputStream ois =
new
ObjectInputStream(bais);
return
ois.readObject();
}
catch
(Exception e) {
}
return
null
;
}
}
|
2 spring中的mybatis配置
<!-- mybatis配置 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="mapperLocations" value=" classpath*:app/mapper/**/*. xml"/>
<property name="configLocation" value="classpath:/mybatis/mybatis-config.xml" />
</bean>
3 mybatis-config.xml 中的settings配制
<settings>
<!-- 开启缓存支持 -->
<setting name="cacheEnabled" value="true" />
.......
</settings>
4 在需要加缓存的sqlMap中加入<cache eviction=" LRU" type="app.platform.mybatis.MybatisRedisCache" />
例：
<mapper namespace="SYS_ROLE">
<!-- 缓存 -->
<cache eviction=" LRU" type="app.platform.mybatis.MybatisRedisCache" />
<!-- 查询所有 -->
<select id="findAll" parameterType=" HashMap" resultType="HashMap">
select
<include refid="base_column" />
from SYS_ROLE
where 1=1
<if test="BUS_TYPE!=null and BUS_TYPE!=''">
and BUS_TYPE =#{BUS_TYPE}
</if>
<if test=" ENABLE!=null and ENABLE!=''">
and ENABLE =#{ENABLE}
</if>
<if test="ROLE_NAME!=null and ROLE_NAME!=''">
and ROLE_NAME like '%'||#{ROLE_NAME}||'%'
</if>
<if test="ROLE_OTHER_NAME!=null and ROLE_OTHER_NAME!=''">
and ROLE_OTHER_NAME like '%'||#{ROLE_OTHER_NAME}||'%'
</if>
</select>
</mapper>
在项目中，我们可以检测到，首次查询是有语句打印，第二次则直接从redis缓存中获取。
