Shulou(Shulou.com)06/01 Report--

This article will explain in detail how mybatis combines redis to achieve secondary caching. The editor thinks it is very practical, so I share it for you as a reference. I hope you can get something after reading this article.

One: custom mybatis cache

We know that any mybatis secondary cache needs to implement an interface, which is called org.apache.ibatis.cache.Cache. The code is as follows:

Package com.demo.spring.mybatis.cache

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 com.demo.spring.mybatis.util.SerializeUtil

Import redis.clients.jedis.Jedis

Import redis.clients.jedis.JedisPool

Public class MybatisRedisCache implements Cache {

Private static Logger logger = LoggerFactory.getLogger (MybatisRedisCache.class)

Private Jedis redisClient = createReids ()

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 ("127.0.0.1", 6379)

Return pool.getResource ()

}

}

The above code is simply a basic Cache implementation, defining a serialized utility class

Package com.demo.spring.mybatis.util

Import java.io.ByteArrayInputStream

Import java.io.ByteArrayOutputStream

Import java.io.ObjectInputStream

Import java.io.ObjectOutputStream

Public class SerializeUtil {

Public static byte [] serialize (Object object) {

ObjectOutputStream oos = null

ByteArrayOutputStream baos = null

Try {

/ / Serialization

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 {

/ / deserialization

Bais = new ByteArrayInputStream (bytes)

ObjectInputStream ois = new ObjectInputStream (bais)

Return ois.readObject ()

} catch (Exception e) {

}

Return null

}

}

Then configure it in mapper.xml

Of course, the following code needs to be configured in the main configuration file, which means to enable secondary cache. It is disabled by default.

So the configuration and code have been completed and the results are as follows:

Why does the second time go to the first-level cache?

This is analyzed when talking about the second-level cache source code, and the results of the previous query are cached only when commit is executed.

Open it? redis check it below, because the result of serialization is stored, but we can still vaguely see some information to the following figure.

This is the end of this article on "how mybatis combines redis to achieve secondary cache". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, please share it out for more people to see.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.