深入理解Spring Redis的使用 (七)、Spring Redis 使用 jackson序列化 以及 BaseDao代码

之前在介绍Spring Redis进行存储的时候，都是通过RedisTemplate中的defaultSerializer，即JdkSerializationRedisSerializer。通过Jdk的序列化比较简单，但是有时候线上调试的时候通过控制台查看，完全看不出来存储了什么东西。而且在空间占用和性能上，相比Jackson，完全没有优势。

有过两次线上出问题，定位的时候知道缓存有错，却不知道到底出在那个缓存的字段上，调试非常不方便。于是序列化统统换成了Jackson。

代码如下：

import java.lang.reflect.ParameterizedType;
import java.util.concurrent.TimeUnit;

import javax.annotation.Resource;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.HashOperations;
import org.springframework.data.redis.core.ListOperations;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.SetOperations;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializer;
/**
* key统一为String，省略.HK为hash类型的hashkey类型，HV为value类型或者hashvalue类型（这两个不可能同时存在，所以只取一个）
* @author Han
*/
public class BaseRedisDao<HK, HV> implements InitializingBean{

//实际参数的class start
private Class<HK> hkClass;

private Class<HV> hvClass;

private Class<HK> getHKClass(){
if (hkClass == null) {
hkClass = (Class<HK>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[0];
}
return hkClass;
}

private Class<HV> getHVClass(){
if (hvClass == null) {
hvClass = (Class<HV>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[1];
}
return hvClass;
}
// end
@Autowired
private RedisTemplate<String, HV> redisTemplate;

protected ValueOperations<String, HV> valueOperations;
//
protected HashOperations<String, HK, HV> hashOperations;
//
protected ListOperations<String, HV> listOperations;

protected SetOperations<String, HV> setOperations;
/**
*
* @param key
* @param value
* @param expire
* @return
*/
protected void set(String key, HV value, long expire) {
valueOperations.set(key, value, expire, TimeUnit.SECONDS);
}

/**
* get value
*
* @param key
* @return
*/
protected HV get(String key) {
return valueOperations.get(key);
}

/**
* key delete
* @param key
*/
protected void delete(String key){
getRedisTemplate().delete(key);
}

/**
* key exist
* @param key
* @return
*/
protected boolean hasKey(String key){
return  getRedisTemplate().hasKey(key);
}
/**
*key expire
* @param key
* @param timeout
* @param unit
* @return
*/
protected Boolean expire(String key,long timeout,TimeUnit unit){
return getRedisTemplate().expire(key, timeout, unit);
}
/**
* redistemplate是全局唯一的，子类不要出现对redistemplate的成员变量的设置(比如keyserializer,)
* @return
*/
RedisTemplate<String, HV> getRedisTemplate() {
return redisTemplate;
}
/**
* 当需要更改serializer,可以直接通过connection.set等方法实现
* @param callback
* @return
*/
protected <T> T execute(RedisCallback<T> callback){
return redisTemplate.execute(callback);
}
/**
* 获取stringserializer
*/
protected RedisSerializer<String> getStringSerializer(){
return redisTemplate.getStringSerializer();
}
/**
* 获取JdkSerializationRedisSerializer
*/
@SuppressWarnings("unchecked")
protected <T> RedisSerializer<T> getDefaultSerializer(){
return (RedisSerializer<T>) redisTemplate.getDefaultSerializer();
}
/**
* 获取stringserializer
* @return
*/
@SuppressWarnings("unchecked")
protected  RedisSerializer<String> getKeySerializer(){
return (RedisSerializer<String>) redisTemplate.getKeySerializer();
}
/**
* 获取jackson2jsonredisserializer
* @return
*/
protected RedisSerializer<HV> getValueSerializer(){
return (RedisSerializer<HV>) redisTemplate.getValueSerializer();
}
/**
* 获取jackson2jsonredisserializer
* @return
*/
@SuppressWarnings("unchecked")
protected RedisSerializer<HK> getHashKeySerializer() {
return (RedisSerializer<HK>) redisTemplate.getHashKeySerializer();
}

/**
* 获取jackson2jsonredisserializer
* @return
*/
@SuppressWarnings("unchecked")
protected RedisSerializer<HV> getHashValueSerializer() {
return (RedisSerializer<HV>) redisTemplate.getHashValueSerializer();
}

@Override
public void afterPropertiesSet() throws Exception {
if(getHKClass() == null || getHVClass() == null){
throw new IllegalArgumentException("获取泛型class失败");
}
//
valueOperations = redisTemplate.opsForValue();
hashOperations = redisTemplate.opsForHash();
listOperations = redisTemplate.opsForList();
setOperations = redisTemplate.opsForSet();
//
redisTemplate.setValueSerializer(new Jackson2JsonRedisSerializer<HV>(getHVClass()));
redisTemplate.setHashKeySerializer(new Jackson2JsonRedisSerializer<HK>(getHKClass()));
redisTemplate.setHashValueSerializer(new Jackson2JsonRedisSerializer<HV>(getHVClass()));
}
}

对于key的序列化，直接在配置文件定义

<bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate" scope="prototype">
<property name="connectionFactory" ref="jedisConnectionFactory" />
<property name="keySerializer" ref="stringKeySerializer"/>
<property name="enableTransactionSupport" value="true"/><!-- 配置true可以使用transactional控制事务，spring已经提供支持 -->
</bean>