Redis存储对象
在以往面试中,多次被问到Redis怎么存储对象,我支支吾吾半天回答不上来,毕竟我只用过String类型,为了避免以后的尴尬,今天花点时间来整理一下。
本人用的Jedis客户端
首先引入依赖
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>3.2.0</version>
</dependency>
创建一个Jedis实例
package com.xiateng.util;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;
public class JedisUtil {
private static JedisPool jedisPool;
private static final Logger logger = LoggerFactory.getLogger(JedisUtil.class);
static {
// 初始化连接池
JedisPoolConfig jedisPoolConfig = new JedisPoolConfig();
jedisPoolConfig.setMaxTotal(20);
jedisPoolConfig.setMaxIdle(10);
jedisPool = new JedisPool(jedisPoolConfig, "127.0.0.1", 6379);
logger.info("jedisPool连接池初始化====" + jedisPool);
}
public synchronized static Jedis getJedis(){
Jedis jedis = jedisPool.getResource();
// jedis.auth("123456");//密码
return jedis;
}
}
下面我们来实现存储对象
方式一:将对象转化为JSON字符串存入redis
Jedis jedis = JedisUtil.getJedis();
TUser tUser = new TUser();
tUser.setUserName("你好");
tUser.setPassword("2342342");
jedis.set("xiateng", JSON.toJSONString(tUser));
String sss = jedis.get("xiateng");
TUser ssss = JSON.parseObject(sss,TUser.class);
jedis.del("xiateng");
System.out.println("---------------------------: "+ssss.toString());
方式二:将对象序列化后存到redis
封装序列化跟反序列化方法
package com.xiateng.util;
import java.io.*;
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 (IOException e) {
e.printStackTrace();
}
return null;
}
public static Object unSerialize(byte[] bytes){
ByteArrayInputStream bais = null;
try {
bais = new ByteArrayInputStream(bytes);
ObjectInputStream ois = new ObjectInputStream(bais);
return ois.readObject();
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
return null;
}
}
保存对象
Jedis jedis = JedisUtil.getJedis();
jedis.set("code".getBytes(), SerializeUtil.serialize(tUser));
byte[] bytes = jedis.get("code".getBytes());
TUser o = (TUser)SerializeUtil.unSerialize(bytes);
jedis.del("code");
System.out.println(o.toString());
方式三:将对象用Hash数据类型存储
Jedis jedis = JedisUtil.getJedis();
jedis.hset("user", "id", "3");
jedis.hset("user", "name", "xiateng");
jedis.hset("user", "password", "123455");
jedis.hget("user","id");
List<String> user = jedis.hmget("user", new String[]{"id","name","password"});
System.out.println("---------------------------: "+user);
// 输出结果 [3,xiateng,123455]
注意:以序列化的方式存储的对象需要实现 Serializable 接口
Redis可以存储java对象吗
答案:是可以
但是你对象必须要序列化。
redis没有办法把一个没有序列化的对象存储到redis中。
package com.kuangstudy.entiy;
import lombok.Data;
public class User implements java.io.Serializable{
private Integer id;
private String nickname;
private String password;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getNickname() {
return nickname;
}
public void setNickname(String nickname) {
this.nickname = nickname;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
这样太麻烦了,并且存储中文会有乱码,那如何解决呢?只能重新定义一个redisTemplate
package com.kuangstudy.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
@Configuration
public class RedisConfiguration {
@Bean
public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory) {
RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
redisTemplate.setConnectionFactory(redisConnectionFactory);
// 创建一个json的序列化方式
GenericJackson2JsonRedisSerializer jackson2JsonRedisSerializer = new GenericJackson2JsonRedisSerializer();
// 设置value用jackjson进行处理
redisTemplate.setValueSerializer(jackson2JsonRedisSerializer);
// 设置key用string序列化方式
redisTemplate.setKeySerializer(new StringRedisSerializer());
redisTemplate.setHashKeySerializer(new StringRedisSerializer());
redisTemplate.setHashValueSerializer(jackson2JsonRedisSerializer);
redisTemplate.afterPropertiesSet();
return redisTemplate;
}
}
以上为个人经验,希望能给大家一个参考,也希望大家多多支持我们。