010_ StringRedisTemplate

010_StringRedisTemplate

The above disadvantage is that it will use memory space to occupy bytecode

1、 To save memory space , We don't use it JSON Serialization to handle value, Instead, use a unified String Serializer , It is required that only String Type of key and value.

2、 When you want to store Java When the object , Manually complete the serialization and deserialization of objects

3、Spring One is provided in StringRedisTemplate class , its key as well as value All default to String The way . It eliminates our custom RedisTemplate The process of .

The code tests are as follows .

package com.ym.redisdemo;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.ym.redisdemo.pojo.User;
import lombok.val;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;

@SpringBootTest
class RedisStringTests {
    

    // Inject Redis
    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    /** *  Store string test  */
    @Test
    void contextLoads() {
    
        // Write a piece of String data 
        stringRedisTemplate.opsForValue().set("lover"," Li Yifeng ");
        // obtain String data 
        Object name = stringRedisTemplate.opsForValue().get("lover");
        System.out.println("lover="+name);
    }

    private static final ObjectMapper mapper=new ObjectMapper();
    /** *  Storage object test  */
    @Test
    void testSaveUser() throws JsonProcessingException {
    
        // Create the object first 
        User user=new User(" Li Yifeng ",21);
        // Manual serialization 
        String json = mapper.writeValueAsString(user);
        // Write data 
        stringRedisTemplate.opsForValue().set("user:101",json);
        // get data 
        String  o = stringRedisTemplate.opsForValue().get("user:101");
        // Manual deserialization 
        User  user1 = mapper.readValue(o, User.class);
        System.out.println(user1);
    }

}

summary ：

About RedisTemplate Two serialization practices

• programme 1：
  （1） Customize RedisTemplate
  （2） modify RedisTemplate serializers GenericJackson2JsonRedisSerializer
• programme 2：
  （1） Use StringRedisTemplate
  （2） write in Redis when , You need to manually serialize the object to Json
  （3） Read Redis when , Read manually Json Deserialize to object