Recently, redis cache has been used in our work, so we share something we have summarized. This article uses StringRedisTemplate for learning. The value here is: (1) StringRedisTemplate needs to be serialized when performing batch deletion operation, (2) the update operation is the same as the add operation, and the next code is as follows:
1. Create a Spring boot project and introduce Redis dependency (pom.xml is as follows):

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.test</groupId>
    <artifactId>redis</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>redis</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.0.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

2. Write the spring boot configuration file. The content of my configuration here is simple. If you need other configurations, you can check them on the official website

#Redis 
spring.redis.host=192.168.100.86
spring.redis.password=admin
spring.redis.port=6379

server.port=8081

3. Next, we start to write tests
(1) establish entity class:
User:

package com.test.redis.entity;

public class User {
    private Integer id;
    private String name;
    private String password;

    public User() {
        super();
    }

    public User(Integer id, String name, String password) {
        super();
        this.id = id;
        this.name = name;
        this.password = password;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "User [id=" + id + ", name=" + name + ", password=" + password + "]";
    }

}

(2) service layer, which mainly defines various operation methods of redis
RedisService:

package com.test.redis.service;

import java.util.List;
import java.util.Map;

import javax.annotation.Resource;

import org.springframework.data.redis.core.HashOperations;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.serializer.JdkSerializationRedisSerializer;
import org.springframework.stereotype.Service;

@Service
public class RedisService {
    @Resource
    private StringRedisTemplate template;

    /**
     * Store or modify data
     * 
     * @param modelMap
     * @param mapName
     */
    public void setKey(String mapName, Map<String, Object> modelMap) {
        HashOperations<String, Object, Object> hps = template.opsForHash();
        hps.putAll(mapName, modelMap);
    }

    /**
     * Get data Map
     * 
     * @param mapName
     * @return
     */
    public Map<Object, Object> getMapValue(String mapName) {
        HashOperations<String, Object, Object> hps = this.template.opsForHash();
        return hps.entries(mapName);

    }

    /**
     * Get data value
     * 
     * @param mapName
     * @param hashKey
     * @return
     */
    public Object getValue(String mapName, String hashKey) {
        HashOperations<String, Object, Object> hps = this.template.opsForHash();
        return hps.get(mapName, hashKey);

    }

    /**
     * Bulk delete cached data
     * 
     * @param keys
     */
    public void deleteData(List<String> keys) {
        // Serialize template before bulk delete
        template.setKeySerializer(new JdkSerializationRedisSerializer());
        template.delete(keys);
    }
}

(3) controller layer code, demonstrating the operation (adding and obtaining values):

package com.test.redis.web;

import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import com.test.redis.entity.User;
import com.test.redis.service.RedisService;

@Controller
public class UserController {

    private static final String mapName="mapName";
    @Autowired
    private RedisService redisService;

    @GetMapping( "/add.do")
    @ResponseBody
    public Map<Object, Object> addUser(HttpServletRequest request){
        Map<String, Object> modelMap=new HashMap<String,Object>();
        User user=new User();
        user.setName("hehename");
        user.setPassword("hehePassword");
        //Store hash value
        modelMap.put("name", user.getName());
        modelMap.put("password", user.getPassword());
        redisService.setKey(mapName, modelMap);
        //Get map collection
        Map<Object, Object> modelMap1= redisService.getMapValue(mapName);
        Object value= redisService.getValue(mapName, "name");
        System.out.println(" value : "+value);
        modelMap1.put("From cache by key Obtained value", value);
        return modelMap1;
    }

}

Presentation results at the front desk:

(4) delete and get value operation:

@GetMapping( "/delete.do")
    @ResponseBody
    public Map<Object, Object> deleteUser(HttpServletRequest request){
        //Get the key value to be deleted. Here we do the bulk deletion
        List<String> keys=new ArrayList<>();
        keys.add("heheanme");
        //Start delete operation
        redisService.deleteData(keys);
        //Get map collection
        Map<Object, Object> modelMap1= redisService.getMapValue(mapName);
        Object value= redisService.getValue(mapName, "name");
        System.out.println(" value : "+value);
        modelMap1.put("From cache by key Obtained value", value);
        return modelMap1;
    }

Results displayed in the foreground:

This shows that the operation is successful