SpringBoot Data Redis to operate Redis

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1. Redis startup

The main role of Redis

Cooperate with relational database for cache

Various data structures store persistent data

installation location

CentOS 7

start up

start redis

cd /usr/local/bin
redis-server /etc/redis.conf
ps -ef | grep redis

close redis

redis-cli shutdown

Enter the client

redis-cli

Test connection
After entering the client, enter:

ping

2. Operate Redis in Java

<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>

@Test
public void testRedis(){
    
    
    // 1、获取连接
    Jedis jedis = new Jedis("192.168.10.129", 6379);

    // 2、执行具体操作
    //添加一个[key, value]
    jedis.set("username", "张三");

    // 获取value
    String username = jedis.get("username");
    System.out.println("username = " + username);

    //删除
    jedis.del("username");
    System.out.println("username = " + username);

    // 存hashset
    jedis.hset("myhashset", "addr","beijing");
    String hget = jedis.hget("myhashset", "addr");
    System.out.println("hget = " + hget);

    // 3、关闭连接
    jedis.close();
}

3. Spring Data Redis (emphasis)

pom

<!--开启redis缓存-->
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

application.yaml

spring:
  redis:
    host: 192.168.10.129
#    port: 6379 #不写就是默认端口号6379
#    database: 0 #操作的是0号数据库，不写就是默认的

RedisTemplate

test connection

package com.jerry.springdataredis;

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.ValueOperations;

@SpringBootTest
class SpringdataredisApplicationTests {
    
    

    @Autowired
    RedisTemplate redisTemplate;

    @Test
    void testString() {
    
    
        redisTemplate.opsForValue().set("city","beijing");

    }

}

Looking at the redis database, you will find that there are a bunch of escape characters in front of [key, values], because the default RedisTemplate has been serialized

Configure the Redis serializer

To solve this problem, we need to manually add configuration classes and set our own serializers

package com.jerry.springdataredis.config;

import org.springframework.cache.annotation.CachingConfigurerSupport;
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.StringRedisSerializer;

@Configuration
public class RedisConfig extends CachingConfigurerSupport {
    
    

    @Bean
    public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory connectionFactory) {
    
    
        RedisTemplate<Object, Object> redisTemplate = new RedisTemplate<>();

        //默认的Key序列化器为：JdkSerializationRedisSerializer
        redisTemplate.setKeySerializer(new StringRedisSerializer()); // key序列化
        //redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer()); // value序列化
        redisTemplate.setHashKeySerializer(new StringRedisSerializer()); // hash序列化

        redisTemplate.setConnectionFactory(connectionFactory);
        return redisTemplate;
    }
}

redisTemplate operates common data types

package com.jerry.springdataredis;

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.ValueOperations;

import java.util.List;
import java.util.Set;
import java.util.concurrent.TimeUnit;

@SpringBootTest
class SpringdataredisApplicationTests {
    
    

    @Autowired
    RedisTemplate redisTemplate;

    /**
     * 操作 String 类型的数据
     */
    @Test
    void testString() {
    
    
        redisTemplate.opsForValue().set("city123","beijing123");

        Object o = redisTemplate.opsForValue().get("city123");
        System.out.println("o = " + o);

        redisTemplate.opsForValue().set("k1", "v1", 10L, TimeUnit.SECONDS);

        Boolean aBoolean = redisTemplate.opsForValue().setIfAbsent("k1", "v1");
        System.out.println("aBoolean = " + aBoolean);

    }

    /**
     * 操作 Hash 类型的数据
     */
    @Test
    void testHash(){
    
    
        // 存值
        redisTemplate.opsForHash().put("001", "name", "xiaoming");
        redisTemplate.opsForHash().put("001", "age", "20");
        redisTemplate.opsForHash().put("001", "city", "Shanghai");

        // 取值
        String name = (String) redisTemplate.opsForHash().get("001", "name");
        System.out.println("name = " + name);

        // 获取hash结构中的所有字段
        Set keys = redisTemplate.opsForHash().keys("001");
        for (Object key : keys) {
    
    
            System.out.println(key);
        }

        // 获取hash结构中的所有值
        List values = redisTemplate.opsForHash().values("001");
        for (Object value : values) {
    
    
            System.out.println(value);
        }
    }

    /**
     * 操作 List 类型的数据(有序集合)
     */
    @Test
    void testList(){
    
    
        // 存值
        redisTemplate.opsForList().leftPush("myList", "a");
        redisTemplate.opsForList().leftPushAll("myList", "b","c","d");

        // 取值
        List<String> myList = redisTemplate.opsForList().range("myList", 0, -1);
        for (String value : myList) {
    
    
            System.out.println(value); // d c b a
        }

        // 获取列表长度
        Long size = redisTemplate.opsForList().size("myList");
        int isize = size.intValue();

        for (int i = 0; i < isize; i++) {
    
    
            // 出队列
            String element = (String) redisTemplate.opsForList().rightPop("myList");
            System.out.println(element); // a b c d
        }

    }

    /**
     * 操作set类型数据(无序集合，可以重复)
     */
    @Test
    void testSet(){
    
    
        // 存值， 可以有重复的元素
        redisTemplate.opsForSet().add("mySet","a","b","c","a","b");

        // 取值
        Set<String> mySet = redisTemplate.opsForSet().members("mySet");
        for (String s : mySet) {
    
    
            System.out.println(s); // c b a
        }
        // 删除元素
        redisTemplate.opsForSet().remove("mySet", "a","b");
    }


    /**
     * 操作 ZSet 类型数据(有序集合，按分数大小排序)
     */
    @Test
    void testZSet(){
    
    
        // 存值， 不能有重复的元素
        redisTemplate.opsForZSet().add("myZSet", "a", 10.0);
        redisTemplate.opsForZSet().add("myZSet", "b", 11.0);
        redisTemplate.opsForZSet().add("myZSet", "c", 12.0);
        redisTemplate.opsForZSet().add("myZSet", "a", 13.0);

        // 取值
        Set<String> myZSet = redisTemplate.opsForZSet().range("myZSet", 0, -1);
        for (String s : myZSet) {
    
    
            System.out.println(s); // b c a
        }
        System.out.println();

        // 修改分数
        redisTemplate.opsForZSet().incrementScore("myZSet", "b", 20.0);

        myZSet = redisTemplate.opsForZSet().range("myZSet", 0, -1);
        for (String s : myZSet) {
    
    
            System.out.println(s); // c a b
        }
        System.out.println();

        // 删除元素
        redisTemplate.opsForZSet().remove("myZSet", "a","b");

        myZSet = redisTemplate.opsForZSet().range("myZSet", 0, -1);
        for (String s : myZSet) {
    
    
            System.out.println(s); // c
        }
    }
}

Universal operations, which can be operated on different data types

/**
 * 通用操作，针对不同的数据类型都可以操作
 */
@Test
void testCommon(){
    
    
    // 获取redis中所有的key
    Set<String> keys = redisTemplate.keys("*");
    for (String key : keys) {
    
    
        System.out.println(key);
    }

    // 判断指定key 是否存在
    Boolean hasKey = redisTemplate.hasKey("jerry");
    System.out.println("hasKey = " + hasKey);

    // 删除指定 key
    redisTemplate.delete("myZSet");

    // 获取指定key 对应的value的数据类型
    DataType dataType = redisTemplate.type("mySet");
    System.out.println(dataType.name());
}

–end–