Redis看这一篇就够了

@SpringBootTest
public class StringRedisTemplateTest {
    @Autowired
    private StringRedisTemplate stringRedisTemplate;
    @Test
    void get(){
        ValueOperations<String, String> ops = stringRedisTemplate.opsForValue();
        String name = ops.get("name");
        System.out.println(name);
    }
}

5.3.2 使用方式

5.3.2.1 环境搭建

第一步：创建maven项目springdataredis_demo，配置pom.xml文件

<?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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.5</version>
        <relativePath/>
    </parent>
    <groupId>com.itheima</groupId>
    <artifactId>springdataredis_demo</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.4.5</version>
            </plugin>
        </plugins>
    </build>
</project>

第二步：编写启动类

package com.itheima;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class App {

    public static void main(String[] args) {
        SpringApplication.run(App.class,args);
    }

}

第三步：配置application.yml

spring:
  application:
    name: springdataredis_demo
  #Redis相关配置
  redis:
    host: localhost
    port: 6379
    #password: 123456
    database: 0 #操作的是0号数据库
    jedis:
      #Redis连接池配置
      pool:
        max-active: 8 #最大连接数
        max-wait: 1ms #连接池最大阻塞等待时间
        max-idle: 4 #连接池中的最大空闲连接
        min-idle: 0 #连接池中的最小空闲连接

解释说明：

spring.redis.database：指定使用Redis的哪个数据库，Redis服务启动后默认有16个数据库，编号分别是从0到15。

可以通过修改Redis配置文件来指定数据库的数量。

第四步：提供配置类

package com.itheima.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;

/**
 * Redis配置类
 */
@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());
        redisTemplate.setHashKeySerializer(new StringRedisSerializer());

        redisTemplate.setConnectionFactory(connectionFactory);

        return redisTemplate;
    }

}

解释说明：

当前配置类不是必须的，因为 Spring Boot 框架会自动装配 RedisTemplate 对象，但是默认的key序列化器为JdkSerializationRedisSerializer，导致我们存到Redis中后的数据和原始数据有差别

第五步：提供测试类

package com.itheima.test;

import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@SpringBootTest
@RunWith(SpringRunner.class)
public class SpringDataRedisTest {

    @Autowired
    private RedisTemplate redisTemplate;
    
}

5.3.2.2 操作字符串类型数据

/**
 * 操作String类型数据
*/
@Test
public void testString(){
    //存值
    redisTemplate.opsForValue().set("city123","beijing");

    //取值
    String value = (String) redisTemplate.opsForValue().get("city123");
    System.out.println(value);

    //存值，同时设置过期时间
    redisTemplate.opsForValue().set("key1","value1",10l, TimeUnit.SECONDS);

    //存值，如果存在则不执行任何操作
    Boolean aBoolean = redisTemplate.opsForValue().setIfAbsent("city1234", "nanjing");
    System.out.println(aBoolean);
}

5.3.2.3 操作哈希类型数据

/**
 * 操作Hash类型数据
*/
@Test
public void testHash(){
    HashOperations hashOperations = redisTemplate.opsForHash();

    //存值
    hashOperations.put("002","name","xiaoming");
    hashOperations.put("002","age","20");
    hashOperations.put("002","address","bj");

    //取值
    String age = (String) hashOperations.get("002", "age");
    System.out.println(age);

    //获得hash结构中的所有字段
    Set keys = hashOperations.keys("002");
    for (Object key : keys) {
        System.out.println(key);
    }

    //获得hash结构中的所有值
    List values = hashOperations.values("002");
    for (Object value : values) {
        System.out.println(value);
    }
}

5.3.2.4 操作列表类型数据

/**
 * 操作List类型的数据
*/
@Test
public void testList(){
    ListOperations listOperations = redisTemplate.opsForList();

    //存值
    listOperations.leftPush("mylist","a");
    listOperations.leftPushAll("mylist","b","c","d");

    //取值
    List<String> mylist = listOperations.range("mylist", 0, -1);
    for (String value : mylist) {
        System.out.println(value);
    }

    //获得列表长度 llen
    Long size = listOperations.size("mylist");
    int lSize = size.intValue();
    for (int i = 0; i < lSize; i++) {
        //出队列
        String element = (String) listOperations.rightPop("mylist");
        System.out.println(element);
    }
}

5.3.2.5 操作集合类型数据

/**
 * 操作Set类型的数据
*/
@Test
public void testSet(){
    SetOperations setOperations = redisTemplate.opsForSet();

    //存值
    setOperations.add("myset","a","b","c","a");

    //取值
    Set<String> myset = setOperations.members("myset");
    for (String o : myset) {
        System.out.println(o);
    }

    //删除成员
    setOperations.remove("myset","a","b");

    //取值
    myset = setOperations.members("myset");
    for (String o : myset) {
        System.out.println(o);
    }

}

5.3.2.6 操作有序集合类型数据

/**
 * 操作ZSet类型的数据
*/
@Test
public void testZset(){
    ZSetOperations zSetOperations = redisTemplate.opsForZSet();

    //存值
    zSetOperations.add("myZset","a",10.0);
    zSetOperations.add("myZset","b",11.0);
    zSetOperations.add("myZset","c",12.0);
    zSetOperations.add("myZset","a",13.0);

    //取值
    Set<String> myZset = zSetOperations.range("myZset", 0, -1);
    for (String s : myZset) {
        System.out.println(s);
    }

    //修改分数
    zSetOperations.incrementScore("myZset","b",20.0);

    //取值
    myZset = zSetOperations.range("myZset", 0, -1);
    for (String s : myZset) {
        System.out.println(s);
    }

    //删除成员
    zSetOperations.remove("myZset","a","b");

    //取值
    myZset = zSetOperations.range("myZset", 0, -1);
    for (String s : myZset) {
        System.out.println(s);
    }
}

5.3.2.7 通用操作

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

    //判断某个key是否存在
    Boolean itcast = redisTemplate.hasKey("itcast");
    System.out.println(itcast);

    //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());

}

总结：Redis用于热点数据十分高效，希望对您有帮助，感谢阅读

结束语：裸体一旦成为艺术，便是最圣洁的。道德一旦沦为虚伪，便是最下流的。
勇敢去做你认为正确的事，不要被世俗的流言蜚语所困扰。