Redis学习-- Java操作Redis的几种方式

Posted 2021-07-07 三笠·阿卡曼

Jedis操作Redis

创建idea工程

建立一个Maven项目，导入Jedis依赖即可：

<!-- 导入Jedis依赖 -->
        <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
            <version>3.2.0</version>
        </dependency>

导入依赖之后创建JedisDemo测试类

package com.vleus.jedis;

import redis.clients.jedis.Jedis;

/**
 * @author vleus
 * @date 2021年07月03日 23:52
 */
public class JedisDemo1 {

    public static void main(String[] args) {

        //创建Jedis对象
        Jedis jedis = new Jedis("192.168.37.139",6379);
		//测试Jedis客户端是否能够连接上Redis
        System.out.println(jedis.ping());
    }
}

输出PONG表示连接成功~

注意：

第一次测试时如果连接不上虚拟机的Redis，报连接不上的异常有两个问题需要解决：

• 首先，kill掉Redis的进程，然后修改Reids的启动使用的配置文件
  • 注释掉bind的配置；
  • 同时将protected-mode的值改为no
    
• 第二步，关掉Linux的防火墙（这里仅是在做学习时使用，生产环境别这么干）

systemctl stop firewalld
systemctl disable firewalld

反正我是这么解决的。

Jedis操作Redis

1、创建idea springboot项目，引入依赖

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

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

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

        <!-- spring2.x继承redis需要commons-pool -->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-pool2</artifactId>
            <version>2.6.2</version>
        </dependency>
		<dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.8.3</version>
        </dependency>

    </dependencies>

2、创建RedisConfig配置类

@EnableCaching
@Configuration
public class RedisConfig {

    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        RedisSerializer<String> redisSerializer = new StringRedisSerializer();
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);
        template.setConnectionFactory(factory);
        //key序列化方式
        template.setKeySerializer(redisSerializer);
        //value序列化
        template.setValueSerializer(jackson2JsonRedisSerializer);
        //value hashmap序列化
        template.setHashValueSerializer(jackson2JsonRedisSerializer);
        return template;
    }

    @Bean
    public CacheManager cacheManager(RedisConnectionFactory factory) {
        RedisSerializer<String> redisSerializer = new StringRedisSerializer();
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        //解决查询缓存转换异常的问题
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);
        // 配置序列化（解决乱码的问题）,过期时间600秒
        RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig()
                .entryTtl(Duration.ofSeconds(600))
                .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(redisSerializer))
                .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jackson2JsonRedisSerializer))
                .disableCachingNullValues();
        RedisCacheManager cacheManager = RedisCacheManager.builder(factory)
                .cacheDefaults(config)
                .build();
        return cacheManager;
    }

}

简单的Controller测试

/**
 * @author vleus
 * @date 2021年07月04日 13:06
 */
@RestController
@RequestMapping(value = "/redisTest")
public class RedisTestController {

    @Resource
    private RedisTemplate redisTemplate;

    @GetMapping
    public String testRedis() {
        //设置值到redis
        redisTemplate.opsForValue().set("name","jack");
        //从redis中获取值
        String name = (String) redisTemplate.opsForValue().get("name");
        return name;
    }
}