Redis 使用

Jedis

引入pom

Jedis官网:  GitHub - redis/jedis: Redis Java client designed for performance and ease of use.

        <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
            <version>4.2.0</version>
        </dependency>

增加Junit依赖用于测试

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

测试代码

public class jedisTest {
    private Jedis jedis;

    @Before
    public void setUp(){
        //建立连接
        jedis = new Jedis("192.168.99.100", 56379);
        //设置密码
        jedis.auth("123321");
        //选择库
        jedis.select(0);
    }

    @Test
    public void testString() {
        String result = jedis.set("name", "lisi");
        System.out.println(result);
        String name = jedis.get("name");
        System.out.println(name);
    }

    @Test
    public void testHash() {
        jedis.hset("lb:user:2", "name","wangwau");
        jedis.hset("lb:user:2", "age","32");
        Map<String, String> map = jedis.hgetAll("lb:user:2");
        System.out.println(map);
    }

    @After
    public void down() {
        if (jedis != null){
            jedis.close();
        }
    }
}

Jedis连接池

Jedis本身是线程不安全的，并且频繁的创建和销毁连接会有性能损耗，推荐使用Jedis连接池代替Jedis的直连方式。

public class JedisPoolFactory {

    private static final JedisPool jedisPool;

    static {
//        配置连接池
        JedisPoolConfig config = new JedisPoolConfig();
        config.setMaxTotal(8);
        config.setMaxIdle(8);
        config.setMinIdle(0);
        config.setMaxWait(Duration.ofMillis(1000));
        jedisPool = new JedisPool(config, "192.168.99.100", 56379);
    }

    public static Jedis getJedisResource() {
        return jedisPool.getResource();
    }
}

Lettuce

 

 引入pom依赖

        <!-- springboot redis配置 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
        <!-- redis需要设置连接池依赖 -->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-pool2</artifactId>
        </dependency>

设置springboot配置

spring:
  redis:
    host: 192.168.99.100
    port: 56379
    password: 123321
    lettuce:
      pool:
        max-active: 8
        max-idle: 8
        min-idle: 0
        max-wait: 100ms

测试代码

@SpringBootTest
class RedisSpringbootApplicationTests {

    @Autowired
    private RedisTemplate redisTemplate;

    @Test
    void testString() {
        redisTemplate.opsForValue().set("name", "李四");
        Object value = redisTemplate.opsForValue().get("name");
        System.out.println(value);
    }
}

结果为:

 

可以发现存入的key已经不是name了，原因是RedisTemplate的设置的key和value类型都是Object类型，所以做了序列化处理。则需要自定义序列化器来替代默认的序列化。

Note: json的序列化器依赖 jackson，所以需要导入依赖，但是在平常开发过程中，springmvc的依赖中带有jackson的依赖则不需要单独导入。

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
        </dependency>

@Configuration
public class RedisConfig {

    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory connectionFactory) {
        //创建RedisTemplate对象
        RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
        //设置连接工厂
        redisTemplate.setConnectionFactory(connectionFactory);
        //创建key的序列化
        redisTemplate.setKeySerializer(RedisSerializer.string());
        redisTemplate.setHashKeySerializer(RedisSerializer.string());
        //创建value的序列化
        redisTemplate.setValueSerializer(RedisSerializer.json());
        redisTemplate.setHashValueSerializer(RedisSerializer.json());
        return redisTemplate;
    }
}

测试结果:

 

 StringRedisTemplate

 

@SpringBootTest
class StringRedisTests {

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    private static final ObjectMapper mapper = new ObjectMapper();

    @Test
    void testString() {
        stringRedisTemplate.opsForValue().set("name", "李四");
        String value = stringRedisTemplate.opsForValue().get("name");
        System.out.println(value);
    }
    @Test
    void testSaveUser() throws JsonProcessingException {
        User user = new User("lisi", 23);
        stringRedisTemplate.opsForValue().set("user:1", mapper.writeValueAsString(user));
        String userStr = stringRedisTemplate.opsForValue().get("user:1");
        System.out.println(mapper.readValue(userStr, User.class));
    }
}