Redis分布式锁

package com.sunreal.distribute.util;

import lombok.extern.slf4j.Slf4j;
import org.springframework.data.redis.connection.RedisStringCommands;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.RedisScript;
import org.springframework.data.redis.core.types.Expiration;

import java.util.Arrays;
import java.util.UUID;

/**
 * @author lkz
 * @description Redis分布式锁
 * @date 2021/4/2 21:49
 */
@Slf4j
public class RedisLock {

    private static final RedisTemplate redisTemplate = SpringContext.getBean(StringRedisTemplate.class);

    private String key;
    private String value;
    /**
     * 过期时间-s
     */
    private int expireTime;

    public RedisLock(String key, int expireTime) {
        this.key = key;
        this.value = UUID.randomUUID().toString();
        this.expireTime = expireTime;
    }

    /**
     * 获取分布式锁
     * @return
     */
    public Boolean getLock() {
        RedisCallback<Boolean> redisCallback = redisConnection -> {
            // 设置NX
            RedisStringCommands.SetOption setOption = RedisStringCommands.SetOption.ifAbsent();
            // 设置过期时间
            Expiration expiration = Expiration.seconds(this.expireTime);
            // 序列化key
            byte[] redisKey = redisTemplate.getKeySerializer().serialize(this.key);
            // 序列化value
            byte[] redisValue = redisTemplate.getValueSerializer().serialize(this.value);
            // 执行setnx操作
            return redisConnection.set(redisKey, redisValue, expiration, setOption);
        };
        Boolean result = (Boolean) redisTemplate.execute(redisCallback);
        log.info("Redis加锁的结果: [{}]", result);
        return result;
    }

    /**
     * 解锁
     * @return
     */
    public Boolean unLock() {
        StringBuilder script = new StringBuilder(32);
        script.append("if redis.call(\"get\", KEYS[1]) == ARGV[1] then ")
                .append(" return redis.call(\"del\", KEYS[1]) ")
                .append("else")
                .append(" return 0 ")
                .append("end");
        RedisScript<Boolean> redisScript = RedisScript.of(script.toString(), Boolean.class);
        Boolean result = (Boolean) redisTemplate.execute(redisScript, Arrays.asList(key), value);

        log.info("Redis释放锁的结果: [{}]", result);
        return result;
    }
}

```java
package com.sunreal.core.redis;

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.jsontype.impl.LaissezFaireSubTypeValidator;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import org.redisson.Redisson;
import org.redisson.config.Config;
import org.springframework.cache.annotation.CachingConfigurerSupport;
import org.springframework.cache.annotation.EnableCaching;
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.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

/**
 * @author lkz
 * @describe
 * @date 2021/9/5 17:20
 */
@EnableCaching
@Configuration
public class RedisConfig extends CachingConfigurerSupport {

    @Bean
    @SuppressWarnings(value = {"unchecked", "rawtypes"})
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
        redisTemplate.setConnectionFactory(factory);

        Jackson2JsonRedisSerializer serializer = new Jackson2JsonRedisSerializer(Object.class);

        ObjectMapper mapper = new ObjectMapper();
        mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        mapper.activateDefaultTyping(
                LaissezFaireSubTypeValidator.instance,
                ObjectMapper.DefaultTyping.NON_FINAL,
                JsonTypeInfo.As.PROPERTY);
        // 解决jackson2无法反序列化LocalDateTime的问题
        mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
        mapper.registerModule(new JavaTimeModule());
        serializer.setObjectMapper(mapper);
        // 使用StringRedisSerializer来序列化和反序列化redis的key值
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        redisTemplate.setValueSerializer(serializer);

        // Hash的key也采用StringRedisSerializer的序列化方式
        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        redisTemplate.setHashValueSerializer(serializer);

        redisTemplate.setDefaultSerializer(serializer);
        return redisTemplate;
    }


    @Bean
    public Redisson redisson() {
        Config config = new Config();
        config.useSingleServer()
                .setAddress("redis://x.x.x:6379")
                .setPassword("xxx")
                .setDatabase(0);
        return (Redisson) Redisson.create(config);
    }
}