RedisTemplatを使った簡単な分散ロックの実装の話

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

@Configuration
public class RedisConfig {
    @Bean
    public RedisTemplate<String , Object> redisTemplate(RedisConnectionFactory redisConnectionFactory){
        RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
        //String type key serializer
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        //String type value serializer
        redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());
        //Hash type key serializer
        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        //Hash type value serializer
        redisTemplate.setHashValueSerializer(new GenericJackson2JsonRedisSerializer());
        //Inject the connection factory
        redisTemplate.setConnectionFactory(redisConnectionFactory);
        return redisTemplate;
    }
 }

@SpringBootTest
class ApplicationTests {
    @Autowired
    private RedisTemplate redisTemplate;
	@Test
	public void lodsTest01(){
		ValueOperations valueOperations = redisTemplate.opsForValue();
	        // create a placeholder, if the key does not exist to set success
	        Boolean isLock = valueOperations.setIfAbsent("k1", "v1");
	        //If the occupancy is successful, do the normal operation
	        if (isLock){
	        	//set a name to store in redis
	            valueOperations.set("name","xxxx");
	            // Retrieve the name from redis
	            String name = (String) valueOperations.get("name");
	            System.out.println("name = " + name);
	            //Manually create exceptions
	            Integer.parseInt("xxxx");
	            //delete the lock at the end of the operation
	            redisTemplate.delete("k1");
	        }else{
	            System.out.println("A thread is in use, please try later");
	        }
	}
}

	@Test
    public void testLock02() {
        ValueOperations valueOperations = redisTemplate.opsForValue();
        // If the key does not exist before you can set the success, set a valid time to prevent thread exceptions deadlock
        Boolean isLock = valueOperations.setIfAbsent("k1", "v1",5, TimeUnit.SECONDS);
        //If the occupancy is successful, proceed to normal operation
        if (isLock){
        	//set a name to store in redis
            valueOperations.set("name","xxxx");
            // Retrieve the name from redis
            String str = (String) valueOperations.get("name");
            System.out.println("name = " + str);
            // Create exception
            Integer.parseInt("xxxx");
            //delete the lock at the end of the operation
            redisTemplate.delete("k1");
        }else{
            System.out.println("A thread is in use, please try later");
        }
    }


solution :

if redis.call("get",KEYS[1])==ARGV[1] then
    return redis.call("del",KEYS[1])
else
    return 0
end

	@Bean
    public DefaultRedisScript<Boolean> defaultRedisScript(){
        DefaultRedisScript<Boolean> redisScript = new DefaultRedisScript<>();
        //lock.lua script location is the same level as application.yml
        redisScript.setLocation(new ClassPathResource("lock.lua"));
        // set the type to boolean
        redisScript.setResultType(Boolean.class);
        return redisScript;
    }

@Test
    public void testLock03(){
        ValueOperations valueOperations = redisTemplate.opsForValue();
        String value = UUID.randomUUID().toString();
        // If the key does not exist, set the value to a random number to prevent thread insecurity
        Boolean isLock = valueOperations.setIfAbsent("k1", value, 5, TimeUnit.SECONDS);
        //If the occupation is successful, proceed to normal operation 
        if (isLock){
        	//set a name to store in redis
            valueOperations.set("name","xxxx");
            // Retrieve the name from redis
            String name = (String) valueOperations.get("name");
            System.out.println("name = " + name);
            // send lua script for redis to delete the value corresponding to the lock
            Boolean aBoolean = (Boolean) redisTemplate.execute(redisScript, Collections.singletonList("k1"), value);
            System.out.println(aBoolean);
        }else{
            System.out.println("There are threads in use, please try later");
        }
    }


Test results: