spring boot cache not support kotlin?

Question

I'm try to replace some java code with kotlin.

Such as jpa or cache.

The Start class is:

@EnableAsync
@EnableCaching
@EnableSwagger2
@SpringBootApplication
open class Application

fun main(args: Array<String>) {
    SpringApplication.run(Application::class.java)
}

The simple controller:

@RestController
class CacheController {

    @Autowired
    private lateinit var cache: CacheService

    @PutMapping("{id}")
    fun save(@PathVariable id: Long) {
        cache.save(id)
    }
}

CacheService:

@Component
@CacheConfig(cacheNames = arrayOf("longCacheManager"), cacheManager = "longCacheManager")
open class CacheService {

    @Cacheable(key = "#id")
    fun save(id: Long): Long {
        return id
    }
}

cacheManager:

@Configuration
open class CacheConfig {

    @Autowired
    private lateinit var redisConnectionFactory: RedisConnectionFactory

    @Bean
    @Qualifier("longCacheManager")
    open fun longCacheManager(): CacheManager {
        val redisTemplate = StringRedisTemplate(redisConnectionFactory)
        redisTemplate.valueSerializer = GenericToStringSerializer(Long::class.java)
        val cacheManager = RedisCacheManager(redisTemplate)
        cacheManager.setUsePrefix(true)
        return cacheManager
    }
}

I can confirm the parameter of id entered in CacheService's method save, but after I have excute the PutMethod, there is nothing in redis.

When I write the cacheServie with java like this, the redis would be save what I want.

The Java cache service like this:

@Component
@CacheConfig(cacheNames = "longCacheManager", cacheManager = "longCacheManager")
public class JavaCacheService {

    @Cacheable(key = "#id")
    public Long save(Long id) {
        return id;
    }
}

I have also read some article like this: https://pathtogeek.com/spring-boot-caching-with-kotlin

My SpringBootVersion is 1.5.3.RELEASE and kotlinVersion is 1.1.3-2

Answer 1

Thanks all, I have fix it by make the cache method open

@Component
@CacheConfig(cacheNames = arrayOf("longCacheManager"), cacheManager = "longCacheManager")
open class CacheService {

    @Cacheable(key = "#id.toString()")
    open fun save(id: Long): Long {
        return id
    }
}

Spring generated proxy with cglib.

It must mandatory inherit the classes and methods.

But kotlin default is final class and method which without the keyword open.