Spring Boot Cache Implementation for Database Operations

7 min readDec 2, 2019

Cache implementation was done using built-in cache function on spring boot framework.

First, you need to add the following maven dependency:

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

To enable caching, add @EnableCaching annotation on any configuration class, for example the main class (in this case the DemoApplication class).

Other way of enabling cache is by using XML configuration:

<beans>
    <cache:annotation-driven />
 
    <bean id="cacheManager" class="org.springframework.cache.support.SimpleCacheManager">
        <property name="caches">
            <set>
                <bean
                  class="org.springframework.cache.concurrent.ConcurrentMapCacheFactoryBean"
                  name="addresses"/>
            </set>
        </property>
    </bean>
</beans>

Caching with spring boot is much simpler by using annotations:

@Cacheable

enable caching on a method, usage: @Cacheable(“cacheName”). For multiple cache: @Cacheable({“cacheName1”, “cacheName2”})
More: https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/cache/annotation/Cacheable.html

@CacheEvict

to remove one or more values of cache, usage: @CacheEvict(value=”cacheName”, allEntries=true) → will delete all entries of cache with name “cacheName”
More: https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/cache/annotation/CacheEvict.html

@CachePut

used to add or update the particular cache entries whenever they are altered, for example because of database insert or update syntax
@CachePut(value=”cacheName”) → update cache entry with the name “cacheName”
the difference with @Cacheable is cacheable will skip running the method if the particular cache is available, while cacheput will run the method and put the result in the cache
More: https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/cache/annotation/CachePut.html

@Caching

this annotation is used for a method with multiple annotation of the same type, for example you want to delete two different cache with @CacheEvict annotation
@Caching(evict = {
@CacheEvict(“addresses”),
@CacheEvict(value=”directory”, key=”#customer.name”) })
More: https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/cache/annotation/Caching.html

@CacheConfig

enable cache configuration at the class level. Usage: @CacheConfig(cacheNames={“cacheName”}) → this will make all cache in that class to have a default name of “cacheName”, so at method level, you can just add @Cacheable without specifying the cache name
More: https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/cache/annotation/CacheConfig.html

Conditional caching elements: condition, key, unless

@CacheEvict(value=”cacheName”, condition=#customer.name == ‘Herianto’”) → delete cache entry with the name “cacheName” if the customer name is “Herianto”
@Cacheable(value = “addresses”, key = “#customer.name”) → save method result of customer name with cache name of “addresses”
@CachePut(value=”addresses”, unless=”#result.length() < 64") → update cache entry with the name “addresses” except/unless result length is less than 64
Unlike “condition”, “unless” is evaluated after the method has been called and can therefore refer to the result

To implement cache, we create a simple project with the following classes and configuration:

PeopleController

/all : select all people on DB
/id : select people by id
/update: insert or update (if request has id) to people table
/flush: delete all cache

PeopleService

findAll() : select all people and save result to cache “findAllCache”
savePeople() : save or insert people and delete all cache
findById() : select people by id and save result to cache “findByIdCache”
flushCache() : delete all cache

PeopleRepository

People (entity)

PeopleDto

PeopleMapper

Mapper class by using mapstruct annotation @Mapper

Add @EnableCaching annotation in main class

application.properties

“logging.level.org.springframework.cache” is set to TRACE to see cache logging

Data example in database. Table name: people.

Cache implementation is simulated using API hit steps (with system log below separated by “ — — — — — — “):

/all (no cache, hit DB)
/all (cached, doesn’t hit DB)
/id (no cache)
/id (cached)
/flush (delete all cache)
/id (no cache)
/insert (insert new people, delete cache)
/insert (update people, delete cache)
/all (no cache)

2019-11-29 16:04:57.790 TRACE 2340 --- [nio-8080-exec-9] o.s.cache.interceptor.CacheInterceptor   : Computed cache key 'SimpleKey []' for operation Builder[public java.util.List com.example.demo.service.PeopleService.findAll()] caches=[findAllCache] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'2019-11-29 16:04:57.791 TRACE 2340 --- [nio-8080-exec-9] o.s.cache.interceptor.CacheInterceptor   : No cache entry for key 'SimpleKey []' in cache(s) [findAllCache]2019-11-29 16:04:57.791 TRACE 2340 --- [nio-8080-exec-9] o.s.cache.interceptor.CacheInterceptor   : Computed cache key 'SimpleKey []' for operation Builder[public java.util.List com.example.demo.service.PeopleService.findAll()] caches=[findAllCache] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'2019-11-29 16:04:57.791  INFO 2340 --- [nio-8080-exec-9] com.example.demo.service.PeopleService   : Connecting to DB...
— — — — — —2019-11-29 16:05:00.812 TRACE 2340 --- [nio-8080-exec-1] o.s.cache.interceptor.CacheInterceptor   : Computed cache key 'SimpleKey []' for operation Builder[public java.util.List com.example.demo.service.PeopleService.findAll()] caches=[findAllCache] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'2019-11-29 16:05:00.812 TRACE 2340 --- [nio-8080-exec-1] o.s.cache.interceptor.CacheInterceptor   : Cache entry for key 'SimpleKey []' found in cache 'findAllCache'
— — — — — —2019-11-29 16:05:21.767 TRACE 2340 --- [nio-8080-exec-2] o.s.cache.interceptor.CacheInterceptor   : Computed cache key '23' for operation Builder[public com.example.demo.dto.PeopleDto com.example.demo.service.PeopleService.findById(java.lang.Long)] caches=[findByIdCache] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'2019-11-29 16:05:21.768 TRACE 2340 --- [nio-8080-exec-2] o.s.cache.interceptor.CacheInterceptor   : No cache entry for key '23' in cache(s) [findByIdCache]2019-11-29 16:05:21.768 TRACE 2340 --- [nio-8080-exec-2] o.s.cache.interceptor.CacheInterceptor   : Computed cache key '23' for operation Builder[public com.example.demo.dto.PeopleDto com.example.demo.service.PeopleService.findById(java.lang.Long)] caches=[findByIdCache] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'2019-11-29 16:05:21.768  INFO 2340 --- [nio-8080-exec-9] com.example.demo.service.PeopleService   : Connecting to DB...
— — — — — —2019-11-29 16:05:25.476 TRACE 2340 --- [nio-8080-exec-3] o.s.cache.interceptor.CacheInterceptor   : Computed cache key '23' for operation Builder[public com.example.demo.dto.PeopleDto com.example.demo.service.PeopleService.findById(java.lang.Long)] caches=[findByIdCache] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'2019-11-29 16:05:25.476 TRACE 2340 --- [nio-8080-exec-3] o.s.cache.interceptor.CacheInterceptor   : Cache entry for key '23' found in cache 'findByIdCache'
— — — — — —2019-11-29 16:05:29.145  INFO 2340 --- [nio-8080-exec-4] com.example.demo.service.PeopleService   : Flushing cache with name: findAllCache2019-11-29 16:05:29.146  INFO 2340 --- [nio-8080-exec-4] com.example.demo.service.PeopleService   : Flushing cache with name: findByIdCache
— — — — — —2019-11-29 16:05:31.657 TRACE 2340 --- [nio-8080-exec-5] o.s.cache.interceptor.CacheInterceptor   : Computed cache key '23' for operation Builder[public com.example.demo.dto.PeopleDto com.example.demo.service.PeopleService.findById(java.lang.Long)] caches=[findByIdCache] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'2019-11-29 16:05:31.657 TRACE 2340 --- [nio-8080-exec-5] o.s.cache.interceptor.CacheInterceptor   : No cache entry for key '23' in cache(s) [findByIdCache]2019-11-29 16:05:31.657 TRACE 2340 --- [nio-8080-exec-5] o.s.cache.interceptor.CacheInterceptor   : Computed cache key '23' for operation Builder[public com.example.demo.dto.PeopleDto com.example.demo.service.PeopleService.findById(java.lang.Long)] caches=[findByIdCache] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'
— — — — — —2019-11-29 16:05:37.333  INFO 2340 --- [nio-8080-exec-6] com.example.demo.service.PeopleService   : Inserting new people...2019-11-29 16:05:37.348 TRACE 2340 --- [nio-8080-exec-6] o.s.cache.interceptor.CacheInterceptor   : Invalidating entire cache for operation Builder[public com.example.demo.dto.PeopleDto com.example.demo.service.PeopleService.savePeople(com.example.demo.dto.PeopleDto)] caches=[findAllCache] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='',true,false on method public com.example.demo.dto.PeopleDto com.example.demo.service.PeopleService.savePeople(com.example.demo.dto.PeopleDto)2019-11-29 16:05:37.348 TRACE 2340 --- [nio-8080-exec-6] o.s.cache.interceptor.CacheInterceptor   : Invalidating entire cache for operation Builder[public com.example.demo.dto.PeopleDto com.example.demo.service.PeopleService.savePeople(com.example.demo.dto.PeopleDto)] caches=[findByIdCache] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='',true,false on method public com.example.demo.dto.PeopleDto com.example.demo.service.PeopleService.savePeople(com.example.demo.dto.PeopleDto)
— — — — — —2019-11-29 16:05:49.041  INFO 2340 --- [nio-8080-exec-7] com.example.demo.service.PeopleService   : Updating people...2019-11-29 16:05:49.149 TRACE 2340 --- [nio-8080-exec-7] o.s.cache.interceptor.CacheInterceptor   : Invalidating entire cache for operation Builder[public com.example.demo.dto.PeopleDto com.example.demo.service.PeopleService.savePeople(com.example.demo.dto.PeopleDto)] caches=[findAllCache] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='',true,false on method public com.example.demo.dto.PeopleDto com.example.demo.service.PeopleService.savePeople(com.example.demo.dto.PeopleDto)2019-11-29 16:05:49.150 TRACE 2340 --- [nio-8080-exec-7] o.s.cache.interceptor.CacheInterceptor   : Invalidating entire cache for operation Builder[public com.example.demo.dto.PeopleDto com.example.demo.service.PeopleService.savePeople(com.example.demo.dto.PeopleDto)] caches=[findByIdCache] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='',true,false on method public com.example.demo.dto.PeopleDto com.example.demo.service.PeopleService.savePeople(com.example.demo.dto.PeopleDto)
— — — — — —2019-11-29 16:05:54.770 TRACE 2340 --- [nio-8080-exec-8] o.s.cache.interceptor.CacheInterceptor   : Computed cache key 'SimpleKey []' for operation Builder[public java.util.List com.example.demo.service.PeopleService.findAll()] caches=[findAllCache] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'2019-11-29 16:05:54.770 TRACE 2340 --- [nio-8080-exec-8] o.s.cache.interceptor.CacheInterceptor   : No cache entry for key 'SimpleKey []' in cache(s) [findAllCache]2019-11-29 16:05:54.770 TRACE 2340 --- [nio-8080-exec-8] o.s.cache.interceptor.CacheInterceptor   : Computed cache key 'SimpleKey []' for operation Builder[public java.util.List com.example.demo.service.PeopleService.findAll()] caches=[findAllCache] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'2019-11-29 16:05:54.770  INFO 2340 --- [nio-8080-exec-8] com.example.demo.service.PeopleService   : Connecting to DB...