The following example listing shows how a SimpleCacheManager instance is configured:

  

   

    

     <bean id="myCacheManager" class="org.springframework.cache.support.SimpleCacheManager">
    

    

         <property name="caches">
    

    

             <set>
    

    

                 <bean
    

    

                     class="org.springframework.cache.concurrent.ConcurrentMapCacheFactoryBean">
    

    

                     <property name="name" value="fixedDepositList" />
    

    

                 </bean>
    

    

                 <bean
    

    

                     class="org.springframework.cache.concurrent.ConcurrentMapCacheFactoryBean">
    

    

                     <property name="name" value="fixedDeposit" />
    

    

                 </bean>
    

    

             </set>
    

    

         </property>
    

    

     </bean>
    

   

  

Caching annotations - @Cacheable, @CacheEvict and @CachePut

To use caching annotations, you need to configure <annotation-driven> element of Spring’s cache schema, as shown here:

  

   

    <beans . xmlns:cache="http://www.springframework.org/schema/cache"
   

   

        xsi:schemaLocation="..... http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache.xsd">
   

   

        <cache:annotation-driven cache-manager="myCacheManager" />
   

   

        .....
   

   

    </beans>
   

  

@Cacheable annotation on a method indicates that the value returned by the method is cached. The following example listing shows the usage of @Cacheable annotation to cache the value returned by FixedDepositService’s findFixedDepositsByBankAccount method:

  

   

    package sample.spring.chapter07.springbankapp.service; 
   

   

    import org.springframework.cache.annotation.Cacheable; 
   

   

    ..... 
   

   

    @Service(value = "fixedDepositService") 
   

   

    public class FixedDepositServiceImpl implements FixedDepositService { 
   

   

        ..... 
   

   

        @Cacheable(value = { "fixedDepositList" })
   

   

        public List<FixedDepositDetails> findFixedDepositsByBankAccount(int bankAccountId) { 
   

   

            logger.info("findFixedDepositsByBankAccount method invoked"); 
   

   

            return myFixedDepositDao.findFixedDepositsByBankAccount(bankAccountId); 
   

   

        } 
   

   

    }
   

  

In the above example listing, the @Cacheable annotation specifies that the value returned by the findFixedDepositsByBankAccount method is stored in the fixedDepositList cache. It is important to note that @Cacheable annotated method is not invoked if the same set of argument values are passed to the method.

If you want to evict data from the cache when a method is called, annotate the method with the @CacheEvict annotation. The following example listing shows usage of @CacheEvict annotation:

  

   

    package sample.spring.chapter07.springbankapp.service; 
   

   

    import org.springframework.cache.annotation.CacheEvict; 
   

   

    ..... 
   

   

    @Service(value = "fixedDepositService") 
   

   

    public class FixedDepositServiceImpl implements FixedDepositService { 
   

   

        ..... 
   

   

        @CacheEvict(value = { "fixedDepositList" }, allEntries=true, beforeInvocation = true) 
   

   

        public void createFixedDeposit(final FixedDepositDetails fdd) throws Exception { 
   

   

            ..... 
   

   

        } 
   

   

        ..... 
   

   

    }
   

  

The @CacheEvict annotation on the createFixedDeposit method instructs Spring to remove all the cached entries from the cache region named fixedDepositList. The value attribute specifies the cache region from which to evict the cached item, and allEntries attribute specifies whether or not all entries from the specified cache region are evicted.

Spring also provides a @CachePut annotation that indicates that a method is always invoked, and the value returned by the method is put into the cache.

Download samples.zip from here and refer to ch07-springbankapp project that shows the usage of Spring's cache abstraction.