Let us implement another way of object caching through these steps:

1. Aside from logging and auditing, aspects can also be used to trigger caching. To enable Ehcache in Spring 5.0, include the following Maven dependency in the pom.xml:

<dependency> 
    <groupId>net.sf.ehcache</groupId> 
    <artifactId>ehcache</artifactId> 
    <version>3.3.1</version> 
</dependency> 

2. Define all the caches to be used by the application in an XML file named ehcache.xml. Place this configuration file in src/main/resources:

<?xml version="1.0" encoding="UTF-8"?> 
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
  xsi:noNamespaceSchemaLocation="ehcache.xsd" 
  updateCheck="true" 
  monitoring="autodetect" 
  dynamicConfig="true"> 
 
  <diskStore path="C://ch05cached" /> 
 
  <cache name="employeesCache" 
    maxEntriesLocalHeap="500" 
    maxEntriesLocalDisk="500" 
    eternal="false" 
    diskSpoolBufferSizeMB="20" 
    timeToIdleSeconds="300" timeToLiveSeconds="600" 
    memoryStoreEvictionPolicy="LFU" 
    transactionalMode="off"> 
    <persistence strategy="localTempSwap" /> 
  </cache> 
</ehcache> 

3. Open the SpringDispatcherConfig in org.packt.aop.transaction.dispatcher and initialize the following org.springframework.cache.ehcache.EhCacheManagerFactoryBean and org.springframework.cache.CacheManager beans to the container:

import org.springframework.cache.CacheManager; 
import org.springframework.cache.ehcache.EhCacheCacheManager; 
import org.springframework.cache.ehcache.EhCacheManagerFactoryBean; 
// refer to sources 
@EnableWebMvc 
@ComponentScan(basePackages="org.packt.aop.transaction") 
@PropertySource("classpath:config/jdbc.properties") 
@Configuration 
public class SpringDispatcherConfig extends 
      WebMvcConfigurerAdapter{ 
   
@Inject 
private ResourceLoader resourceLoader; 
 
// refer to sources 
  @Bean 
  public CacheManager cacheManager(){ 
    CacheManager cm = new EhCacheCacheManager( 
      ehCacheCacheManager().getObject()); 
    return cm; 
  } 
 
  @Bean 
  public EhCacheManagerFactoryBean ehCacheCacheManager() { 
    EhCacheManagerFactoryBean cmfb = 
        new EhCacheManagerFactoryBean(); 
    cmfb.setConfigLocation(resourceLoader 
      .getResource("classpath:ehcache.xml")); 
    cmfb.setShared(true); 
    return cmfb; 
  } 
}

4. Create an @Aspect that will intercept the getEmployees() method in EmployeeDaoImpl and will manage the caching of its return value, which is a List<Employee>:

import net.sf.ehcache.Cache; 
import net.sf.ehcache.CacheManager; 
import net.sf.ehcache.Element; 
  // refer to sources 
@Component 
@Aspect 
public class CacheListenerAspect { 
   
  @Autowired 
  private CacheManager cacheManager; 
   
  private Logger logger = 
    Logger.getLogger(CacheListenerAspect.class); 
     
  @Around("execution(* org.packt.aop.transaction.dao 
  .impl.EmployeeDaoImpl.getEmployees(..))") 
  public Object cacheMonitor(ProceedingJoinPoint joinPoint) 
    throws Throwable  { 
 
     logger.info("executing " + 
      joinPoint.getSignature().getName()); 
     Cache cache = cacheManager.getCache("employeesCache"); 
    
     logger.info("cache detected is  " + cache.getName()); 
     logger.info("begin caching....."); 
     String key = joinPoint.getSignature().getName(); 
     logger.info(key); 
     if(cache.get(key) == null){ 
       logger.info("caching new Object....."); 
       Object result = joinPoint.proceed(); 
       cache.put(new Element(key, result));      
       return result; 
     }else{ 
       logger.info("getting cached Object....."); 
       return cache.get(key).getObjectValue(); 
     } 
  } 
} 

5. Save all files. Stop the Tomcat server first and then start it again due to cache installation. Then clean, build, and deploy the project.