Using EhCache in Spring 4 without XML

Question

Is there a way to initialize EhCache without xml in either Spring 4 or with Spring Boot?

I noticed Spring Boot 1.0.0.RC3 doesn\'t have any ehcache dependencies but t

Answer 1

I do this at two levels of abstraction, a configuration file per technology (Ehcache, Redis, etc.) and a general configuration file.

Here's the one for Ehcache (Redis would be similar):

@Configuration
public class EhCacheConfiguration {

    @Bean
    public EhCacheCacheManager ehCacheCacheManager() {

        return new EhCacheCacheManager(ehCacheManagerFactoryBean().getObject());
    }


    @Bean
    public EhCacheManagerFactoryBean ehCacheManagerFactoryBean() {

        EhCacheManagerFactoryBean cacheManagerFactoryBean = new EhCacheManagerFactoryBean();

        cacheManagerFactoryBean.setConfigLocation(new ClassPathResource("ehcache.xml"));
        cacheManagerFactoryBean.setShared(true);

        return cacheManagerFactoryBean;
    }
}

And here's the general one (complete with Redis hooks):

@Configuration
@EnableCaching
public class CachingConfiguration implements CachingConfigurer {

    @Qualifier("ehCacheCacheManager")
    @Autowired(required = false)
    private CacheManager ehCacheCacheManager;

    @Qualifier("redisCacheManager")
    @Autowired(required = false)
    private CacheManager redisCacheManager;


    @Bean
    @Override
    public CacheManager cacheManager() {

        List<CacheManager> cacheManagers = Lists.newArrayList();

        if (this.ehCacheCacheManager != null) {
            cacheManagers.add(this.ehCacheCacheManager);
        }

        if (this.redisCacheManager != null) {
            cacheManagers.add(this.redisCacheManager);
        }

        CompositeCacheManager cacheManager = new CompositeCacheManager();

        cacheManager.setCacheManagers(cacheManagers);
        cacheManager.setFallbackToNoOpCache(false);

        return cacheManager;
    }


    @Bean
    @Override
    public KeyGenerator keyGenerator() {

        return new DefaultKeyGenerator();
    }
}

Answer 2

XML-less configuration of EhCache in Spring

@Configuration
@EnableCaching
public class CachingConfig implements CachingConfigurer {
    @Bean(destroyMethod="shutdown")
    public net.sf.ehcache.CacheManager ehCacheManager() {
        CacheConfiguration cacheConfiguration = new CacheConfiguration();
        cacheConfiguration.setName("myCacheName");
        cacheConfiguration.setMemoryStoreEvictionPolicy("LRU");
        cacheConfiguration.setMaxEntriesLocalHeap(1000);

        net.sf.ehcache.config.Configuration config = new net.sf.ehcache.config.Configuration();
        config.addCache(cacheConfiguration);

        return net.sf.ehcache.CacheManager.newInstance(config);
    }

    @Bean
    @Override
    public CacheManager cacheManager() {
        return new EhCacheCacheManager(ehCacheManager());
    }

    @Bean
    @Override
    public KeyGenerator keyGenerator() {
        return new SimpleKeyGenerator();
    }

    @Bean
    @Override
    public CacheResolver cacheResolver()    {
        return new SimpleCacheResolver();
    }

    @Bean
    @Override
    public CacheErrorHandler errorHandler() {
         return new SimpleCacheErrorHandler();
    }
}

Alternatively for testing, you can use a simple ConcurrentMapCache running without XML as below.

@Configuration
@EnableCaching
public class CachingConfig implements CachingConfigurer {
    @Bean
    @Override
    public CacheManager cacheManager() {
        SimpleCacheManager cacheManager = new SimpleCacheManager();

        List<Cache> caches = new ArrayList<Cache>();
        caches.add(new ConcurrentMapCache("myCacheName"));
        cacheManager.setCaches(caches);

        return cacheManager;
    }

    @Bean
    @Override
    public KeyGenerator keyGenerator() {
        return new SimpleKeyGenerator();
    }

    @Bean
    @Override
    public CacheResolver cacheResolver()    {
        return new SimpleCacheResolver();
    }

    @Bean
    @Override
    public CacheErrorHandler errorHandler() {
         return new SimpleCacheErrorHandler();
    }
}

Edit: Updated to add shutdown method on underlying cache

Edit: Added configuration for error handler and cache resolver

Edit: changing constructor call on SimpleCacheResolver which resolves CacheManager must not be null issue (Spring v5.1+)

@Configuration
@EnableCaching
public class CachingConfig implements CachingConfigurer {

    public static final String USER_CACHE_INSTANCE = "my-spring-ehcache";
    private final CacheManager cacheManager;
    private final net.sf.ehcache.CacheManager ehCacheManager;


    public CachingConfig() {
        CacheConfiguration cacheConfiguration = new CacheConfiguration();
        cacheConfiguration.setName(USER_CACHE_INSTANCE);
        cacheConfiguration.setMemoryStoreEvictionPolicy("LRU");
        cacheConfiguration.setMaxEntriesLocalHeap(1000);
        net.sf.ehcache.config.Configuration config
                = new net.sf.ehcache.config.Configuration();
        config.addCache(cacheConfiguration);
        this.ehCacheManager = net.sf.ehcache.CacheManager.newInstance(config);
        this.cacheManager = new EhCacheCacheManager(ehCacheManager);
    }

    @Bean(destroyMethod="shutdown")
    public net.sf.ehcache.CacheManager ehCacheManager() {
        return ehCacheManager;
    }

    @Bean
    @Override
    public CacheManager cacheManager() {
        return cacheManager;
    }

    @Bean
    @Override
    public KeyGenerator keyGenerator() {
        return new SimpleKeyGenerator();
    }

    @Bean
    @Override
    public CacheResolver cacheResolver() {
        return new SimpleCacheResolver(cacheManager);
    }

    @Bean
    @Override
    public CacheErrorHandler errorHandler() {
        return new SimpleCacheErrorHandler();
    }
}