I have already accepted answer given by @ragnor. But I think I should post a complete example here which has worked for me.
- Make sure you have cache-enabled for your application by adding @EnableCaching
- POM.xml should have following dependency:
<dependency>
<groupId>com.google.code.simple-spring-memcached</groupId>
<artifactId>spring-cache</artifactId>
<version>3.6.1</version>
</dependency>
<dependency>
<groupId>com.google.code.simple-spring-memcached</groupId>
<artifactId>spymemcached-provider</artifactId>
<version>3.6.1</version>
</dependency>
- Add a config file to configure your memcached cache configuration, say MySSMConfig.java
@Configuration
@EnableAspectJAutoProxy
@ImportResource("simplesm-context.xml") // This line may or may not be needed,
// not sure
public class SSMConfig
{
private String _memcachedHost; //Machine where memcached is running
private int _memcachedPort; //Port on which memcached is running
@Bean
public CacheManager cacheManager()
{
//Extended manager used as it will give custom-expiry value facility in future if needed
ExtendedSSMCacheManager ssmCacheManager = new ExtendedSSMCacheManager();
//We can create more than one cache, hence list
List<SSMCache>cacheList = new ArrayList<SSMCache>();
//First cache: Testcache
SSMCache testCache = createNewCache(_memcachedHost, _memcachedPort,
"testcache", 5);
//One more dummy cache
SSMCache dummyCache = createNewCache(_memcachedHost,_memcachedPort,
"dummycache", 300);
cacheList.add(testCache);
cacheList.add(dummyCache);
//Adding cache list to cache manager
ssmCacheManager.setCaches(cacheList);
return ssmCacheManager;
}
//expiryTimeInSeconds: time(in seconds) after which a given element will expire
//
private SSMCache createNewCache(String memcachedServer, int port,
String cacheName, int expiryTimeInSeconds)
{
//Basic client factory to be used. This is SpyMemcached for now.
MemcacheClientFactoryImpl cacheClientFactory = new MemcacheClientFactoryImpl();
//Memcached server address parameters
//"127.0.0.1:11211"
String serverAddressStr = memcachedServer + ":" + String.valueOf(port);
AddressProvider addressProvider = new DefaultAddressProvider(serverAddressStr);
//Basic configuration object
CacheConfiguration cacheConfigToUse = getNewCacheConfiguration();
//Create cache factory
CacheFactory cacheFactory = new CacheFactory();
cacheFactory.setCacheName(cacheName);
cacheFactory.setCacheClientFactory(cacheClientFactory);
cacheFactory.setAddressProvider(addressProvider);
cacheFactory.setConfiguration(cacheConfigToUse);
//Get Cache object
Cache object = null;
try {
object = cacheFactory.getObject();
} catch (Exception e) {
}
//allow/disallow remove all entries from this cache!!
boolean allowClearFlag = false;
SSMCache ssmCache = new SSMCache(object, expiryTimeInSeconds, allowClearFlag);
return ssmCache;
}
private CacheConfiguration getNewCacheConfiguration()
{
CacheConfiguration ssmCacheConfiguration = new CacheConfiguration();
ssmCacheConfiguration.setConsistentHashing(true);
//ssmCacheConfiguration.setUseBinaryProtocol(true);
return ssmCacheConfiguration;
}
}
- OK, we are ready to use our configured cache.
- Sample methods in some other class to read from cache and to remove from cache
@Cacheable(value="dummycache, key="#givenId.concat('-dmy')", unless="#result == null")
public String getDummyDataFromMemCached(String givenId)
{
logger.warn("getDummyDataFromMemCached: Inside DUMMY method to actually get data");
return "Sample-" + String.valueOf(givenId);
}
@CacheEvict(value="dummycache",key="#givenId.concat('-dmy')")
public void removeDummyDataFromMemCached(String givenId)
{
//Do nothing
return;
}
Note that we have added suffix to the kache-keys. As Memcached does not support cache-zones, "dummycache" and "testcache" ultimately does not remain separate on a single server. (They may remain separate with some other cache implementation). Hence to avoid conflict, we append unique suffix to the cache-key.
If you want to cache objects of your own class, then make sure that they are serializable. Just change your class definition to 'XYZ implements Serializable'.
