Ehcache

Ehcache 2.10 - doc
http://www.ehcache.org/generated/2.10.0/html/ehc-all/#page/Ehcache_Documentation_Set%2Fto-ehcache_online_documentation_library.html%23

Hashtable -> Ehcache

private static Hashtable<String, ControlMemory> hashManager = new Hashtable<String, ControlMemory>();
private static Hashtable<String, String> hashSTBManager = new Hashtable<String, String>();
private static Hashtable<String, String> hashMappingManager = new Hashtable<String, String>();

Basic Caching Problem

- Bad Code Readablity
- Hashtable to Ehcache Method problem.
    [Deffernce]
    Hashtable<K, V>
        get(K)
        put(K,V)
        getKeys() - return Enumeration - hasMoreElements(), nextElement()
        containsKey(String), containsValue(String)
    Ehcache<K, V>
        get(K) - return Object. So needgetObjectValue() or getObjectKey()
        put(new Elemnet(K,V))
        getKeys() - return List - iterator().hasNext(), iterator().next()
        isKeyInCache(String), isValueInCache(String)
- Proto type of EhcacheManager class : Occuered NullPointerException when used [getCache, get, put, etc .. ] in other class

package com.d.n.cacheManager;

import java.util.Arrays;

import net.sf.ehcache.Cache;

import net.sf.ehcache.CacheManager;

import net.sf.ehcache.Ehcache;

import net.sf.ehcache.Element;

import com.d.n.control.ControlMemory;

public class EhCacheManager {

CacheManager cacheManager;

Cache pollingManager, hashManager, hashSTBManager, hashMappingManager;

// private static Hashtable<String, ControlMemory> hashManager = new Hashtable<String, ControlMemory>();  // Key: PairingID, Value: ControlMemory

// private static Hashtable<String, String> hashSTBManager = new Hashtable<String, String>();  // Key: STBID, Value: PairingID

// private static Hashtable<String, String> hashMappingManager = new Hashtable<String, String>();  // Key: PairingID, Value: STBID

public EhCacheManager()

{

cacheManager = CacheManager.newInstance(); // == CacheManager.create();

// String[] cacheNames = CacheManager.getInstance().getCacheNames(); 

pollingManager = cacheManager.getCache("pollingManager");

hashManager = cacheManager.getCache("hashManager");

hashSTBManager = cacheManager.getCache("hashSTBManager");

hashMappingManager = cacheManager.getCache("hashMappingManager");

// System.out.println("Create Cache --- "+Arrays.toString(cacheManager.getCacheNames()));

}

public Ehcache getPollingManager() {

return cacheManager.getCache("pollingManager");

}

public Ehcache getHashManager() {

return cacheManager.getCache("hashManager");

}

public Ehcache getHashSTBManager() {

return cacheManager.getCache("hashSTBManager");

}

public Ehcache getHashMappingManager() {

return cacheManager.getCache("hashMappingManager");

}

/**

* hashManager Create/Update

* @param pid

* @param cm

*/

public void setHashManager(String pid, ControlMemory cm)

{

// hashManager.put(pid, cm);

// cache.put(new Element("hashManager", hashManager));

getHashManager().put(new Element(pid, cm));

}

public void setHashSTBManager(String stbId, String pid)

{

// hashSTBManager.put(stbId, pid);

// cache.put(new Element("hashSTBManager", hashSTBManager));

getHashSTBManager().put(new Element(stbId, pid));

}

public void setHashMappingManager(String pid, String stbId)

{

// hashMappingManager.put(pid, stbId);

// cache.put(new Element("hashMappingManager", hashMappingManager));

getHashMappingManager().put(new Element(pid, stbId));

}

public void setPollingManager(String strSTBID, Long currentTime)

{

// pollingManager.put(strSTBID, currentTime);

// cache.put(new Element("pollingManager", pollingManager));

getPollingManager().put(new Element(strSTBID, currentTime));

}

////////////

public boolean containsKeyHashSTBManager(String stbId)

{

// return hashSTBManager.containsKey(stbId);

return getHashSTBManager().isElementInMemory(stbId);

}

public boolean containsKeyHashManager(String pid)

{

// return hashManager.containsKey(pid);

return getHashManager().isElementInMemory(pid);

}

public boolean containsKeyHashMappingManager(String pid)

{

// return hashMappingManager.containsKey(pid);

return getHashMappingManager().isElementInMemory(pid);

}

public boolean containsKeypollingManager(String strSTBID)

{

// return pollingManager.containsKey(strSTBID);

return getPollingManager().isElementInMemory(strSTBID);

}

/**

* Cache Read

* @param pid Pairing ID

* @return ControlMemory

*/

public ControlMemory getControlMemory(String pid)

{

// Element element = cache.get(pid);

Element element = getHashManager().get(pid);//hashSTBManager.get(pid); // element = null

ControlMemory cm = (ControlMemory)element.getObjectValue();

return cm;

}

}

Solution
- Use Wrapper class
    EhcacheWrapper<K, V> implements CacheWrapper<K, V>

package com.d.n.cacheManager;

public interface CacheWrapper<K, V> {
void put(K key, V value);
V get(K key);
}

package com.d.n.cacheManager;

import java.util.List;

import net.sf.ehcache.CacheManager;
import net.sf.ehcache.Ehcache;
import net.sf.ehcache.Element;

public class EhcacheWrapper<K, V> implements CacheWrapper<K, V> {
private final String cacheName;
private final CacheManager cacheManager;

public EhcacheWrapper(final String cacheName, final CacheManager cacheManager) { 
        this.cacheName = cacheName; 
        this.cacheManager = cacheManager; 
    }

public Ehcache getCache() {
return cacheManager.getEhcache(cacheName);
}

public void put(K key, V value) {
// TODO Auto-generated method stub
getCache().put(new Element(key, value));
}

public V get(K key) {
// TODO Auto-generated method stub
Element element = getCache().get(key);
if(element != null) {
return (V) element.getObjectValue();
}
return null;
}

public void remove(K Key) {
// TODO Auto-generated method stub
getCache().remove(Key);
}

public List<String> keys() {
// TODO Auto-generated method stub
List<String> keys = getCache().getKeys();
return keys;
}

public boolean containsKey(String strPairingID) {
// TODO Auto-generated method stub
return getCache().isKeyInCache(strPairingID);
}

public boolean containsValue(String strCharID) {
// TODO Auto-generated method stub
return getCache().isValueInCache(strCharID);
}

public int size() {
// TODO Auto-generated method stub
return getCache().getSize();
}

}

How to use in other class

CacheManager cacheManager =  CacheManager.newInstance();

EhcacheWrapper<String, ControlMemory> hashManager = new EhcacheWrapper<String, ControlMemory>("hashManager", cacheManager);
EhcacheWrapper<String, String> hashSTBManager = new EhcacheWrapper<String, String>("hashSTBManager", cacheManager);
EhcacheWrapper<String, String> hashMappingManager = new EhcacheWrapper<String, String>("hashMappingManager", cacheManager);
......

Use Same to Hashtable. Likes hashManager.get() / put / containsKey, Value / keys / remove / etc....