cachemanagerimpl.java

JAVA Servlet2.3外文书籍源码

package cache;

import java.util.HashMap;
import java.util.Iterator;

public final class CacheManagerImpl implements ICacheManager {
    
    private static CacheManagerImpl mySelf;
    private HashMap cacheMap = new HashMap();

    /** @link aggregation */
    /*#SimpleCacheImpl lnkSimpleCacheImpl;*/
    
    private CacheManagerImpl() {
        
        Thread th = new Thread(new Runnable() {
            public void run() {
                try {
                    Thread.sleep(60*1000);
                }catch(InterruptedException ex) {
                    throw new RuntimeException(ex.getMessage());
                }
                expire();
            }
        });
        th.setPriority(th.MIN_PRIORITY);
        th.start();
        
    }
    
    public static ICacheManager getInstance() {
        
        if(mySelf == null) {
            synchronized(ICacheManager.class) {
                if(mySelf == null)
                    mySelf = new CacheManagerImpl();
            }
        }
        
        return mySelf;
        
    }
    
    public ICache getCache(String cacheName) {
        
        synchronized(this) {
            return (ICache)cacheMap.get(cacheName);
        }
        
    }
    
    public void addCache(ICache cache) {
        
        synchronized(this) {
            cacheMap.put(cache.getName(), cache);
        }
        
    }
    
    private void expire() {
        
        synchronized(this) {
            Iterator it = cacheMap.values().iterator();
            while(it.hasNext())
                ((ICache)it.next()).expire();
        }
        
    }
        
        
    
}