oscachecontroller.java

一个很好的开源项目管理系统源代码

package net.java.workeffort.infrastructure.cache;

import com.opensymphony.oscache.base.CacheEntry;
import com.opensymphony.oscache.base.NeedsRefreshException;
import com.opensymphony.oscache.general.GeneralCacheAdministrator;

/**
 * Implementation of ICacheController for oscache.
 * <p>
 * cacheAdministrator has to be set before an object of this class can be used.
 * Note that this cache is seperate from the cache used by oscache for caching
 * html.
 * @author Antony Joseph
 */
public class OsCacheController implements ICacheController {
    private GeneralCacheAdministrator cacheAdministrator;

    /**
     * Get the object from the cache. A RefreshRequiredException will be thrown
     * when no cache entry is found for the key.When the
     * RefreshRequiredException is thrown the calling thread should either call
     * putObject() or cancelObject() so that oscache can release the lock on the
     * cache entry. This mimicks oscache behavior.
     * <p>
     * oscache's getFromCache() will throw an NeedsRefreshException when no
     * entry is found in the cache. When the exception is thrown, oscache will
     * block other threads from using the key (cache entry) till the current
     * thread sets the cache value using putInCache() or till the current thread
     * calls cancelUpdate() which lets oscache know that the current thread does
     * not intent to set the cache value. See
     * GeneralCacheAdministrator.getFromCache() of oscache.
     * @param key The cache key
     * @throws RefreshRequiredException.
     */
    public Object getObject(String key) throws RefreshRequiredException {
        try {
            // Get from the cache
            return cacheAdministrator.getFromCache(key, CacheEntry.INDEFINITE_EXPIRY);
        }
        catch (NeedsRefreshException nre) {
            throw new RefreshRequiredException(nre);
        }
    }

    public void putObject(String key, Object object) {
        putObject(key, object, new String[] { "net.java.workeffort.oscache.common" });
    }

    public void putObject(String key, Object object, String[] groups) {
        cacheAdministrator.putInCache(key, object, groups);
    }

    public Object removeObject(String key) {
        cacheAdministrator.flushEntry(key);
        return null;
    }

    public void flushGroup(String group) {
        cacheAdministrator.flushGroup(group);
    }

    public void cancelUpdate(String key) {
        cacheAdministrator.cancelUpdate(key);
    }
    
    public void destroy() {
        cacheAdministrator.destroy();
    }
    
    public GeneralCacheAdministrator getCacheAdministrator() {
        return cacheAdministrator;
    }
    
    public void setCacheAdministrator(
            GeneralCacheAdministrator cacheAdministrator) {
        this.cacheAdministrator = cacheAdministrator;
    }
}