poolableobjectfactorysample.java

这是一个关于J2EE的开源包common里的许多组件的示例应用程序,可以借鉴.

/**
 * Title : Base Dict Class
 * Description : here Description is the function of class, here maybe multirows    
 * @author        kevin
 * @Version       1.0 
 */

package pool;

import org.apache.commons.pool.ObjectPool;
import org.apache.commons.pool.ObjectPoolFactory;
import org.apache.commons.pool.PoolableObjectFactory;
import org.apache.commons.pool.impl.StackObjectPoolFactory;

/**
 * Class description goes here.
 * @version 1.0  2005-12-5 
 * @author kevin
 */
public class PoolableObjectFactorySample implements PoolableObjectFactory
{

	private static int counter = 0;

	public Object makeObject() throws Exception
	{
		Object obj = String.valueOf(counter++);
		System.err.println("Making Object " + obj);
		return obj;
	}

	public void activateObject(Object obj) throws Exception
	{
		System.err.println("Activating Object " + obj);
	}

	public void passivateObject(Object obj) throws Exception
	{
		System.err.println("Passivating Object " + obj);
	}

	public boolean validateObject(Object obj)
	{
		/* 以1/2的概率将对象判定为失效 */
		boolean result = (Math.random() > 0.5);
		System.err.println("Validating Object " + obj + " : " + result);
		return result;
	}

	public void destroyObject(Object obj) throws Exception
	{
		System.err.println("Destroying Object " + obj);
	}
	
	public static void main(String[] args) {
        Object obj = null;
        PoolableObjectFactory factory
                = new PoolableObjectFactorySample();
        ObjectPoolFactory poolFactory
                = new StackObjectPoolFactory(factory);
        ObjectPool pool = poolFactory.createPool();
        try {
            for(long i = 0; i < 10 ; i++) {
                System.out.println("== " + i + " ==");
                obj = pool.borrowObject();
                System.out.println(obj);
                pool.returnObject(obj);
            }
            obj = null;
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        finally {
            try{
                if (obj != null) {
                    pool.returnObject(obj);
                }
                pool.close();
            }
            catch (Exception e){
                e.printStackTrace();
            }
        }
    }

}