randomstrategy.java

主要考察的是资源池的设计和实现

package ServerImpl;
import java.util.*;
public class randomStrategy implements Strategy{
    Hashtable unused=null;
    ArrayList list=new ArrayList();
    public Object getObject(String id, ResourcePool pool) throws Exception {     
        Resource rs;
        Object obj;
	Random random=new Random();
        unused=pool.getUnused();
        Enumeration e=unused.keys();
        list.clear();
        while( e.hasMoreElements() ){
            obj = e.nextElement();   
            rs = (Resource)unused.get(obj);
            if(rs.getObjectID().equalsIgnoreCase(id)) list.add(obj);
        }
        if(list.size()==0)
            return null;
        else{
            return list.get(random.nextInt(list.size()));
        }
   }
}