package ejava.examples.webtier.dao;
   
   import java.util.HashMap;
   import java.util.Iterator;
   
   import org.apache.commons.logging.Log;
   import org.apache.commons.logging.LogFactory;
   
   public class DAOFactory {
      private static Log log = LogFactory.getLog(DAOFactory.class);
      
      private static HashMap<String, DAOTypeFactory> factories = 
          new HashMap<String, DAOTypeFactory>();
      
      public static DAOTypeFactory getDAOTypeFactory() {
          String name=null;
          Iterator<String> itr = factories.keySet().iterator();
          if (itr.hasNext()) {
              name = factories.keySet().iterator().next();
          }
          log.debug("default DAO Factory name=" + name);
          return (name==null) ? null : factories.get(name);
      }
      
      public static DAOTypeFactory getDAOTypeFactory(String name) {
          return (name==null) ? null : factories.get(name);
      }
      
      public static void registerFactoryType(
              String name, DAOTypeFactory typeFactory){
          log.debug("registering DAOTypeFactory:" + name);
          factories.put(name, typeFactory);
      }
  }