propertiesmanager.java

java三层架构（MVC)实现的在线图书销售系统。其中应用到工厂

package accp.yyw.model.tool;

import java.io.FileNotFoundException;
import java.util.Hashtable;
import java.util.Properties;

/**
 * <p>Title: BookShop</p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2005</p>
 * <p>Company: accp</p>
 * @author yyw
 * @version 1.0
 */

public class PropertiesManager {

          private static Hashtable propertycache;

          private static java.lang.Object propertiesloaderlock;

          static {

            propertiesloaderlock = new Object();
    }

          public PropertiesManager() {

            super();
          }

          public static java.util.Properties getProperties(String propertiesfilename) throws java.io.FileNotFoundException {

                  synchronized (propertiesloaderlock) {

                    if (propertycache == null || propertycache.get(propertiesfilename) == null) {

                              propertycache = new Hashtable();

                              propertycache.put(propertiesfilename,new PropertiesLoader().getProperties(propertiesfilename));
                    }
                  }

                return (Properties) propertycache.get(propertiesfilename);
        }

          public static void resetPropertiesManager() {

            propertycache = null;
          }
}