propertyloader.java

博克后台的开发,有很多使用的方法和例子可以提供给大家学习

package com.common.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FilenameFilter;
import java.io.IOException;
import java.util.Hashtable;
import java.util.Properties;
/**
 * description: 根据提供的路径，将属性文件装载到内存中 
 * 
 * Created on 2005-7-25
 * @author WuQiaoYun
 * 
 */
public class PropertyLoader {
	
  private static Hashtable pptContainer = new Hashtable();
  private static String directory = null;  
 
  /**
   * 通过继承接口FilenameFilter，过滤文件名
   *
   */
  private static class PptFilter implements FilenameFilter {

     public boolean accept(File dir, String name)
     {
         return name.endsWith(extention);
     }

     private String extention;

     public PptFilter(String name)
     {
         extention = "." + name;
     }
 }
    
  public PropertyLoader(){
   	}

  /**
   * 将目录下所有的扩展名是".properties"的文件装载到此类中
   * @param pathname property文件所在目录的绝对路径
   * @return 装载成功，返回true； 反之，返回false
   */
  public static boolean load(String pathname)
  {
     File dir = new File(pathname);
     
     if(!dir.isDirectory()){
         System.out.println("PropertyLoader: (load)Not directory");
         return false;
     }
     
     String names[] = dir.list(new PptFilter("properties"));
     if(names == null){
         System.out.println("PropertyLoader: (load)Haven't properties files");
         return false;
     }
    
     int i = 0;
     directory = dir.getAbsolutePath();

	 String pptname;
	 while (i<names.length) {
	 	pptname = names[i];
	 	int idx = pptname.indexOf(".properties");
	    pptname = pptname.substring(0, idx);
	    FileInputStream fis = null;
	    Properties ppt = null;
	    try
	    {
	    fis = new FileInputStream(directory + File.separatorChar + names[i]);	    
	    ppt = new Properties();
	    
         ppt.load(fis);
         fis.close();
	    }
	    catch(FileNotFoundException e){
          try{
             fis.close();
           }
          catch(IOException e1) {}
            System.out.println("PropertyLoader: (load)" + e.getMessage());
            return false;
	    }
	   catch(IOException ioe) {
	   	 System.out.println("PropertyLoader: (load)" + ioe.getMessage());
	   }
	     pptContainer.put(pptname, ppt);
	     
	     i++;
	 }
	 return true;    
 }
 
  /**
   * 把pathname目录下的所有扩展名为filename的文件加载到到此类中
   * @param pathname：property文件所在目录的绝对路径
   * @param filename：要装载的文件名（不包括后缀.properties）
   * @return 装载成功，返回true； 反之，返回false
   */
  public static boolean load(String pathname, String filename)
  {
     File dir= new File(pathname);
     if(!dir.isDirectory()){
     	System.out.println("PropertyLoader: (load)Not directory");
        return false;
     }
     
     FileInputStream fis;     
     try
     {
     	directory = dir.getAbsolutePath();
        fis = new FileInputStream(directory + File.separatorChar + filename + ".properties");
     }     
     catch(FileNotFoundException fe)
     {
         System.out.println("PropertyLoader: (load)" + fe.getMessage());
         return false;
     }
     
     Properties ppt = new Properties();
     try
     {
         ppt.load(fis);
         fis.close();
     }
     catch(IOException e)
     {
         try
         {
             fis.close();
         }
         catch(IOException e1) {}
         
         System.out.println("PropertyLoader: (load)" + e.getMessage());
         return false;
     }     
     if (pptContainer==null){     	
        System.out.println("PropertyLoader: (load)pptContainer is null");
        return false;	   
     }
     pptContainer.put(filename, ppt);
     return true;          
 }

  /**
   * 在pptname的文件中根据key找到property的值
   * @param pptname：文件名
   * @param key：返回值对应的key值
   * @return 返回对应key的值
   */
  public static String getPptValue(String pptname, String key)
  {
     Properties ppt = (Properties)pptContainer.get(pptname);
     if(ppt == null)
         load(directory);
     return (String)ppt.get(key);
  }

  /**
   * 设置property的值(可用来设定某些目录的路径，例如，下载文件所放置的目录是/WEB_INF/upload，
   * 在pathinfo.properties配置文件中（放置一些目录路径：rootpath，templatepath，uploadpath etc），
   * 找到uploadpath，通过此方法设置uploadpath路径的值为/WEB_INF/upload：
   * setPptValue("pathinfo","uploadpath","/WEB_INF/upload"))
   * 
   * @param pptname：property的文件名
   * @param key：值对应的key 
   * @param value：被设定的值
   * @return true or false
   */
  public static boolean setPptValue(String pptname, String key, String value)
  {
     Properties ppt = (Properties)pptContainer.get(pptname);
     if(ppt == null)
     {
         return false;
     } else
     {
         ppt.put(key, value);
         return true;
     }
  }

  /**
   * 移除pptname文件中key对应的值
   * @param pptname：property的文件名
   * @param key：该值对应的key
   * @return 返回被移除的值
   */
  public static String removePptValue(String pptname, String key)
  {
     Properties ppt = (Properties)pptContainer.get(pptname);
     if(ppt == null)
         return null;
     else
         return (String)ppt.remove(key);
  }

  /**
   * 保存指定目录下的所有property文件
   * @param path：这些property文件的存储目录
   * @param pptName：不带后缀的文件名
   * @return 存储成功返回true；否则，返回false
   */
  public static boolean save(String path, String pptName)
  {
     File dir;
     dir = new File(path);
     if(!dir.isDirectory()){        
        System.out.println("PropertyLoader: (save)Not directory");
        return false;
     }
     
     Properties ppt;
     try
     {
         directory = dir.getAbsolutePath();
     }
     catch(NullPointerException e)
     {
         System.out.println("PropertyLoader: (save)" + e.getMessage());
         return false;
     }
     catch(SecurityException e)
     {
         System.out.println("PropertyLoader: (save)" + e.getMessage());
         return false;
     }
     
     try {
         ppt = (Properties)pptContainer.get(pptName);
         FileOutputStream fos = new FileOutputStream(directory + File.separatorChar + pptName + ".properties");
         if(ppt != null)
             ppt.store(fos, "The properties of " + pptName);
         
         fos.close();
         return true;     
     }catch(FileNotFoundException e) {
     	System.out.println("PropertyLoader: (save)" + e.getMessage());
     	return false;
     }catch(IOException ioe){
     	System.out.println("PropertyLoader: (save)" + ioe.getMessage());
     	return false;
     }
  }

}