Java的Properties文件操作类

package cn.edu.hbcit.util;
/** 
 * <p>Description: Properties文件操作</p> 
 * 
 * <p>Copyright: Copyright (c) 2009</p> 
 * 
 */  
import java.io.BufferedInputStream;  
import java.io.FileInputStream;  
import java.io.FileOutputStream;  
import java.io.IOException;  
import java.io.InputStream;  
import java.io.OutputStream;  
import java.util.Enumeration;  
import java.util.Properties;  

public class OperateProperties {
	
public OperateProperties(){
		
	}

	//根据key读取value
	 public static String readValue(String filePath,String key) {
	  Properties props = new Properties();
	        try {
	         //InputStream in = new BufferedInputStream (new FileInputStream(filePath));
	        	InputStream in = OperateProperties.class.getResourceAsStream(filePath);
	        	props.load(in);
	        	String value = props.getProperty (key);
	            System.out.println("key:"+key+"   "+"value:"+value);
	            return value;
	        } catch (Exception e) {
	         e.printStackTrace();
	         return null;
	        }
	 }
	 
	//读取properties的全部信息
	    public static void readProperties(String filePath) {
	     Properties props = new Properties();
	        try {
	         InputStream in = new BufferedInputStream (new FileInputStream(filePath));
	         props.load(in);
	            Enumeration en = props.propertyNames();
	             while (en.hasMoreElements()) {
	              String key = (String) en.nextElement();
	                    String Property = props.getProperty (key);
	                    System.out.println(key+Property);
	                }
	        } catch (Exception e) {
	         e.printStackTrace();
	        }
	    }
	    
	  //写入properties信息
	    public static void writeProperties(String filePath,String parameterName,String parameterValue) {
	     Properties prop = new Properties();
	     try {
	      InputStream fis = new FileInputStream(filePath);
	            //从输入流中读取属性列表（键和元素对）
	            prop.load(fis);
	            //调用 Hashtable 的方法 put。使用 getProperty 方法提供并行性。
	            //强制要求为属性的键和值使用字符串。返回值是 Hashtable 调用 put 的结果。
	            OutputStream fos = new FileOutputStream(filePath);
	            prop.setProperty(parameterName, parameterValue);
	            //以适合使用 load 方法加载到 Properties 表中的格式，
	            //将此 Properties 表中的属性列表（键和元素对）写入输出流
	            prop.store(fos, "Update '" + parameterName + "' value");
	        } catch (IOException e) {
	         System.err.println("Visit "+filePath+" for updating "+parameterName+" value error");
	        }
	    }

}