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");  
            }  
        }  
  
}