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");        }    }}