java读写消息资源文件

package com.lwf.util;

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Enumeration;
import java.util.Properties;

/*
 * 从路径中的属性文件中读取单个属性或全部属性及设置属性
 */
public class GetProperty {
    public static String readValue(String filePath,String key){
        Properties props = new Properties();
        try {
            InputStream ips = new BufferedInputStream(new FileInputStream(filePath));
            props.load(ips);
            String value = props.getProperty(key);
            System.out.println(key+"="+value);
            return value;
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            return null;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
        
    }

    //读取全部信息
    public static void readProperties(String filePath) {
        Properties props = new Properties();
        try {
            InputStream ips = new BufferedInputStream(new FileInputStream(filePath));
            props.load(ips);
            Enumeration enums = props.propertyNames();
            while(enums.hasMoreElements()){
                String key = (String)enums.nextElement();
                String value = props.getProperty(key);
                System.out.println(key+"="+value);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        
    }
    
    public static void writeProperties(String filePath,String paraKey,String paraValue){
        Properties props = new Properties();
        try {
            
            OutputStream ops = new FileOutputStream(filePath);
            props.setProperty(paraKey, paraValue);
            props.store(ops, "set");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    public static void main(String[] args){
        GetProperty.readValue("D:\\sys.properties", "username");
        
        GetProperty.readProperties("D:\\sys.properties");
        GetProperty.writeProperties("D:\\sys.properties", "age", "21");
    }
}