学步园

首先定义一个properties文件：test.properties

路径为D:/dev_env/workspace/test/WebRoot/WEB-INF/classes/test.properties

url=url0
username=username0
password=password0

定义操作类OperationPropertiesFile.java：

/**
 * 
 */
package com.adam.dev.test.properties;

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

/**
 * @author adam.胡升阳
 * 创建日期 2011-11-4
 */
public class OperationPropertiesFile {
	
	//读取properties文件信息 
	public static void readPropertiesFile(String filePath){
		try {
			InputStream is = new BufferedInputStream(new FileInputStream(filePath));
			Properties pros = new Properties();
			pros.load(is);
			Enumeration enum = pros.propertyNames();
			while(enum.hasMoreElements()){
				String key = (String) enum.nextElement();
				String value = pros.get(key).toString();
				System.out.println(key+"="+value);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	//写入properties文件
	public static void writePropertiesFile(String filePath,String key,String value){
		Properties pros = new Properties();
		try {
			OutputStream os = new BufferedOutputStream(new FileOutputStream(filePath));
			pros.setProperty(key, value);
			pros.store(os, "properties_"+key);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	public static void main(String[] args){
		String filePath = "D:/dev_env/workspace/test/WebRoot/WEB-INF/classes/test.properties";
		OperationPropertiesFile.readPropertiesFile(filePath);
		System.out.println("----------------分割线-------------------");
		OperationPropertiesFile.writePropertiesFile(filePath, "driver", "oracle.jdbc.driver.OracleDriver");
		OperationPropertiesFile.readPropertiesFile(filePath);
	}
}

控制台输出结果：

url=url0
password=password0
username=username0
----------------分割线-------------------
driver=oracle.jdbc.driver.OracleDriver

再看test.properties文件内容：

#properties_driver
#Fri Nov 04 17:51:45 CST 2011
driver=oracle.jdbc.driver.OracleDriver

文件中只有新写入的driver了。