//加载文件
public static void testLoadProperties() throws Exception {

    Properties properties = new Properties();

    InputStream in = new FileInputStream("E:/itcast/config.properties");

    properties.load(in); // 加载

    in.close();

    System.out.println(properties);

}

//写配置文件

public static void testStoreProperties() throws Exception {

    // 准备配置信息

    Properties properties = new Properties();

    properties.setProperty("name", "李四");

    properties.setProperty("age", "20");

    // 准备

    OutputStream out = new FileOutputStream("d:/my.properties");

    String comments = "这是我的配置文件";

    // 写出去

    properties.store(out, comments);

    out.close();

}

static Properties properties ;

    static{

        try {

            properties = new Properties();

            Class clazz = dd.class;

            InputStream inputStream = clazz.getResourceAsStream("/my.properties"); //  "/"������Classpath��·����           getResourceAsStream �÷�������ʹ�õ�·������ʹ�������ļ�·����

            properties.load(inputStream);

        } catch (IOException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

    }

    public static void main(String[] args) {

        System.out.println("��ǰ·����"+ new File(".").getAbsolutePath() );

        System.out.println( properties.getProperty("userName")+":"+properties.getProperty("password"));

    }

/**

         * 1. getRealPath读取,返回资源文件的绝对路径

         */

        /*String path = this.getServletContext().getRealPath("/WEB-INF/classes/db.properties");

        System.out.println(path);

        File file = new File(path);

        FileInputStream in = new FileInputStream(file);*/

        /**

         * 2. getResourceAsStream() 得到资源文件，返回的是输入流

         */

        InputStream in = this.getServletContext().getResourceAsStream("/WEB-INF/classes/db.properties");

        Properties prop = new Properties();

        //读取资源文件

        prop.load(in);

        String user = prop.getProperty("user");

        String password = prop.getProperty("password");

        System.out.println("user="+user);

        System.out.println("password="+password);

    }