public class LoadPropTest {

    public static void main(String[] args) throws IOException {

        //一、Properties的load方法加载文件输入流

        Properties props=new Properties();

        File file1=new File("F:/Program Files/Java/IdeaProjects/MyBatisDemo/src/db.properties");

        File file2=new File("src/db.properties");

        File file3=new File("src/com/biguo/datasource/jdbc.properties");

        //File file4=new File("jdbc.properties"); 报错，引起了我对相对路径的思考

        FileInputStream fileInputStream1=new FileInputStream(file3);

        FileInputStream fileInputStream2=new FileInputStream("src/com/biguo/datasource/jdbc.properties");

        props.load(fileInputStream2);

        System.out.println(props.getProperty("url"));

        //二、通过类加载器 加载配置文件

        Properties p = new Properties();

        InputStream in = LoadPropTest.class.getClassLoader().getResourceAsStream("com/biguo/datasource/jdbc.properties");

        p.load(in);

        String name = p.getProperty("username");

        System.out.println(name);

        //三、基名，文件必须是key=value的properties文件

        ResourceBundle bundle = ResourceBundle.getBundle("com/biguo/datasource/jdbc");

        String driver = bundle.getString("username");

        System.out.println(driver);

    }

}

<properties resource="com/biguo/datasource/jdbc.properties">

        <!-- 其中的属性就可以在整个配置文件中被用来替换需要动态配置的属性值。 -->

        <!--<property name="password" value="pigu20ing" />-->

</properties>