类的反射及xml文件的解析

类的反射

xml文件的解析

.properties||.xml配置文件的创建及读取内容

//创建对象
        Properties properties = new Properties();
        //存储
        properties.setProperty("driver", "com.mysql.jdbc.Driver");
        properties.setProperty("url", "jdbc:mysql://localhost:3306/userdb");
        properties.setProperty("user", "root");
        properties.setProperty("password", "");

        //存储到绝对路径盘符
        properties.store(new FileOutputStream(new File("e://home/soldier/SOLDIER/idea_project/Order/jdbc.properties")), "db配置");
        properties.storeToXML(new FileOutputStream(new File("e://home/soldier/SOLDIER/idea_project/Order/c3p0.xml")), "数据库连接池");
        //使用相对路径-->当前工程
        properties.store(new FileOutputStream(new File("jdbc.properties")), "db配置");
        properties.storeToXML(new FileOutputStream(new File("c3p0.xml")), "数据库连接池");
        //使用相对路径-->当前工程下的xxx
        properties.store(new FileOutputStream(new File("src/com/soldier/db/jdbc.properties")), "db配置");

        //读取绝对路径
        properties.load(new FileReader("e://home/soldier/SOLDIER/idea_project/Order/jdbc.properties"));
        //使用相对路径-->当前工程
        properties.load(new FileReader("jdbc.properties"));
        //使用相对路径-->当前工程下的xxx
        properties.load(new FileReader(new File("src/com/soldier/db/jdbc.properties")));

        //如果没有就输出后面的默认值
        System.out.println(properties.getProperty("user", "null"));