读取配置文件javase

1.通过字节码文件的类加载器的字节流读取文件。
@Test
     public void f1() throws Exception{
        //通过字节流文件获取jdbc连接
         InputStream is = Demo1.class.getClassLoader().getResourceAsStream("jdbc.properties");
         Properties pr = new Properties();
         pr.load(is);
　　　　　//通过键获取值
         String driverClass = pr.getProperty("driverClass");
         String url = pr.getProperty("url");
         String user = pr.getProperty("user");
         String password=pr.getProperty("password");
        
         Class.forName(driverClass);
        
         Connection conn = DriverManager.getConnection(url, user, password);
         is.close();
         System.out.println(conn);
            
     }

2.通过字符输入流读取配置文件，文件的路径为绝对路径。

@Test
    public void f2() throws Exception{
        //通过字符流文件获取jdbc连接
        FileReader fr = new FileReader("../propeities/src/jdbc.properties");
        Properties pr = new Properties();
        pr.load(fr);
        String driverClass = pr.getProperty("driverClass");
        String url = pr.getProperty("url");
        String user = pr.getProperty("user");
        String password=pr.getProperty("password");
        
         Class.forName(driverClass);
            
         Connection conn = DriverManager.getConnection(url, user, password);
        fr.close();
         System.out.println(conn);
    }

3.通过ResourceBundle里的静态方法getBundle。

@Test
    public void f3() throws Exception{
        //
        ResourceBundle rb = ResourceBundle.getBundle("jdbc");
        String driverClass = rb.getString("driverClass");
        String url = rb.getString("url");
        String user = rb.getString("user");
        String password = rb.getString("password");
        Class.forName(driverClass);
        
        Connection conn = DriverManager.getConnection(url, user, password);
         System.out.println(conn);
    }

配置文件如下：

driverClass=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/store28 //store28为自己的数据库名字  localhost:3306/ 可以直接替换为/
user=root
password=123