jdbc连接Msql 数据

   private static final String CLASS = "com.mysql.jdbc.Driver";  //驱动类       private static final String DRIVER = "jdbc:mysql://localhost:3306/SHIOT"; //驱动       private static final String USERNAME = "root"; //数据库用户名       private static final String PWD = "root";  //数据库密码              private static Connection conn = null;       private static PreparedStatement  stmt=null;    private static ResultSet rs = null;    public  Connection getCon() {        try {   Class.forName(CLASS);   conn = DriverManager.getConnection(DRIVER,USERNAME,PWD);  } catch (ClassNotFoundException e) {   e.printStackTrace();  }   catch (SQLException e) {   e.printStackTrace();  }           return conn;  

 }