//1.驱动	
Class.forName("com.mysql.jdbc.Driver");
//2.连接	
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/hm", "root", "admin");
//st载体	
Statement st = conn.createStatement();
//sql语句	
String sql = "select * from test";
//执行并接受返回	
ResultSet result = st.executeQuery(sql);