学生选课系统(连接Mysql数据库)

/* JDBC 连接数据库 */ package immoc4.bao; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class JDBC { private static final String URL = "jdbc:mysql://localhost:3306/a?characterEncoding=utf8"; private static final String USER = "root"; private static final String PASSWORD = "995923"; private static Connection conn = null; static { try { Class.forName("com.mysql.jdbc.Driver"); conn = DriverManager.getConnection(URL, USER, PASSWORD); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } } public static Connection getConnection() { return conn; } } /* 登录界面 */ package immoc4.bao; import java.awt.FlowLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.sql.SQLException; import java.util.Scanner; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JTextField; public class View extends JFrame{ static GongNeng gn = new GongNeng(); static Student s = new Student(); static JTextField text1; static JTextField text2; static JButton button; public void denglu(){ setLayout(new FlowLayout()); add(new JLabel("用户id:")); text1 = new JTextField(20); add(text1); add(new JLabel("密码:")); text2 = new JTextField(20); add(text2); button = new JButton("登录"); add(button); setVisible(true); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //关闭窗口 } public static void main(String []args){ View dl = new View(); dl.setBounds(300, 300, 300, 200); dl.setTitle("学生选课管理系统"); dl.denglu(); button.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { // TODO Auto-generated method stub dl.dispose(); s.setStudent_id(Integer.pars...