学生选课系统(连接Mysql数据库)(12页).doc
-学生选课系统(连接Mysql数据库)-第 12 页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 JFramestatic 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.parseInt(text1.getText(); s.setStudent_code(text2.getText(); try gn.correspond(s); catch (SQLException e1) / TODO Auto-generated catch blocke1.printStackTrace();主界面package immoc4.bao;import javax.swing.*;import immoc4.bao.Course;import java.awt.*;import java.awt.event.*;import java.sql.SQLException;public class Card extends JFrame * JFrame的布局管理器是BorderLayoutCourse g = new Course();GongNeng gn = new GongNeng(); JPanel p;/位于中心区域的面板 JButton b1,b2,b3,b4;/位于北部区域的四个按钮 JButton add; JButton delete; JButton update; JButton query; JLabel add_id,add_name,add_teacher_name; JLabel delete_id; JLabel update_id,update_name,update_teacher_name; JLabel query_id; JLabel query_show; JTextField text_add_id,text_add_name,text_add_teacher_name; JTextField text_delete_id; JTextField text_update_id,text_update_name,text_update_teacher_name; JTextField text_query_id; JTextArea area_query_show; CardLayout c;/设置面板p的布局 Card() super(); this.setVisible(true); this.setBounds(400,300,400,300); p = new JPanel();/实例化p c = new CardLayout();/实例化c p.setLayout(c);/设置面板p的布局为c,等价于p = new JPanel(c); /实例化4个按钮和标签 b1 = new JButton("添加课程"); b2 = new JButton("删除课程"); b3 = new JButton("修改课程"); b4 = new JButton("查询课程"); /实例化4个子面板并设定相应背景颜色 JPanel p1 = new JPanel(); JPanel p2 = new JPanel(); JPanel p3 = new JPanel(); JPanel p4 = new JPanel(); / p1.setLayout( p1.setBackground(Color.green); p2.setBackground(Color.pink); p3.setBackground(Color.orange); p4.setBackground(Color.lightGray); /把上面4个面板添加到中心面板p中，并把4个面板分别用编号为1,2,3,4代替 p.add(p1,"1"); p.add(p2,"2"); p.add(p3,"3"); p.add(p4,"4"); /实例化位于南部区域的面板，并添加4个按钮 JPanel pnorth = new JPanel(); pnorth.add(b1); pnorth.add(b2); pnorth.add(b3); pnorth.add(b4); /把p,psourth分别添加到本JFrame的中心区域和南部区域 this.add(p);/等价于this.add(p,BorderLayout.CENTER); 因为默认是把组件添加到中部 this.add(pnorth,BorderLayout.NORTH); / 添加课程 add_id = new JLabel("课程号"); text_add_id = new JTextField(30); add_name = new JLabel("课程名"); text_add_name = new JTextField(30); add_teacher_name = new JLabel("教师名"); text_add_teacher_name = new JTextField(30); add = new JButton("添加"); /为按钮b1添加监听器，当被按下时显示面板p中的前一个子面板 b1.addActionListener(new ActionListener() Override public void actionPerformed(ActionEvent e) / TODO Auto-generated method stub c.show(p,"1");/显示p中的上一个面板 p1.add(add_id); p1.add(text_add_id); p1.add(add_name); p1.add(text_add_name); p1.add(add_teacher_name); p1.add(text_add_teacher_name); p1.add(add); setVisible(true); add.addActionListener(new ActionListener()Overridepublic void actionPerformed(ActionEvent e) / TODO Auto-generated method stubg.setId(Integer.parseInt(text_add_id.getText();g.setName(text_add_name.getText();g.setTeacher_name(text_add_teacher_name.getText();try gn.addcourse(g); catch (Exception e1) / TODO Auto-generated catch blocke1.printStackTrace(); /删除课程 delete_id = new JLabel("课程号"); text_delete_id = new JTextField(20); delete = new JButton("删除"); /为按钮b2添加监听器，当被按下时显示面板p中的第2个子面板 b2.addActionListener(new ActionListener() Override public void actionPerformed(ActionEvent e) / TODO Auto-generated method stub c.show(p, "2");/显示p中代号为2的面板 p2.add(delete_id); p2.add(text_delete_id) ; p2.add(delete); setVisible(true); delete.addActionListener(new ActionListener()Overridepublic void actionPerformed(ActionEvent e) / TODO Auto-generated method stub int id = Integer.parseInt(text_delete_id.getText();try gn.delCourse(id); catch (SQLException e1) / TODO Auto-generated catch blocke1.printStackTrace(); / 修改课程 update_id = new JLabel("课程号"); text_update_id = new JTextField(30); update_name = new JLabel("课程名"); text_update_name = new JTextField(30); update_teacher_name = new JLabel("教师名"); text_update_teacher_name = new JTextField(30); update = new JButton("修改"); /以下类推 b3.addActionListener(new ActionListener() Override public void actionPerformed(ActionEvent e) / TODO Auto-generated method stub c.show(p, "3"); p3.add(update_id); p3.add(text_update_id); p3.add(update_name); p3.add(text_update_name); p3.add(update_teacher_name); p3.add(text_update_teacher_name); p3.add(update); setVisible(true); update.addActionListener(new ActionListener()Overridepublic void actionPerformed(ActionEvent e) / TODO Auto-generated method stubint id = Integer.parseInt(text_update_id.getText();g.setId(Integer.parseInt(text_update_id.getText();g.setName(text_update_name.getText();g.setTeacher_name(text_update_teacher_name.getText();try gn.updatecourse(g); catch (SQLException e1) / TODO Auto-generated catch blocke1.printStackTrace(); /查询课程 query_id = new JLabel("课程号"); text_query_id = new JTextField(20); query = new JButton("查询"); b4.addActionListener(new ActionListener() Override public void actionPerformed(ActionEvent e) / TODO Auto-generated method stub c.show(p,"4"); p4.add(query_id); p4.add(text_query_id); p4.add(query); setVisible(true); query.addActionListener(new ActionListener()Overridepublic void actionPerformed(ActionEvent e) / TODO Auto-generated method stubint id = Integer.parseInt(text_query_id.getText();try gn.get(id); catch (SQLException e1) / TODO Auto-generated catch blocke1.printStackTrace();底层增删改查功能package immoc4.bao;import ;import ;import java.sql.Connection;import ;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.util.ArrayList;import java.util.List;import ;import ;import ;public class GongNeng Cue cue = new Cue();/添加课程功能public void addcourse(Course g) throws Exception List<Course> result = new ArrayList<Course>();Connection conn = JDBC.getConnection();StringBuilder sb = new StringBuilder();sb.append("select * from student_course ");PreparedStatement ptmt = conn.prepareStatement(sb.toString();ResultSet rs = ptmt.executeQuery();/ ResultSet表示数据库结果集的数据表，通常通过执行查询数据库的语句生成，用while循环来表示结果集int x = 1;while (rs.next() if(g.getId() = rs.getInt("id") /当输入的课程号不存在的异常处理 x = 0;if(x=1)ptmt = conn.prepareStatement("insert into student_course(id,name,teacher_name) values(?,?,?)");/ SPreparedStatement是SQL语句被预编译并存储在 PreparedStatement/ 对象中。然后可以使用此对象多次高效地执行该语句ptmt.setInt(1, g.getId();ptmt.setString(2,g.getName();ptmt.setString(3, g.getTeacher_name();ptmt.execute();elsecue.denglu("对不起,你输入的课程号已存在,请重新输入");/修改课程功能public void updatecourse(Course g) throws SQLException List<Course> result = new ArrayList<Course>();Connection conn = JDBC.getConnection();StringBuilder sb = new StringBuilder();sb.append("select * from student_course ");PreparedStatement ptmt = conn.prepareStatement(sb.toString();ResultSet rs = ptmt.executeQuery();/ ResultSet表示数据库结果集的数据表，通常通过执行查询数据库的语句生成/ 用while循环来表示结果集int x = 0;while (rs.next() if(g.getId() = rs.getInt("id") /当输入的课程号不存在的异常处理 x = 1;if(x=1)ptmt = conn.prepareStatement("update student_course set name = ?,teacher_name = ? where id = ?");ptmt.setString(1, g.getName();ptmt.setString(2, g.getTeacher_name();ptmt.setInt(3, g.getId();ptmt.execute();elsecue.denglu("对不起,你输入的课程号不存在,请重新输入");/删除课程功能public void delCourse(int id) throws SQLException List<Course> result = new ArrayList<Course>();Connection conn = JDBC.getConnection();StringBuilder sb = new StringBuilder();sb.append("select * from student_course ");PreparedStatement ptmt = conn.prepareStatement(sb.toString();ResultSet rs = ptmt.executeQuery();/ ResultSet表示数据库结果集的数据表，通常通过执行查询数据库的语句生成/ 用while循环来表示结果集int x = 0;while (rs.next() if(id = rs.getInt("id") /当输入的课程号不存在的异常处理 x = 1;if(x=1) ptmt = conn.prepareStatement(" delete from student_course" + " where id=?");ptmt.setInt(1, id);ptmt.execute();elsecue.denglu("你输入的课程号不存在,请重新输入");查询课程功能public void get(Integer id) throws SQLException List<Course> result = new ArrayList<Course>();Connection conn = JDBC.getConnection();StringBuilder sb = new StringBuilder();sb.append("select * from student_course ");PreparedStatement ptmt = conn.prepareStatement(sb.toString();ResultSet rs = ptmt.executeQuery();/ ResultSet表示数据库结果集的数据表，通常通过执行查询数据库的语句生成/ 用while循环来表示结果集int x = 0;while (rs.next() if(id = rs.getInt("id") /当输入的课程号不存在的异常处理 x = 1;if(x=1)Course g = null;Connection conn1 = JDBC.getConnection();String sql = "" + " select * from student_course " + " where id=? "PreparedStatement ptmt1 = conn.prepareStatement(sql);ptmt1.setInt(1, id);ResultSet rs1 = ptmt.executeQuery();while (rs1.next() g = new Course();g.setId(rs1.getInt("id");g.setName(rs1.getString("name");g.setTeacher_name(rs1.getString("teacher_name");System.out.println("id =" + g.getId() + " ,name = " + g.getName() + ",teacher_name = " + g.getTeacher_name() + "");else cue.denglu("对不去,你输入的课程号不存在,请重新输入");/匹配登录名与密码是否符合用户 public void correspond(Student s) throws SQLException List<Student> result = new ArrayList<Student>();Connection conn = JDBC.getConnection();StringBuilder sb = new StringBuilder();sb.append("select * from student ");PreparedStatement ptmt = conn.prepareStatement(sb.toString();ResultSet rs = ptmt.executeQuery();/ ResultSet表示数据库结果集的数据表，通常通过执行查询数据库的语句生成/ 用while循环来表示结果集int x = 0;while (rs.next() if(s.getStudent_id() = rs.getInt("student_id")&&s.getStudent_code().equals(rs.getString("student_code") x = 1;break;if(s.getStudent_id() = rs.getInt("student_id")if(s.getStudent_code().equals(rs.getString("student_code")=false)x = 3; break;if(s.getStudent_id() != rs.getInt("student_id")x = 2;if(x = 1) Card cd = new Card();if(x = 2)cue.denglu("用户不存在,请重新输入");if(x = 3)cue.denglu("您输入的密码有误,请重新输入");定义课程类package immoc4.bao;public class Course private int id;private String name;private String teacher_name;public int getId() return id;public void setId(int id) this.id = id;public String getName() return name;public void setName(String name) this.name = name;public String getTeacher_name() return teacher_name;public void setTeacher_name(String teacher_name) this.teacher_name = teacher_name;public String toString() return "Course(id =" + id + ",name = " + name + ",teacher_name = " + teacher_name + ")"定义学生类package immoc4.bao;public class Student private int student_id;private String student_name;private String student_code;public int getStudent_id() return student_id;public void setStudent_id(int student_id) this.student_id = student_id;public String getStudent_name() return student_name;public void setStudent_name(String student_name) this.student_name = student_name;public String getStudent_code() return student_code;public void setStudent_code(String student_code) this.student_code = student_code;public String toString() return "Student(id =" + student_id + ",name = " + student_name + ",code = " + student_code + ")"将错误提示单独写成一个界面package immoc4.bao;
