学生选课系统(连接Mysql数据库).doc

/*
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.parseInt(text1.getText()));
s.setStudent_code(text2.getText());
try {

gn.correspond(s);
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.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BorderLayout
*/
Course 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(){

@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub

g.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 block
e1.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(){

@Override
public 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 block
e1.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()
{
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
int 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 block
e1.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(){

@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
int id = Integer.parseInt(text_query_id.getText());
try {
gn.get(id);
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
});

/*
底层增删改查功能
*/
package immoc4.bao;

import java.awt.FlowLayout;
import java.io.ByteArrayInputStream;
import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import javax.swing.JLabel;
import javax.swing.JTextField;

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();
}else{
cue.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();
}else{
cue.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();
}else{
cue.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