大学JAVA实验六 学生选课管理系统

学生选课管理系统

实验内容：
1、为选修课程的学生设计“学生选课数据库管理系统”，能进行相关记录的插入、修改、删除和查询等操作。
2、在实现前面功能的基础上，将操作界面改为图形用户界面。

前期工作：

--在企业管理器中新建一数据库stumanage，
--再创建一用户xiaohuan,步骤如下：

--1、企业管理器-->安全性-->登录-->新建登录-->

--名称输入xiaohuan
--身份验证为SQL Server身份验证-->输入密码mintji
--默认设置中数据库选stumanage

--2、转到数据库访问
--勾选stumanage，确定退出即可

--3、用登录名xiaohuan,密码mintji打开查询分析器，检查当前数据库是否是stumanage，不是就选用

stumanage即可
--创建表xuan和login

create table xuanke(
studid varchar(12) not null,
name char(8) not null,
class char(20),
sex char(2),
subject varchar(30),
telphone char(20),
teacher char(10)
);

create table login(
admin char(10),
password char(20)
);

insert into login values(
'mintji', 'mintji123'
);

--4、将SQL Server 2000的JDBC3个驱动包拷贝到java的jre类库的扩展包里，
--如我的为C:/Program Files/Java/jdk6.016/jre/lib/ext

--正确运行的话会有一要求登录的对话框，登录帐号为mintji,密码为mintji

--如果连接数据库失败，请检查:

1、SQL Server 2000是否已启动

2、检查SQL Server 2000是否已安装SQL Server 2000SP4补丁包（必需）

3、环境变量是否正确设置，参考给出环境变量重新配置：

配置环境在我的电脑右键属性，高级，环境变量，新建以下系统变量。

假设我们的jdk安装在C:/Program Files/Java/jdk6.016

1 变量名：JAVA_HOME
变量值：C:/Program Files/Java/jdk6.016

(说明:变量值就是JDK的安装路径，也就是你电脑上的JDK在哪)

2 变量名：CLASSPATH
变量值：.;%JAVA_HOME%/lib/dt.jar;%JAVA_HOME%/lib/tools.jar

3 变量名：path
变量值：%JAVA_HOME%/bin

(说明：第2个和第3个变量只需 把变量名和变量值 直接复制到 变量名和变量值上就可以了！不用改！

)

1、为选修课程的学生设计“学生选课数据库管理系统”，能进行相关记录的插入、修改、删除和查询等操作。

DBOperation.java

package first;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class DBOperation {

String url = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=stumanage";
String user = "xiaohuan";
String password = "mintji";

Connection conn;
Statement stmt;
ResultSet rs;

public DBOperation() {
conn = null;
stmt = null;
rs = null;

try {
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
} catch (ClassNotFoundException e) {
System.out.println("未能找到SQLServerDriver，请检查是否已加载SQLServer驱动！");

e.printStackTrace();
}

try {
conn = DriverManager.getConnection(url, user, password);
stmt = conn.createStatement();
} catch (SQLException e) {
System.out.println("连接数据库失败！");

e.printStackTrace();
}
}

public ResultSet chaxun(String sql) {// 查询

try {
rs = stmt.executeQuery(sql);// SELECT
} catch (SQLException e) {
System.out.println("执行" + sql + "语句失败！");
e.printStackTrace();
}

return rs;
}

public void tianshangai(String sql) {// 添，删，查都调用这个方法
try {
stmt.executeUpdate(sql);// INSERT,UPDATE,DELETE
} catch (SQLException e) {
System.out.println("执行" + sql + "语句失败！");
e.printStackTrace();
}
}

public void closeAll() {
try {
rs.close();
} catch (SQLException e) {
// e.printStackTrace();
} finally {
if (rs != null) {
rs = null;
}
}
try {
stmt.close();
} catch (SQLException e) {
// e.printStackTrace();
} finally {
if (stmt != null) {
stmt = null;
}
}
try {
conn.close();
} catch (SQLException e) {
// e.printStackTrace();
} finally {
if (conn != null) {
conn = null;
}
}
}
}

Operation.java

package first;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.InputMismatchException;
import java.util.Scanner;

public class Operation {
DBOperation DBO = new DBOperation();
String sql;

Scanner _order = new Scanner(System.in);
int order;

static boolean exit = false;

public void showTips() {

System.out
.print("/t*****************************************************************/n");
System.out.print("/t/t/t#/t 1---添加学生选课信息/t #/n");
System.out.print("/t/t/t#/t 2---修改学生选课信息/t #/n");
System.out.print("/t/t/t#/t 3---删除学生选课信息/t #/n");
System.out.print("/t/t/t#/t 4---查看学生选课信息/t #/n");
System.out.print("/t/t/t#/t 0---退出程序/t/t #/n");
System.out
.print("/t*****************************************************************/n");
System.out.print("请选择你的操作：");
order = _order.nextInt();

switch (order) {
case 1:
System.out.print("/t/t/t#/t 添加学生选课信息/t #/n");
insert();
break;
case 2:
System.out.print("/t/t/t#/t 修改学生选课信息/t #/n");

break;
case 3:
System.out.print("/t/t/t#/t 删除学生选课信息/t #/n");
delete();
break;
case 4:
System.out.print("/t/t/t#/t 查看学生选课信息/t #/n");
select();
break;
case 0:
exit = true;
System.out.println("/n/n/n/t/t/t# /t成功退出程序！/t/t #/n");
break;
default:
System.out
.println("/t/t提示：" + order + "不是本系统的操作代号，请确认后重新来过！/n/n/n");
}
}

public void insert() {// 添加记录
sql = null;

System.out.print("请输入学号：");
String studid = _order.next();
System.out.print("请输入姓名：");
String name = _order.next();
System.out.print("请输入班级：");
String _class = _order.next();
System.out.print("请输入性别：");
String sex = _order.next();
System.out.print("请输入所选课程：");
String subject = _order.next();
System.out.print("请输入电话：");
String telphone = _order.next();
System.out.print("请输入本课程的教师姓名：");
String teacher = _order.next();

sql = "insert into xuanke(studid,name,class,sex,subject,telphone,teacher) values('"
+ studid
+ "','"
+ name
+ "','"
+ _class
+ "','"
+ sex
+ "','"
+ subject
+ "','"
+ telphone
+ "','"
+ teacher
+ "')";

if (sql != null && sql != "") {
DBO.tianshangai(sql);
}
}

public void delete() {
sql = null;

System.out
.print("/t*****************************************************************/n");
System.out.print("/t/t/t#/t 1---按学生编号删除/t #/n");
System.out.print("/t/t/t#/t 2---按学生姓名删除/t #/n");
System.out.print("/t/t/t#/t 0---退出程序/t/t #/n");
System.out
.print("/t*****************************************************************/n");
System.out.print("请选择你的操作：");

order = _order.nextInt();
switch (order) {
case 1:
System.out.print("请输入要删除的学生的编号：");
String id = _order.next();
sql = "delete from xuanke where studid=" + id;
break;
case 2:
System.out.print("请输入要删除的学生的姓名：");
String name = _order.next();
sql = "delete from xuanke where name=" + name;
break;
case 0:
exit = true;
System.out.println("/n/n/n/t/t/t# /t成功退出程序！/t/t #/n");
break;
default:
System.out
.println("/t/t提示：" + order + "不是本系统的操作代号，请确认后重新来过！/n/n/n");
}

if (sql != null && sql != "") {
DBO.tianshangai(sql);
}
}

public void update() {
sql = null;

System.out.print("请输入要删除的学生的编号：");
String id = _order.next();
sql = "delete from xuanke where studid=" + id;

if (sql != null && sql != "") {
DBO.tianshangai(sql);
}
}

public void select() {// 查询记录
sql = null;

System.out
.print("/t*****************************************************************/n");
System.out.print("/t/t/t#/t 1---按学生编号查询/t #/n");
System.out.print("/t/t/t#/t 2---按学生姓名查询/t #/n");
System.out.print("/t/t/t#/t 3---查看所有选课信息/t #/n");
System.out.print("/t/t/t#/t 0---退出程序/t/t #/n");
System.out
.print("/t*****************************************************************/n");
System.out.print("请选择你的操作：");

order = _order.nextInt();
switch (order) {
case 1:
System.out.print("请输入要查询的学生的编号：");
String id = _order.next();
sql = "select * from xuanke where studid=" + id;
break;
case 2:
System.out.print("请输入要查询的学生的姓名：");
String name = _order.next();
sql = "select * from xuanke where name='" + name + "'";
break;
case 3:
sql = "select * from xuanke";
break;
case 0:
exit = true;
System.out.println("/n/n/n/t/t/t# /t成功退出程序！/t/t #/n");
break;
default:
System.out
.println("/t/t提示：" + order + "不是本系统的操作代号，请确认后重新来过！/n/n/n");
}

ResultSet rs = DBO.chaxun(sql);

try {
while (rs.next()) {
// System.out.println("学生编号：/n姓名：/n班级：/n性别：/n年龄：/n电话：/n教师：");
System.out.println(rs.getString(1) + "/t" + rs.getString(2)
+ "/t" + rs.getString(3) + "/t/t" + rs.getString(4)
+ "/t" + rs.getString(5) + "/t/t/t" + rs.getString(6)
+ "/t" + rs.getString(7));
}
} catch (SQLException e) {
e.printStackTrace();
}
}

public static void main(String agus[]) {
Operation ope = new Operation();
while (!exit) {
try {
ope.showTips();
} catch (InputMismatchException ime) {
System.out.print("/t/t/t#/t 非法操作，请确认后重新来过！/t #/n/n/n/n");
}
}
}
}

2、在实现前面功能的基础上，将操作界面改为图形用户界面。

Mintji.java

package second;

import first.DBOperation;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.HeadlessException;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Vector;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JRootPane;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.table.DefaultTableModel;

public class Mintji extends JFrame {
String sql;
ResultSet rs;

DBOperation dbo;
JFrame update;
JFrame insert;
ImageIcon icon;
JFrame chakan;

String id;
String name;
String _class;
String sex;
String subject;
String tel;
String teacher;

JLabel j1 = new JLabel("学号：");
JLabel j2 = new JLabel("姓名：");
JLabel j3 = new JLabel("班级：");
JLabel j4 = new JLabel("性别：");
JLabel j5 = new JLabel("选修科目：");
JLabel j6 = new JLabel("电话：");
JLabel j7 = new JLabel("任课教师：");

JTextField t1;
JTextField t2;
JTextField t3;
JTextField t4;
JTextField t5;
JTextField t6;
JTextField t7;

JButton inbut;
JButton quxiao;

JScrollPane scrollPane;

MenuListener listener = new MenuListener(this);

public Mintji(DBOperation dbo) throws HeadlessException {
// super();
this.dbo = dbo;
}

private static final long serialVersionUID = 1L;

JButton[] button = new JButton[5];
JTable table;

Vector<Vector<String>> row;// 数据库空的每一行,因为加入的也为Vector，所以要用Vector<Vector<String>>

public Mintji() {
rs = null;
sql = null;
dbo = new DBOperation();

super.setTitle("学生选课管理系统");
icon = new ImageIcon("195032.jpg");
super.setIconImage(icon.getImage());
scrollPane = new JScrollPane();// 这几行代码没有正常工作，但又是必须，因为如果用户以进入系统就添加信息，需要mintji.remove(mintji.scrollPane);
JLabel wel = new JLabel("欢迎使用学生选课管理系统");
wel.setBounds(200, 200, 50, 10);
scrollPane.add(wel);
super.add(scrollPane, "Center");

JPanel left = new JPanel();
left.setBackground(new Color(123, 123, 123));
left.setLayout(new GridLayout(15, 1, 2, 2));
left.add(new JLabel());
left.add(new JLabel("学生选课管理系统"));
left.add(new JLabel());

String buttonName[] = { "添加记录", "删除记录", "查找记录", "修改记录", "退出系统" };

for (int i = 0; i < buttonName.length; i++) {
button[i] = new JButton(buttonName[i]);
button[i].setFocusPainted(false);// 去掉点击时的虚线框
// button[i].setBorderPainted(false);//去掉外边框
button[i].addActionListener(listener);
left.add(button[i]);
}

super.add(left, "West");

super.setDefaultCloseOperation(EXIT_ON_CLOSE);
super.setSize(800, 500);
super.setLocation(150, 150);
super.setResizable(false);
super.setVisible(true);
}

public void getDataFromDB() {// 从数据库中读取数据
// sql = "select * from xuanke";// 测试
row = new Vector<Vector<String>>();
ResultSet rs = dbo.chaxun("select * from xuanke order by subject");// 按选修的科目排序
try {
while (rs.next()) {
Vector<String> col = new Vector<String>();
col.add((rs.getString(1)).trim());
col.add((rs.getString(2)).trim());
col.add((rs.getString(3)).trim());
col.add((rs.getString(4)).trim());
col.add((rs.getString(5)).trim());
col.add((rs.getString(6)).trim());
col.add((rs.getString(7)).trim());
this.row.add(col);
}
} catch (SQLException e) {
e.printStackTrace();
}
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}

public void showTable() {
getDataFromDB();// 获取数据库空的数据放到表中

String[] tableTitles = { "学号", "姓名", "班级", "性别", "选修科目", "电话", "任课教师" };// 标题

Vector<String> tableTitle = new Vector<String>();// 蒋列标题放到迭代器中，DefaultTableModel要用
for (int i = 0; i < tableTitles.length; i++) {
tableTitle.add(tableTitles[i]);
}

DefaultTableModel dtm = new DefaultTableModel();
dtm.setDataVector(row, tableTitle);
table = new JTable(dtm);// 新建表
table.setRowHeight(20);

table.setPreferredScrollableViewportSize(new Dimension(550, 30));
scrollPane = new JScrollPane(table);// JScrollPane会自动取得列标题

super.getContentPane().add(scrollPane, BorderLayout.CENTER);// 将表放在窗口的中央
}

public void showInsert() {

insert = new JFrame("添加选课信息");
insert.setUndecorated(true); // 去掉窗口的装饰
insert.getRootPane().setWindowDecorationStyle(
JRootPane.COLOR_CHOOSER_DIALOG);// 采用指定的窗口装饰风格
JPanel in = new JPanel();
in.setLayout(new GridLayout(8, 2, 2, 2));

t1 = new JTextField();
t2 = new JTextField();
t3 = new JTextField();
t4 = new JTextField();
t5 = new JTextField();
t6 = new JTextField();
t7 = new JTextField();

in.add(j1);
in.add(t1);
in.add(j2);
in.add(t2);
in.add(j3);
in.add(t3);
in.add(j4);
in.add(t4);
in.add(j5);
in.add(t5);
in.add(j6);
in.add(t6);
in.add(j7);
in.add(t7);

inbut = new JButton("添加");
inbut.addActionListener(listener);
quxiao = new JButton("取消");
quxiao.addActionListener(listener);

in.add(quxiao);
in.add(inbut);

insert.add(in);

insert.setLocation(350, 300);
insert.setSize(300, 250);
insert.setResizable(false);
insert.setVisible(true);
}

public void insert() {

id = (t1.getText()).trim();
name = (t2.getText()).trim();
_class = (t3.getText()).trim();
sex = (t4.getText()).trim();
subject = (t5.getText()).trim();
tel = (t6.getText()).trim();
teacher = (t7.getText()).trim();

sql = "insert into xuanke(studid,name,class,sex,subject,telphone,teacher) values('"
+ id
+ "','"
+ name
+ "','"
+ _class
+ "','"
+ sex
+ "','"
+ subject + "','" + tel + "','" + teacher + "')";

dbo.tianshangai(sql);

insert.setVisible(false);

JOptionPane.showMessageDialog(null, "成功添加学号为" + id + "的选课信息！", "系统提示",
JOptionPane.INFORMATION_MESSAGE);
}

public void showDelete() {
String stud_id = (javax.swing.JOptionPane.showInputDialog("请输入要删除的学号："))
.trim();
if (stud_id == null || stud_id.equals("")) {// 不接受散客聊天
JOptionPane.showMessageDialog(null, "学号不能为空哦，请输入要删除的学号！", "系统提示",
JOptionPane.ERROR_MESSAGE);
stud_id = (javax.swing.JOptionPane.showInputDialog("请输入要删除的学号："))
.trim();
}
//sql = "delete from xuanke where studid='" + stud_id + "'";
dbo.tianshangai("delete from xuanke where studid='" + stud_id + "'");
JOptionPane.showMessageDialog(null, "成功删除学号为" + stud_id + "的选课信息！",
"系统提示", JOptionPane.INFORMATION_MESSAGE);

}

public void chakan() {
String stud_id = (javax.swing.JOptionPane.showInputDialog("请输入要查找的学号："))
.trim();
if (stud_id == null || stud_id.equals("")) {// 查询的学号不能为空
JOptionPane.showMessageDialog(null, "学号不能为空哦，请输入要查找的学号！", "系统提示",
JOptionPane.ERROR_MESSAGE);
stud_id = (javax.swing.JOptionPane.showInputDialog("请输入要查找的学号："))
.trim();
}

chakan = new JFrame("查看选课信息");
chakan.setUndecorated(true); // 去掉窗口的装饰
chakan.getRootPane().setWindowDecorationStyle(
JRootPane.COLOR_CHOOSER_DIALOG);// 采用指定的窗口装饰风格

JPanel ck = new JPanel();
ck.setLayout(new GridLayout(8, 2, 2, 2));

if (stud_id == null || stud_id == "") {// 如果 学号为空，就什么都不做

} else {
ResultSet rs = dbo.chaxun("select * from xuanke where studid='"
+ stud_id + "'");

try {
if (rs.next()) {
id = (rs.getString(1)).trim();
name = (rs.getString(2)).trim();
_class = (rs.getString(3)).trim();
sex = (rs.getString(4)).trim();
subject = (rs.getString(5)).trim();
tel = (rs.getString(6)).trim();
teacher = (rs.getString(7)).trim();
}
} catch (SQLException e) {
e.printStackTrace();
}

t1 = new JTextField(id);
t2 = new JTextField(name);
t3 = new JTextField(_class);
t4 = new JTextField(sex);
t5 = new JTextField(subject);
t6 = new JTextField(tel);
t7 = new JTextField(teacher);

ck.add(j1);
ck.add(t1);
ck.add(j2);
ck.add(t2);
ck.add(j3);
ck.add(t3);
ck.add(j4);
ck.add(t4);
ck.add(j5);
ck.add(t5);
ck.add(j6);
ck.add(t6);
ck.add(j7);
ck.add(t7);

inbut = new JButton("确定");
inbut.addActionListener(listener);
quxiao = new JButton("取消");
quxiao.addActionListener(listener);

ck.add(quxiao);
ck.add(inbut);

chakan.add(ck);

chakan.setLocation(350, 300);
chakan.setSize(300, 250);
chakan.setResizable(false);
chakan.setVisible(true);
}
}

public void showUpdate() {
String stud_id = (javax.swing.JOptionPane.showInputDialog("请输入要修改的学号："))
.trim();
if (stud_id == null || stud_id.equals("")) {// 查询的学号不能为空
JOptionPane.showMessageDialog(null, "学号不能为空哦，请输入要修改的学号！", "系统提示",
JOptionPane.ERROR_MESSAGE);
stud_id = (javax.swing.JOptionPane.showInputDialog("请输入要修改的学号："))
.trim();
}

update = new JFrame("修改选课信息");
update.setUndecorated(true);
update.getRootPane().setWindowDecorationStyle(
JRootPane.COLOR_CHOOSER_DIALOG);

JPanel up = new JPanel();
up.setLayout(new GridLayout(8, 2, 2, 2));

ResultSet rs = dbo.chaxun("select * from xuanke where studid='"
+ stud_id + "'");

try {
if (rs.next()) {
id = (rs.getString(1)).trim();
name = (rs.getString(2)).trim();
_class = (rs.getString(3)).trim();
sex = (rs.getString(4)).trim();
subject = (rs.getString(5)).trim();
tel = (rs.getString(6)).trim();
teacher = (rs.getString(7)).trim();
}
} catch (SQLException e) {
e.printStackTrace();
}

t1 = new JTextField(id);
t2 = new JTextField(name);
t3 = new JTextField(_class);
t4 = new JTextField(sex);
t5 = new JTextField(subject);
t6 = new JTextField(tel);
t7 = new JTextField(teacher);

up.add(j1);
up.add(t1);
up.add(j2);
up.add(t2);
up.add(j3);
up.add(t3);
up.add(j4);
up.add(t4);
up.add(j5);
up.add(t5);
up.add(j6);
up.add(t6);
up.add(j7);
up.add(t7);

inbut = new JButton("修改");
inbut.addActionListener(listener);
quxiao = new JButton("取消");
quxiao.addActionListener(listener);

up.add(quxiao);
up.add(inbut);

update.add(up);

update.setLocation(350, 300);
update.setSize(300, 250);
update.setResizable(false);
update.setVisible(true);
}

public void update() {

id = (t1.getText()).trim();
name = (t2.getText()).trim();
_class = (t3.getText()).trim();
sex = (t4.getText()).trim();
subject = (t5.getText()).trim();
tel = (t6.getText()).trim();
teacher = (t7.getText()).trim();

sql = "delete from xuanke where studid='" + id + "'";
dbo.tianshangai(sql);
sql = "insert into xuanke(studid,name,class,sex,subject,telphone,teacher) values('"
+ id
+ "','"
+ name
+ "','"
+ _class
+ "','"
+ sex
+ "','"
+ subject + "','" + tel + "','" + teacher + "')";

dbo.tianshangai(sql);
update.setVisible(false);
JOptionPane.showMessageDialog(null, "成功修改学号为" + id + "的选课信息！", "系统提示",
JOptionPane.INFORMATION_MESSAGE);
}

public void loogin() {
String user = (javax.swing.JOptionPane.showInputDialog("请输入登录帐号："))
.trim();
if (user == null || user.equals("")) {// 查询的学号不能为空
JOptionPane.showMessageDialog(null, "登录帐号不能为空哦，请输入登录帐号！", "系统提示",
JOptionPane.ERROR_MESSAGE);
user = (javax.swing.JOptionPane.showInputDialog("请输入登录帐号：")).trim();
}
String password = (javax.swing.JOptionPane.showInputDialog("请输入登录密码："))
.trim();
if (password == null || password.equals("")) {// 查询的学号不能为空
JOptionPane.showMessageDialog(null, "登录密码不能为空哦，请输入登录密码！", "系统提示",
JOptionPane.ERROR_MESSAGE);
password = (javax.swing.JOptionPane.showInputDialog("请输入登录密码："))
.trim();
}

rs = dbo.chaxun("select * from login where admin='" + user
+ "' and password='" + password + "'");
try {
if (!rs.next()) {
// return true;
JOptionPane.showMessageDialog(null, "您输入的帐号或密码有误，请重新登录！",
"系统提示", JOptionPane.ERROR_MESSAGE);
loogin();
}
} catch (SQLException e) {
e.printStackTrace();
}

JOptionPane.showMessageDialog(null, "欢迎使用学生选课信息管理系统！", "系统提示：登录成功",
JOptionPane.INFORMATION_MESSAGE);
}

public static void main(String[] args) {
Mintji mintji = new Mintji();
mintji.loogin();
// mintji.showTable();
}
}

MenuListener.java

package second;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class MenuListener implements ActionListener {

public MenuListener(Mintji mintji) {
// super();
this.mintji = mintji;
}

Mintji mintji;
String command;

@Override
public void actionPerformed(ActionEvent ae) {
command = ae.getActionCommand();

if (command.equals("添加记录")) {
mintji.showInsert();
} else if (command.equals("添加")) {
mintji.insert();
mintji.remove(mintji.scrollPane);
mintji.showTable();
mintji.validate();
} else if (command.equals("删除记录")) {
mintji.showDelete();
mintji.remove(mintji.scrollPane);
mintji.showTable();
mintji.validate();
} else if (command.equals("查找记录")) {
mintji.showTable();
mintji.validate();
mintji.chakan();
} else if (command.equals("确定")) {
mintji.chakan.setVisible(false);
}else if (command.equals("修改记录")) {
mintji.showUpdate();
}else if(command.equals("修改")){
mintji.update();
mintji.remove(mintji.scrollPane);
mintji.showTable();
mintji.validate();
} else if (command.equals("退出系统")) {
System.exit(0);
}

}

}