Exception in thread "main" java.lang.NullPointerException
at net.fqq.student.gui.MainFrame.initGUI(MainFrame.java:269)
at net.fqq.student.gui.MainFrame.<init>(MainFrame.java:114)
at net.fqq.student.gui.MainFrame.main(MainFrame.java:543)
package net.fqq.student.gui;
import net.fqq.student.app.Application;
import net.fqq.student.bean.Status;
import net.fqq.student.service.StatusService;
import net.fqq.student.service.impl.StatusServiceImpl;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.IOException;
public class MainFrame extends JFrame{
/*
菜单部分
*/
private JMenuBar mnbMain;
/*
设置菜单
*/
private JMenu mnuSet;
private JMenuItem mniSetCollegeInfo;
private JMenuItem mniSetStatusBar;
private JMenuItem mniChangePassword;
private JMenuItem mniExit;
/*
操作菜单
*/
private JMenu mnuOperate;
private JMenuItem mniAddStudent;
private JMenuItem mniBrowseStudent;
private JMenuItem mniEditStudent;
/*
删除菜单
*/
private JMenu mnuDelStu;
private JMenuItem mniDelStudentById;
private JMenuItem mniDelStudentsByClass;
private JMenuItem mniDelStudentsByDepartment;
/*
查询菜单
*/
private JMenu mnuFind;
private JMenuItem mniFindStudentById;
private JMenuItem mniFindStudentsByName;
private JMenuItem mniFindStudentsByClass;
private JMenuItem mniFindStudentsByDepartment;
/*
统计菜单
*/
private JMenu mnuCount;
private JMenuItem mniCountStudentsBySex;
private JMenuItem mniCountStudentsByClass;
private JMenuItem mniCountStudentsByDepartment;
/*
帮助菜单
*/
private JMenu mnuHelp;
private JMenuItem mniHelp;
private JMenuItem mniAbout;
/*
面板
*/
private JPanel panel;
private JPanel pnlCenter;
private JPanel pnlSouth;
/*
状态栏标签
*/
private JLabel lblStatusBar;
/*
背景标签
*/
private JLabel lblBackground;
/**
图标对象
*/
private ImageIcon imgCollege;
private ImageIcon imgExit;
private ImageIcon imgPassword;
private ImageIcon imgQuery;
private ImageIcon imgBrowse;
private ImageIcon imgCount;
private ImageIcon imgBackground;
/*
工具栏
*/
private JToolBar toolbar;
/*
按钮
*/
private JButton btnSetCollege;
private JButton btnChangePassword;
private JButton btnFindStudentById;
private JButton btnExit;
private JButton btnBrowseStudent;
private JButton btnCountByDepartment;
/*
状态对象
*/
private Status status;
/*
状态服务对象
*/
private StatusService statusService;
/**
构造方法
@param title
*/
public MainFrame(String title) {
super(title);
initGUI();
}
/**
初始化图形用户界面
*/
private void initGUI() {
// 创建主菜单
mnbMain = new JMenuBar();
// 创建【设置】菜单及其菜单项
mnuSet = new JMenu("系统设置[S]");
mnuSet.setMnemonic(KeyEvent.VK_S);
mniSetCollegeInfo = new JMenuItem("学校信息");
mniSetStatusBar = new JMenuItem("状态栏信息");
mniChangePassword = new JMenuItem("修改密码");
mniExit = new JMenuItem("退出系统");
// 创建【操作】菜单及其菜单项
mnuOperate = new JMenu("数据操作[O]");
mnuOperate.setMnemonic(KeyEvent.VK_O);
mniAddStudent = new JMenuItem("增加学生表记录");
mnuDelStu = new JMenu("删除学生表记录");
mniEditStudent = new JMenuItem("编辑学生表记录");
mniBrowseStudent = new JMenuItem("浏览学生表记录");
// 创建【删除学生表记录】的子菜单
mniDelStudentById = new JMenuItem("按学号删除");
mniDelStudentsByClass = new JMenuItem("按班级删除");
mniDelStudentsByDepartment = new JMenuItem("按系部删除");
// 创建【查询】菜单及其菜单项
mnuFind = new JMenu("查询学生[Q]");
mnuFind.setMnemonic(KeyEvent.VK_Q);
mniFindStudentById = new JMenuItem("按学号查询");
mniFindStudentsByName = new JMenuItem("按姓名查询");
mniFindStudentsByClass = new JMenuItem("按班级查询");
mniFindStudentsByDepartment = new JMenuItem("按系部查询");
// 创建【统计】菜单及其菜单项
mnuCount = new JMenu("人数统计[C]");
mnuCount.setMnemonic(KeyEvent.VK_C);
mniCountStudentsBySex = new JMenuItem("按性别统计");
mniCountStudentsByClass = new JMenuItem("按班级统计");
mniCountStudentsByDepartment = new JMenuItem("按系部统计");
// 创建【帮助】菜单及其菜单项
mnuHelp = new JMenu("帮助[H]");
mnuHelp.setMnemonic(KeyEvent.VK_H);
mniHelp = new JMenuItem("帮助");
mniAbout = new JMenuItem("关于");
// 创建图标对象
imgCollege = new ImageIcon("images/college.png");
imgPassword = new ImageIcon("images/password.png");
imgQuery = new ImageIcon("images/query.png");
imgBrowse = new ImageIcon("images/browse.png");
imgCount = new ImageIcon("images/count.png");
imgExit = new ImageIcon("images/exit.png");
// 创建工具栏
toolbar = new JToolBar();
btnSetCollege = new JButton("设置学校", imgCollege);
btnSetCollege.setToolTipText("设置学校信息");
btnSetCollege.setVerticalTextPosition(AbstractButton.BOTTOM);
btnSetCollege.setHorizontalTextPosition(AbstractButton.CENTER);
btnChangePassword = new JButton("修改密码", imgPassword);
btnChangePassword.setToolTipText("修改用户密码");
btnChangePassword.setVerticalTextPosition(AbstractButton.BOTTOM);
btnChangePassword.setHorizontalTextPosition(AbstractButton.CENTER);
btnBrowseStudent = new JButton("浏览学生", imgBrowse);
btnBrowseStudent.setToolTipText("浏览学生记录");
btnBrowseStudent.setVerticalTextPosition(AbstractButton.BOTTOM);
btnBrowseStudent.setHorizontalTextPosition(AbstractButton.CENTER);
btnFindStudentById = new JButton("查询学生", imgQuery);
btnFindStudentById.setToolTipText("按学号查询学生记录");
btnFindStudentById.setVerticalTextPosition(AbstractButton.BOTTOM);
btnFindStudentById.setHorizontalTextPosition(AbstractButton.CENTER);
btnCountByDepartment = new JButton("统计人数", imgCount);
btnCountByDepartment.setToolTipText("按系部统计学生人数");
btnCountByDepartment.setVerticalTextPosition(AbstractButton.BOTTOM);
btnCountByDepartment.setHorizontalTextPosition(AbstractButton.CENTER);
btnExit = new JButton("退出系统", imgExit);
btnExit.setToolTipText("退出系统");
btnExit.setVerticalTextPosition(AbstractButton.BOTTOM);
btnExit.setHorizontalTextPosition(AbstractButton.CENTER);
toolbar.add(btnSetCollege);
toolbar.add(btnChangePassword);
toolbar.add(btnBrowseStudent);
toolbar.add(btnFindStudentById);
toolbar.add(btnCountByDepartment);
toolbar.add(btnExit);
// 创建面板
panel = (JPanel) getContentPane();
pnlCenter = new JPanel();
pnlSouth = new JPanel();
pnlSouth.setLayout(new FlowLayout(FlowLayout.LEFT));
// 创建背景图片
imgBackground = new ImageIcon("images/background.jpg");
// 创建背景标签
lblBackground = new JLabel(imgBackground);
// 创建状态栏标签
lblStatusBar = new JLabel();
// 设置菜单栏
setJMenuBar(mnbMain);
// 添加【设置】菜单
mnbMain.add(mnuSet);
mnuSet.add(mniSetCollegeInfo);
mnuSet.add(mniSetStatusBar);
mnuSet.add(mniChangePassword);
mnuSet.addSeparator();
mnuSet.add(mniExit);
// 添加【删除学生表记录】菜单
mnuDelStu.add(mniDelStudentById);
mnuDelStu.add(mniDelStudentsByClass);
mnuDelStu.add(mniDelStudentsByDepartment);
// 添加【操作】菜单
mnbMain.add(mnuOperate);
mnuOperate.add(mniAddStudent);
mnuOperate.add(mniEditStudent);
mnuOperate.add(mnuDelStu);
mnuOperate.add(mniBrowseStudent);
// 添加【查询】菜单
mnbMain.add(mnuFind);
mnuFind.add(mniFindStudentById);
mnuFind.add(mniFindStudentsByName);
mnuFind.add(mniFindStudentsByClass);
mnuFind.add(mniFindStudentsByDepartment);
// 添加【统计】菜单
mnbMain.add(mnuCount);
mnuCount.add(mniCountStudentsBySex);
mnuCount.add(mniCountStudentsByClass);
mnuCount.add(mniCountStudentsByDepartment);
// 添加【帮助】菜单
mnbMain.add(mnuHelp);
mnuHelp.add(mniHelp);
mnuHelp.add(mniAbout);
// 添加面板
panel.setLayout(new BorderLayout());
panel.add(toolbar, "North");
panel.add(pnlCenter, "Center");
panel.add(pnlSouth, "South");
pnlCenter.add(lblBackground);
pnlSouth.add(lblStatusBar);
// 非管理员不能设置状态栏
if (!Application.username.equals("admin")) {
mniSetStatusBar.setEnabled(false);
mniAddStudent.setEnabled(false);
mnuDelStu.setEnabled(false);
mniEditStudent.setEnabled(false);
}
// 设置状态栏信息
setStatusBar();
// 创建状态服务对象
statusService = new StatusServiceImpl();
// 获取状态对象
status = statusService.findStatusById(1);
// 设置窗口尺寸
setSize(800, 640);
// 设置窗口可见
setVisible(true);
// 设置窗口屏幕居中
setLocationRelativeTo(null);
// 设置窗口标题
setTitle("学生信息管理系统" + status.getVersion());
// 注册窗口监听器，继承窗口适配器，编写事件处理方法
addWindowListener(new WindowAdapter() {
@Override
public void windowClosing(WindowEvent e) {
exitSystem();
}
});
// 设置菜单
// 【设置学校信息】菜单项单击事件
mniSetCollegeInfo.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new SetCollegeInfoFrame("");
}
});
// 【设置状态栏信息】菜单项单击事件
mniSetStatusBar.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new SetStatusBarFrame("");
}
});
// 【修改密码】菜单项单击事件
mniChangePassword.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new ChangePasswordFrame("");
}
});
// 【退出系统】菜单项单击事件
mniExit.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
exitSystem();
}
});
// 查询菜单
// 【按学号查询】菜单项单击事件
mniFindStudentById.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new FindStudentByIdFrame("");
}
});
// 【按姓名查询】菜单项单击事件
mniFindStudentsByName.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new FindStudentsByNameFrame("");
}
});
// 【按班级查询】菜单项单击事件
mniFindStudentsByClass.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new FindStudentsByClassFrame("");
}
});
// 【按系部查询】菜单项单击事件
mniFindStudentsByDepartment.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new FindStudentsByDepartmentFrame("");
}
});
// 统计菜单
// 【按性别统计人数】菜单项单击事件
mniCountStudentsBySex.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new CountStudentsBySexFrame("");
}
});
// 【按班级统计人数】菜单项单击事件
mniCountStudentsByClass.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new CountStudentsByClassFrame("");
}
});
// 【按系部统计人数】菜单项单击事件
mniCountStudentsByDepartment.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new CountStudentsByDepartmentFrame("");
}
});
// 【增加学生记录】菜单项单击事件
mniAddStudent.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
new AddStudentFrame("");
}
});
// 【按学号删除学生记录】菜单项单击事件
mniDelStudentById.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new DeleteStudentByIdFrame("");
}
});
// 【按班级删除学生记录】菜单项单击事件
mniDelStudentsByClass.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new DeleteStudentsByClassFrame("");
}
});
// 【按系部删除学生记录】菜单项单击事件
mniDelStudentsByDepartment.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new DeleteStudentsByDepartmentFrame("");
}
});
// 【编辑学生记录】菜单项单击事件
mniEditStudent.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
new EditStudentFrame("");
}
});
// 【浏览学生记录】菜单项单击事件
mniBrowseStudent.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
new BrowseStudentsFrame("");
}
});
// 【帮助】菜单单击事件
mniHelp.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
try {
Runtime.getRuntime().exec("cmd /c start help/帮助文档.chm");
} catch (IOException e1) {
JOptionPane.showMessageDialog(null, e1.getMessage(), "学生信息管理系统", JOptionPane.ERROR_MESSAGE);
}
}
});
// 【关于】菜单单击事件
mniAbout.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(null,
"开发人员：" + status.getCollege() + "_" + status.getAuthor() + "\n联系电话：" + status.getTelephone()
+ "\n电子邮箱：" + status.getEmail(),
"学生信息管理系统" + status.getVersion(), JOptionPane.INFORMATION_MESSAGE);
}
});
// 工具栏按钮单击事件
// 【设置学校信息】按钮
btnSetCollege.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new SetCollegeInfoFrame("");
}
});
// 【修改密码】按钮
btnChangePassword.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new ChangePasswordFrame("");
}
});
// 【浏览】按钮
btnBrowseStudent.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new BrowseStudentsFrame("");
}
});
// 【查询】按钮
btnFindStudentById.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new FindStudentByIdFrame("");
}
});
// 【统计】按钮
btnCountByDepartment.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new CountStudentsByDepartmentFrame("");
}
});
// 【退出】按钮
btnExit.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
exitSystem();
}
});
}
/**
退出系统（询问用户是否要退出）
*/
private void exitSystem() {
int choice = JOptionPane.showConfirmDialog(this,
"您是否要退出系统？","学生信息管理系统", JOptionPane.YES_NO_OPTION);
if (choice == JOptionPane.YES_OPTION) {
System.exit(0);
} else {
// 卸载当前窗口
dispose();
// 重新显示主窗口
Application.mainFrame = new MainFrame("学生信息管理系统" + status.getVersion());
}
}
/**
设置状态栏信息
*/
public void setStatusBar() {
// 创建状态服务对象
statusService = new StatusServiceImpl();
// 获取状态栏对象
status = statusService.findStatusById(1);
// 设置状态栏标签
lblStatusBar.setText(
status.getCollege() + "学生信息管理系统"+ status.getVersion() + " 作者：" + status.getAuthor() + " 地址："
+ status.getAddress() + " 电话：" + status.getTelephone() + " 邮箱：" + status.getEmail());
}
/**
主方法
@param args
*/
public static void main(String[] args) {
Application.mainFrame = new MainFrame("0");
}
}
