package jishiben;

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Font;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.InputEvent;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.EventQueue;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import javax.swing.BorderFactory;
import javax.swing.JFileChooser;

import javax.swing.JFrame;

import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.KeyStroke;
import javax.swing.ScrollPaneConstants;
import javax.swing.SwingConstants;

import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JSeparator;
import com.jgoodies.forms.factories.DefaultComponentFactory;

public class jishiben extends JFrame {

   private JPanel contentPane;
   private JMenuItem menuOpen;
   private JMenuItem menuSave;
   private JMenuItem menuSaveAs;
   private JMenuItem menuClose;
   private JMenu editMenu;
   private JMenuItem menuCut;
   private JMenuItem menuCopy;
   private JMenuItem menuPaste;
   private JMenuItem menuAbout;

   private JTextArea textArea;
   private JLabel stateBar;
   private JFileChooser fileChooser;

   private JPopupMenu popUpMenu;
   /**
   * Launch the application.
   */

       public static void main(String[] args) {
           EventQueue.invokeLater(new Runnable() {
               public void run() {
                   try {
                       jishiben frame = new jishiben();
                       frame.setUpEventListener();
                       frame.setVisible(true);
                   } catch (Exception e) {
                       e.printStackTrace();
                   }
               }
           });

       }
   /**
   * Create the frame.
   */
   public jishiben() {
       setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       setBounds(100, 100, 450, 300);

       JMenuBar menuBar = new JMenuBar();
       setJMenuBar(menuBar);

       JMenu fileMenu = new JMenu("文件");
       menuBar.add(fileMenu);

       JMenuItem menuOpen = new JMenuItem("打开");
       fileMenu.add(menuOpen);

       JSeparator separator = new JSeparator();
       fileMenu.add(separator);

       JMenuItem menuSave = new JMenuItem("保存");
       fileMenu.add(menuSave);

       JMenuItem menuSaveAs = new JMenuItem("另存为");
       fileMenu.add(menuSaveAs);

       JSeparator separator_1 = new JSeparator();
       fileMenu.add(separator_1);

       JMenuItem menuClose = new JMenuItem("关闭");
       fileMenu.add(menuClose);

       JMenu editSave = new JMenu("编辑");
       menuBar.add(editSave);

       JMenuItem menuCut = new JMenuItem("剪切");
       editSave.add(menuCut);

       JMenuItem menuCopy = new JMenuItem("复制");
       editSave.add(menuCopy);

       JMenuItem menuPaste = new JMenuItem("粘贴");
       editSave.add(menuPaste);

       JMenu aboutMenu = new JMenu("关于");
       menuBar.add(aboutMenu);

       JMenuItem menuAbout = new JMenuItem("关于JNotePad");
       aboutMenu.add(menuAbout);
       contentPane = new JPanel();
       contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
       contentPane.setLayout(new BorderLayout(0, 0));
       setContentPane(contentPane);

       JPanel panel = new JPanel();
       contentPane.add(panel, BorderLayout.CENTER);

       JTextArea textArea = new JTextArea();
       textArea.setRows(8);
       textArea.setColumns(50);
       panel.add(textArea);

       JLabel stateBar = DefaultComponentFactory.getInstance().createTitle("\u672A\u4FEE\u6539");
       contentPane.add(stateBar, BorderLayout.SOUTH);
   }
   private void setUpEventListener() {
   // 按下窗口关闭钮事件处理
   addWindowListener(new WindowAdapter() {public void windowClosing(WindowEvent e) {closeFile();}});
   // 菜单 - 打开
   menuOpen.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {openFile();}});
   // 菜单 - 保存
   menuSave.addActionListener(
           new ActionListener() {
           public void actionPerformed(ActionEvent e) {
           saveFile();
           }});
   // 菜单 - 另存为
   menuSaveAs.addActionListener(
   new ActionListener() {
   public void actionPerformed(ActionEvent e) {
   saveFileAs();
   }});
   // 菜单 - 关闭文件
   menuClose.addActionListener(
   new ActionListener() {
   public void actionPerformed(ActionEvent e) {
   closeFile();
   }});
   // 菜单 - 剪切
   menuCut.addActionListener(
   new ActionListener() {
   public void actionPerformed(ActionEvent e) {
   cut();
   }});
   // 菜单 - 复制
   menuCopy.addActionListener(
   new ActionListener() {
   public void actionPerformed(ActionEvent e) {
   copy();
   }});
   // 菜单 - 粘贴
   menuPaste.addActionListener(
           new ActionListener() {
           public void actionPerformed(ActionEvent e) {
           paste();
           }});

           // 菜单 - 关于
           menuAbout.addActionListener(
           new ActionListener() {
           public void actionPerformed(ActionEvent e) {
           // 显示对话框
           JOptionPane.showOptionDialog(null,
           "程序名称:\n JNotePadUI \n" +
           "程序设计:\n \n" +
           "简介:\n 一个简单的文字编辑器\n" +
           " 可作为验收 Java 的实现对象\n" +
           " /"," 关于 JNotePadUI", JOptionPane.DEFAULT_OPTION,
           JOptionPane.INFORMATION_MESSAGE, null, null, null);
           }});
           // 编辑区键盘事件
           textArea.addKeyListener(
           new KeyAdapter() {
           public void keyTyped(KeyEvent e) {
           processTextArea();
           }});
           // 编辑区鼠标事件
           textArea.addMouseListener(
           new MouseAdapter() {
           public void mouseReleased(MouseEvent e) {
           if(e.getButton() == MouseEvent.BUTTON3)
           popUpMenu.show(editMenu, e.getX(), e.getY());
           }
           public void mouseClicked(MouseEvent e) {
           if(e.getButton() == MouseEvent.BUTTON1)
           popUpMenu.setVisible(false);
           }});

   }
   private void openFile() {
       if(isCurrentFileSaved()) { // 文件是否为保存状态
           open(); // 打开
       }
       else {
       // 显示对话框
           int option = JOptionPane.showConfirmDialog(null, "文件已修改，是否保存？", "保存文件？", JOptionPane.YES_NO_OPTION,JOptionPane.WARNING_MESSAGE, null);
           switch(option) {
           // 确认文件保存
           case JOptionPane.YES_OPTION:
               saveFile(); // 保存文件
               break;
               // 放弃文件保存
           case JOptionPane.NO_OPTION:
               open();
               break;
           }
       }
   }
   private boolean isCurrentFileSaved() {
       if(stateBar.getText().equals("未修改")) {
           return false;
       }
       else {
           return true;
       }
   }
   private void open() {
       // fileChooser 是 JFileChooser 的实例
       // 显示文件选取的对话框
       int option = fileChooser.showDialog(null, null);

       // 使用者按下确认键
       if(option == JFileChooser.APPROVE_OPTION) {
       try {
       // 开启选取的文件
       BufferedReader buf =
       new BufferedReader(
       new FileReader(
       fileChooser.getSelectedFile()));
       // 设定文件标题
       setTitle(fileChooser.getSelectedFile().toString());
       // 清除前一次文件
       textArea.setText("");
       // 设定状态栏
       stateBar.setText("未修改");
       // 取得系统相依的换行字符
       String lineSeparator = System.getProperty("line.separator");
       // 读取文件并附加至文字编辑区
       String text;
       while((text = buf.readLine()) != null) {
       textArea.append(text);
       textArea.append(lineSeparator);
       }
       buf.close();
       } catch(IOException e) {
       JOptionPane.showMessageDialog(null,
       e.toString(),
       "开启文件失败", JOptionPane.ERROR_MESSAGE);
       } } }
       private void saveFile() {
       // 从标题栏取得文件名称
       File file = new File(getTitle());
       // 若指定的文件不存在
       if(!file.exists()) {
       // 执行另存为
       saveFileAs();
       } else {
       try {
       // 开启指定的文件
       BufferedWriter buf =
       new BufferedWriter(
       new FileWriter(file));
       // 将文字编辑区的文字写入文件
       buf.write(textArea.getText());
       buf.close();
       // 设定状态栏为未修改
       stateBar.setText("未修改");
       } catch(IOException e) {
       JOptionPane.showMessageDialog(null, e.toString(),
       "写入文件失败", JOptionPane.ERROR_MESSAGE);
       } } }
   private void saveFileAs() {
           // 显示文件对话框
           int option = fileChooser.showSaveDialog(null);
           // 如果确认选取文件
           if(option == JFileChooser.APPROVE_OPTION) {
           // 取得选择的文件
           File file = fileChooser.getSelectedFile();

// 在标题栏上设定文件名称
setTitle(file.toString());

           try {
           // 建立文件
           file.createNewFile();
           // 进行文件保存
           saveFile();
           } catch(IOException e) {
           JOptionPane.showMessageDialog(null, e.toString(),
           "无法建立新文件", JOptionPane.ERROR_MESSAGE);
           } } }
   private void closeFile() {
       // 是否已保存文件
       if(isCurrentFileSaved()) {
       // 释放窗口资源，而后关闭程序
       dispose();
       } else {
       int option = JOptionPane.showConfirmDialog(
       null, "文件已修改，是否保存？",
       "保存文件？", JOptionPane.YES_NO_OPTION,
       JOptionPane.WARNING_MESSAGE, null);
       switch(option) {
       case JOptionPane.YES_OPTION:
       saveFile();
       break;
       case JOptionPane.NO_OPTION:
       dispose();
       } } }
   private void cut() {
       textArea.cut();
       stateBar.setText("已修改");
       popUpMenu.setVisible(false);
       }
   private void copy() {
       textArea.copy();
       popUpMenu.setVisible(false);
       }
   private void paste() {
       textArea.paste();
       stateBar.setText("已修改");
       popUpMenu.setVisible(false);
       }
   private void processTextArea() {
       stateBar.setText("已修改"); }
}

java.lang.NullPointerException
   at jishiben.jishiben.setUpEventListener(jishiben.java:150)
   at jishiben.jishiben$1.run(jishiben.java:73)
   at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:316)
   at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:770)
   at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
   at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
   at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
   at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
   at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:740)
   at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
   at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
   at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
   at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
   at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
   at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

ajax请求返回数据保存为全局变量

wendy_shaoqian

4个回复