简易记事本，刚打开的时候光标在button上，哪位大虾帮忙解决下，感激不尽 .

//package note;import java.awt.BorderLayout;import java.awt.Cursor;import java.awt.FlowLayout;import java.awt.Font;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.KeyAdapter;import java.awt.event.KeyEvent;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;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.JButton;import javax.swing.JFileChooser;import javax.swing.JFrame;import javax.swing.JOptionPane;import javax.swing.JPanel;import javax.swing.JScrollPane;import javax.swing.JTextArea;//因为JTextArea不是继承TextArea，所以没有addTextListener方法，选用键盘监听//要对窗口，按钮，文本进行监听，如果都继承的话，WindowListener和KeyListener有很多方法要重写//而ActionListener只有一个方法要重写，所以选择窗口匿名内部类，继承KeyAdapter，实现ActionListenerpublic class Note2 extends KeyAdapter implements ActionListener{//明确变量private JFrame frame;private JTextArea text;private JPanel panel;private JButton open,newFile,save,saveAs,about;private String textName;private String fpath;private String fname;private Boolean textChange=false;private Boolean openTrueNewFalse=false;public Note2(){frame=new JFrame();text=new JTextArea();panel=new JPanel();open=new JButton("打开");newFile=new JButton("新建");save=new JButton("保存");saveAs=new JButton("另存为");about=new JButton("关于");textName="无标题 - 小事本";}public void displayWindow(){frame.setTitle(textName);frame.setSize(600,400);frame.setLocation(300,200);frame.setDefaultCloseOperation(javax.swing.WindowConstants.DO_NOTHING_ON_CLOSE);text.setFont(new Font("Fixedsys",0,18));text.setLineWrap(true);text.setWrapStyleWord(true);text.setCursor(new Cursor(2));//可以改变光标的形状panel.setLayout(new FlowLayout(FlowLayout.LEFT));save.setEnabled(false);saveAs.setEnabled(false);panel.add(open);panel.add(newFile);panel.add(save);panel.add(saveAs);panel.add(about);frame.add(new JScrollPane(text));frame.add(panel,BorderLayout.NORTH);//这是哪个类里找到的方法open.addActionListener(this); newFile.addActionListener(this);about.addActionListener(this);save.addActionListener(this);saveAs.addActionListener(this);text.addKeyListener(this);frame.addWindowListener(new WindowAdapter()//匿名内部类，很不懂,所以只用了一个   {    public void windowClosing(WindowEvent e)    {    if(textChange){    int option=JOptionPane.showConfirmDialog(frame, "文件内容已经改变，是否保存？");if(option==JOptionPane.YES_OPTION){saveText();if(!textChange){System.exit(0);}} else if(option==JOptionPane.NO_OPTION){System.exit(0);} else if(option==JOptionPane.CANCEL_OPTION){//点取消的话窗口关闭系统不关闭，预想效果窗口系统都不关闭//解决方法：frame.setDefaultCloseOperation(javax.swing.WindowConstants.DO_NOTHING_ON_CLOSE);}    } else {    System.exit(0);    }    }   }     );frame.setVisible(true);}public void actionPerformed(ActionEvent ae) {if(ae.getActionCommand()=="打开"){this.openText();}else if(ae.getActionCommand()=="新建"){this.creatNewText();}else if(ae.getActionCommand()=="保存"){this.saveText();}else if(ae.getActionCommand()=="另存为"){this.saveAnthorText();}else if(ae.getActionCommand()=="关于"){String message = "   ----小事本----\n   版本：Version 2.0\n   感谢您的使用!";         JOptionPane.showMessageDialog(frame, message, "关于...",JOptionPane.PLAIN_MESSAGE);}}//打开private void openText() {if(textChange){int option=JOptionPane.showConfirmDialog(frame, "文件内容已经改变，是否保存？");if(option==JOptionPane.YES_OPTION){this.saveText();//之前是新建，弹出另存为，没有选择保存，判断是否保存，是打开对话框，否什么都不做if(!textChange){this.openDialog();}} else if(option==JOptionPane.NO_OPTION){this.openDialog();}} else {this.openDialog();}}//打开对话框，打开方法中用到private void openDialog() {JFileChooser fchooser=new JFileChooser();int result=fchooser.showDialog(frame,"打开");if(result==JFileChooser.APPROVE_OPTION){File file=fchooser.getSelectedFile();fpath=file.getAbsolutePath();fname=file.getName();textName=fname+" - 小事本";frame.setTitle(textName);text.setText("");BufferedReader br=null;String line;try{br=new BufferedReader(new FileReader(file));while((line=br.readLine())!=null){text.append(line+System.getProperty("line.separator"));}}catch(Exception e ){}finally{textChange=false;this.openTrueNewFalse=true;try{br.close();}catch(IOException e){}}}}//新建private void creatNewText() {if(textChange){int option=JOptionPane.showConfirmDialog(frame, "文件内容已经改变，是否保存？");if(option==JOptionPane.YES_OPTION){this.saveText();//这里要判断下是否保存,如果保存，textChange为falseif(!textChange){this.textName="无标题 - 小事本";//“打开”的时候这个变量会改变frame.setTitle(textName);text.setText("");save.setEnabled(false);saveAs.setEnabled(false);this.openTrueNewFalse=false;}} else if(option==JOptionPane.NO_OPTION){this.textName="无标题 - 小事本";//“打开”的时候这个变量会改变frame.setTitle(textName);text.setText("");save.setEnabled(false);saveAs.setEnabled(false);this.openTrueNewFalse=false;textChange=false;}} else {this.textName="无标题 - 小事本";//“打开”的时候这个变量会改变frame.setTitle(textName);text.setText("");save.setEnabled(false);saveAs.setEnabled(false);this.openTrueNewFalse=false;}}//保存private void saveText() {//判断之前是打开还是新建if(openTrueNewFalse){BufferedWriter bw=null;try{bw=new BufferedWriter(new FileWriter(fpath));bw.write(text.getText());bw.flush();}catch(Exception e ){}finally{textChange=false;try{bw.close();}catch(IOException e){}}} elsethis.saveAnthorText();}//另存为private void saveAnthorText() {JFileChooser fchooser=new JFileChooser();int result=fchooser.showDialog(frame,"另存为");if(result==JFileChooser.APPROVE_OPTION){File file=fchooser.getSelectedFile();BufferedWriter bw=null;try{bw=new BufferedWriter(new FileWriter(file));bw.write(text.getText(), 0, text.getText().length());bw.flush();}catch(Exception e ){}finally{textChange=false;try{bw.close();}catch(IOException e){}}}}public void keyPressed(KeyEvent ke) {textChange=true;save.setEnabled(true);saveAs.setEnabled(true);}public static void main(String[] args){Note2 note2=new Note2();note2.displayWindow();}}