java记事本

package notepad;import java.awt.*;import javax.swing.*;import java.awt.event.*;import java.io.*;public class Notepad extends JFrame implements ActionListener{JMenuBar menu=null;JMenu wenjian,bianji;JMenuItem a1,a2,a3,a4,b1,b2,b3,b4;JTextArea wbk=null;public static void main(String[] args) {Notepad pad=new Notepad();}public Notepad(){menu=new JMenuBar();wenjian=new JMenu("文件");a1=new JMenuItem("打开");a2=new JMenuItem("保存");a3=new JMenuItem("另存为");a4=new JMenuItem("新建");bianji=new JMenu("编辑");b1=new JMenuItem("剪切");b2=new JMenuItem("复制");b3=new JMenuItem("粘贴");b4=new JMenuItem("清空");wbk=new JTextArea();wenjian.add(a4);wenjian.add(a1);wenjian.add(a2);wenjian.add(a3);bianji.add(b1);bianji.add(b2);bianji.add(b3);bianji.add(b4);menu.add(wenjian);menu.add(bianji);this.setVisible(true);this.setSize(500, 600);this.setLocation(400, 60);this.setTitle("记事本");this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);this.setJMenuBar(menu);this.add(wbk);a1.addActionListener(this);a1.setActionCommand("a1");a2.addActionListener(this);a2.setActionCommand("a2");a3.addActionListener(this);a3.setActionCommand("a3");a4.addActionListener(this);a4.setActionCommand("a4");b3.addActionListener(this);b3.setActionCommand("b3");b4.addActionListener(this);b4.setActionCommand("b4");}public void actionPerformed(ActionEvent e) {if(e.getActionCommand().equals("a1")){JFileChooser wjxz=new JFileChooser();wjxz.setDialogTitle("选择文件");wjxz.showOpenDialog(null);wjxz.setVisible(true);String lujing=wjxz.getSelectedFile().getAbsolutePath();FileReader read=null;BufferedReader read1=null;try{read=new FileReader(lujing);read1=new BufferedReader(read);String s="",d="";while((s=read1.readLine())!=null)d+=(s+"\n");wbk.setText(d);}catch(Exception e1){}finally{try{read.close();read1.close();}catch(Exception e2){}}}else if(e.getActionCommand().equals("a3")){JFileChooser wjbc=new JFileChooser();wjbc.setDialogTitle("另存为");wjbc.showSaveDialog(null);wjbc.setVisible(true);String lujing2=wjbc.getSelectedFile().getAbsolutePath();PrintStream p1=null;try{p1=new PrintStream(lujing2);System.setOut(p1);System.out.println(this.wbk.getText());}catch(Exception e3){}finally{try{p1.close();}catch(Exception e4){}}}else if(e.getActionCommand().equals("a4")){if(this.wbk.getText().equals("")){this.wbk.setText(null);}else{JOptionPane jo;jo = new JOptionPane();jo.showMessageDialog(null,"提示："+"\n"+"请先保存文件再清空！");}}else if(e.getActionCommand().equals("a2")){String lujing="C:\\Users\\kangbiao\\Desktop";PrintStream p1=null;try{p1=new PrintStream(lujing);System.setOut(p1);System.out.println(this.wbk.getText());}catch(Exception e3){}finally{try{p1.close();}catch(Exception e4){}}}else if(e.getActionCommand().equals("b4")){this.wbk.setText(null);}}}