/**java实现记事本功能*/import java.awt.*;import java.awt.event.*;import java.io.*;public class Java{private Frame fr;private TextArea ta;private MenuBar bar;private Menu m;private MenuItem mi1,mi2,mi3,mi4,mi5;private Font font;private Dialog dia;private Button but1,but2;private FileDialog fd1,fd2;private File file = null;Java(){init();}public void init(){fr = new Frame("我的记事本");ta = new TextArea();bar = new MenuBar();m = new Menu("file");mi1 = new MenuItem("new");mi2 = new MenuItem("open");mi3 = new MenuItem("save");mi4 = new MenuItem("save as");mi5 = new MenuItem("exit");but1 = new Button("是");but2 = new Button("否");fd1 = new FileDialog(fr,"File",FileDialog.LOAD );fd2 = new FileDialog(fr,"File",FileDialog.SAVE );font = new Font("Monospaced" ,Font.BOLD,20);//新建一个字体对象dia = new Dialog(fr,"是否保存？",true);dia.setLayout(new FlowLayout());dia.setBounds(530, 280, 140, 100);fr.setBounds(200, 80, 700, 600);fr.add(ta);fr.setFont(font);//设置字体m.add(mi1);m.add(mi2);m.add(mi3);m.add(mi4);m.add(mi5);bar.add(m);fr.setMenuBar(bar);dia.add(but1);dia.add(but2);myEvent();fr.setVisible(true);}public void myEvent(){fr.addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent e){System.exit(0);}});//新建一个文件mi1.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){ta.setText("");}});//打开一个文件mi2.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){fd1.setVisible(true);String dirPath = fd1.getDirectory();//返回次对话框的目录String fileName = fd1.getFile();//获取此文件对话框的选定文件if(dirPath==null&&fileName==null)return ;//下面的程序不运行ta.setText("");file = new File(dirPath,fileName);try{BufferedReader bufr = new BufferedReader(new FileReader(file));String str = null;while((str = bufr.readLine())!=null){ta.append(str +"\r\n");}bufr.close();//资源必须关闭}catch(IOException ex){throw new RuntimeException("流无法读取");}}});//保存mi3.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){saveMethod();}});mi4.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){fd2.setVisible(true);String dirPath = fd2.getDirectory();//返回次对话框的目录String fileName = fd2.getFile();//获取此文件对话框的选定文件if(dirPath==null&&fileName==null)//判断是否取消return ;//下面的程序不运行//ta.setText(" ");file = new File(dirPath,fileName);try{BufferedWriter bufw = new BufferedWriter(new FileWriter(file));String str = ta.getText();bufw.write(str);bufw.close();}catch(IOException ed){throw new RuntimeException("写入流出现异常");}}});//退出mi5.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){String str = ta.getText();if(str.equals(""))System.exit(0);else{dia.setVisible(true);}}});but1.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){saveMethod();}});but2.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){System.exit(0);}});ta.addKeyListener(new KeyAdapter() {public void keyPressed(KeyEvent e){//ctrl和S同时按下if((e.isControlDown())&&(e.getKeyCode() == e.VK_S)){saveMethod();}}});}public void saveMethod(){if(file==null){//文件为空，那么文件对话框就会跳出来fd2.setVisible(true);String dirPath = fd2.getDirectory();//返回次对话框的目录String fileName = fd2.getFile();//获取此文件对话框的选定文件if(dirPath==null&&fileName==null)//判断是否取消return ;//下面的程序不运行file = new File(dirPath,fileName);}try{BufferedWriter bufw = new BufferedWriter(new FileWriter(file));String str = ta.getText();bufw.write(str);bufw.close();}catch(IOException ed){throw new RuntimeException("写入流出现异常");}}public static void main(String[] args) {new Java();}}
