jishiben.java

本记事本跟window自带功能差不多

import java.awt.*;
import java.awt.event.*;
import java.io.*;

public class FileEdit extends Frame implements ActionListener
{
    String directory;
    TextArea textarea;
    public FileEdit ()
    {
        this(null,null);
    }
    public FileEdit (String filename)
    {
        this(null,filename);
    }
    public FileEdit (String directory,String filename)
    {
        super();
        addWindowListener(new WindowAdapter()
        {
            public void windowClosing(WindowEvent e)
            {
                dispose();
            }
        });
        textarea = new TextArea("",24,80);
        textarea.setFont(new Font("MonoSpced",Font.PLAIN,16));
        textarea.setEditable(true);
        this.add("Center",textarea);
        Panel p = new Panel();
        p.setLayout(new FlowLayout(FlowLayout.RIGHT,10,5));
        this.add(p,"South");

        Font font = new Font("SansSerif",Font.BOLD,14);
        Button openfile = new Button("Open File");
        Button close = new Button("Close");
        Button save = new Button("Save");
        Button saveas = new Button("Save as");
        Button newfile = new Button("New File");

        openfile.addActionListener(this);
        openfile.setActionCommand("open");
        openfile.setFont(font);

        close.addActionListener(this);
        close.setActionCommand("close");
        //close.setMnemonic(KeyEvent.VK_C);
        /*close.addKeyListener(new KeyListener()
        {
            public void keyPressed(KeyEvent e)
            {
                if (e.getKeyCode() == KeyEvent.VK_C)
                {
                    actionPerformed(close.ActionCommand));
                }
            }
            public void keyTyped(KeyEvent e)
            {
            }
            public void keyReleased(KeyEvent e)
            {
            }
        });*/
        close.setFont(font);

        save.addActionListener(this);
        save.setActionCommand("save");
        save.setFont(new Font("SansSerif",Font.BOLD,14));

        saveas.addActionListener(this);
        saveas.setActionCommand("saveas");
        saveas.setFont(new Font("SansSerif",Font.BOLD,14));

        newfile.addActionListener(this);
        newfile.setActionCommand("newfile");
        newfile.setFont(new Font("SansSerif",Font.BOLD,14));

        p.add(newfile);
        p.add(openfile);
        p.add(save);
        p.add(saveas);
        p.add(close);

        this.pack();

        if (directory == null)
        {
            File f;
            if ((filename != null) && (f = new File(filename)).isAbsolute())
            {
                directory = f.getParent();
                filename = f.getName();
                //System.out.println(filename);
            }
            else
            {
                directory = System.getProperty("user.dir");
            }
        }
        this.directory = directory;
        setFile(directory,filename);
    }
    public void setFile(String directory,String filename)
    {
        if ((filename == null) || (filename.length() == 0))
        {
            return;
        }
        File f;
        BufferedReader in = null;
        //FileReader in = null;//FileReader,FileWrite.操作字符流,FileInputStream,FileOnputStream操作字节流
        /*
        *java.io.Reader 和 java.io.InputStream 组成了 Java 输入类。Reader 用于读入16位字符，
        *也就是 Unicode 编码的字符；而 InputStream 用于读入 ASCII 字符和二进制数据。
        */
        try
        {
            f = new File(directory,filename);
            in = new BufferedReader(new FileReader(f));
            char[] buffer = new char[4069];
            int len;
            textarea.setText("");
            while ((len = in.read(buffer)) != -1)
            {
                String s = new String(buffer,0,len);
                textarea.append(s);
            }
            this.setTitle(directory + filename);
            //textarea.append(this.getTitle());
            textarea.setCaretPosition(0);
        }
        catch (IOException e)
        {
            textarea.setText(e.getClass().getName() + ": " + e.getMessage());
            this.setTitle("FileEdit : " + directory + "\\" + filename + ": I/O Exception");
        }
        finally
        {
            try
            {
                if (in != null)
                {
                    in.close();
                }
            }
            catch (IOException e)
            {
            }
        }
    }
    public void saveFile(String directory,String filename,String text)
    {
        if ((filename == null) || (filename.length() == 0))
        {
            return;
        }
        File f;
        BufferedWriter out = null;
        try
        {
            f = new File(directory,filename);
            out = new BufferedWriter(new FileWriter(f));
            out.write(text);
            out.flush();
        }
        catch (IOException e)
        {
            textarea.setText(e.getClass().getName() + ": " + e.getMessage() + "保存文件失败");
            //this.setTitle("FileEeit : " + directory + "\\" + filename + ": I/O Exception");
        }
        finally
        {
            try
            {
                if (out != null)
                {
                    out.close();
                }
            }
            catch (IOException e)
            {
            }
        }
    }

    public void actionPerformed(ActionEvent e)
    {
        String cmd = e.getActionCommand();
        if (cmd.equals("open"))
        {
            FileDialog f = new FileDialog(this,"Open File",FileDialog.LOAD);
            f.setDirectory(directory);
            f.show();
            directory = f.getDirectory();
            setFile(directory,f.getFile());
            f.dispose();
        }
        else if (cmd.equals("close"))
        {
            this.dispose();
        }
        else if (cmd.equals("save"))
        {
            /*FileDialog f = new FileDialog(this,"Save File",FileDialog.LOAD);
            f.setDirectory(directory);
            f.show();
            directory = f.getDirectory();*/
            String filepath = this.getTitle();
            String directory = "",filename = "";
            /*if ((filepath == null) || (filepath.length() == 0))
            {
                return;
            }*/
            int len = filepath.lastIndexOf("\\");
            if (len >= 1)
            {
                directory = filepath.substring(0,len);
                filename = filepath.substring(len + 1);
                saveFile(directory,filename,textarea.getText());
            }
            else
            {
                FileDialog f = new FileDialog(this,"Save File",FileDialog.SAVE);
                f.setDirectory(directory);
                f.show();
                directory = f.getDirectory();
                saveFile(directory,f.getFile(),textarea.getText());
                this.setTitle(directory + f.getFile());
                f.dispose();
            }
            //f.dispose();
        }
        else if (cmd.equals("saveas"))
        {
            FileDialog f = new FileDialog(this,"Save File",FileDialog.SAVE);
            f.setDirectory(directory);
            f.show();
            directory = f.getDirectory();
            saveFile(directory,f.getFile(),textarea.getText());
            f.dispose();
        }
        else if (cmd.equals("newfile"))
        {
            textarea.setText("");
            this.setTitle("");
        }
    }
    public void keyEvent()
    {
    }
    public static void main(String[] args) throws IOException
    {
        //Frame f = new FileEdit ((args.length == 1)?args[0]:null);
        Frame f = new FileEdit ();
        f.addWindowListener(new WindowAdapter()
        {
            public void windowClosed(WindowEvent e)
            {
                System.exit(0);
            }
        });
        f.show();
    }
}