java实现记事本

来源：互联网发布：长虹大数据公司编辑：程序博客网时间：2024/06/06 18:24

首先，制作记事本的可视化界面，用于记事本的编辑；其次，记事本文件的操作如打开、关闭、保存；最后，记事本文件内容的读写涉及IO操作。

package fileeditor;

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

public class FileEditor extends JFrame {


    private JTextField selectField;


    private JTextArea editArea;


    private JButton saveBtn;


    private JButton openFileBtn;


    private int level = 0;

    public FileEditor() {
        this.init();
    }

    private void init() {


        this.setTitle("Editor");


        this.setBounds(300, 50, 600, 650);


        selectField = new JTextField(40);


        openFileBtn = new JButton("Browse");


        openFileBtn.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent ae) {
                FileEditor.this.level = 0;
                String path = selectField.getText();


                openDirOrFile(path.replaceAll("//", "\\\\"));

            }
        });

        JPanel upPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));


        upPanel.setBackground(Color.CYAN);


        upPanel.add(selectField);


        upPanel.add(openFileBtn);


        this.add(upPanel, BorderLayout.NORTH);

        editArea = new JTextArea();
        ScrollPane scollPanel = new ScrollPane(ScrollPane.SCROLLBARS_AS_NEEDED);
        scollPanel.add(editArea);
        this.add(scollPanel, BorderLayout.CENTER);

        saveBtn = new JButton("Save");
        saveBtn.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent ae) {
                saveFile();
            }
        });

        JPanel southPanel = new JPanel();
        southPanel.setBackground(Color.green);
        southPanel.add(saveBtn);
        this.add(southPanel, BorderLayout.SOUTH);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setVisible(true);
    }


    private void saveFile() {
        FileDialog fd = new FileDialog(this, "Save File");


        fd.setFile("untitled.txt");


        fd.setMode(FileDialog.SAVE);
        fd.setVisible(true);


        String fileName = fd.getFile();


        String dir = fd.getDirectory();


        File newFile = new File(dir + File.separator + fileName);
        PrintWriter pw = null;
        try {
            pw = new PrintWriter(new OutputStreamWriter(new FileOutputStream(
                    newFile)));

            String str = editArea.getText();
            pw.println(str);
            pw.flush();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            pw.close();
        }
    }


    private void openDirOrFile(String absolutePath) {


        File file = new File(absolutePath);


        if (!(file.exists())) {
            editArea.setText("The file does not exist!");


        } else if (file.isDirectory()) {
            editArea.setText(null);
            showDir(file);

        } else if (file.isFile()) {
            try {
                FileInputStream fis = new FileInputStream(file);
                BufferedReader br = new BufferedReader(new InputStreamReader(
                        fis));
                String str = null;
                editArea.setText(null);
                while ((str = br.readLine()) != null) {
                    editArea.append(str + "\r\n");
                }
                br.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    private void showDir(File directory)
    {
        File[] files = directory.listFiles();
        int len = files.length;
        for(int i = 0; i < len; i++)
        {
            if(files[i].isDirectory())
            {
                for(int j = 0; j < this.level; j++)
                {
                    editArea.append("    ");
                }
                editArea.append("|-- "+ files[i].getName() + " (Folder)\r\n");
                this.level++;
                showDir(files[i]);
                this.level--;
            }
            else if(files[i].isFile())
            {
                for(int j = 0; j < this.level; j++)
                {
                    editArea.append("    ");
                }
                editArea.append("|-- " + files[i].getAbsolutePath() + "\r\n");
            }
        }
    }

    public static void main(String[] args) {
        new FileEditor();
    }
}

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