為你的Java代碼大量設定頭注釋

大多正式一點的Java原始碼，在頭部都設有頭注釋資訊，其中包含一些著作權聲明等資訊。例如JDK的源碼一般如下：

/*
 * @(#)Object.java 1.61 03/01/23
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package java.lang;

public class Object { .....}

如果我們有個小工具能把我們項目裡所有目錄下的Java代碼統一設定頭注釋就好了；比如當版本資訊等改變時，只要重新運行一下即可一次性更新。下面我們就來親自寫一個。

思路很簡單：

1. 建立一個視窗，使用者可以設定一個目錄、編寫頭注釋資訊；
2. 尋找目錄下所有子檔案，如果是Java檔案則處理之，如果是目錄則遞迴處理；
3. 處理Java檔案時，開啟後，找到package語句或者第一個import語句，作為注釋的插入點，插入注釋；
4. 將增加了頭注釋的檔案內容寫迴文件。

本例中判斷頭注釋插入點的邏輯比較簡單，只是根據package語句或者第一個import語句來判斷注釋插入點，尚不嚴謹（比如原有的頭注釋中可能包含這些關鍵字），僅供參考。

源碼如下：

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

public class HeaderCommentsGenerator {
    private static int count = 0;

    public static void main(String[] args) {
        final JFrame frame = new JFrame("HeaderCommentsGenerator 1.0 [xiaozhonghua@hotmail.com]");
        JPanel contentPane = (JPanel) frame.getContentPane();
        JPanel centerPane = new JPanel(new BorderLayout(10, 10));
        centerPane.setBorder(BorderFactory.createEmptyBorder(10, 10, 0, 10));
        JPanel pathPane = new JPanel(new BorderLayout());
        final JTextField txtPath = new JTextField();
        txtPath.setText("Please select your file or path.");
        pathPane.add(txtPath, BorderLayout.CENTER);
        JButton btnSelectPath = new JButton("Browser...");
        btnSelectPath.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                JFileChooser chooser = new JFileChooser();
                chooser.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);
                int returnVal = chooser.showOpenDialog(frame);
                if (returnVal == JFileChooser.APPROVE_OPTION) {
                    txtPath.setText(chooser.getSelectedFile().getAbsolutePath());
                }
            }
        });
        btnSelectPath.setMnemonic('B');
        pathPane.add(btnSelectPath, BorderLayout.EAST);
        centerPane.add(pathPane, BorderLayout.NORTH);
        final JTextArea txtComments = new JTextArea();
        txtComments.setText("/*/n" +
                            " * Copyright 2003-2004 ABC Software, Inc. All rights reserved./n" +
                            " */");
        centerPane.add(new JScrollPane(txtComments), BorderLayout.CENTER);

        contentPane.add(centerPane, BorderLayout.CENTER);

        JPanel buttonPane = new JPanel(new FlowLayout(FlowLayout.RIGHT, 10, 10));
        JButton btnOK = new JButton("Generate!");
        btnOK.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String path = txtPath.getText();
                File file = new File(path);
                if (!file.exists()) {
                    JOptionPane.showMessageDialog(frame,
                                                  "Path '" + path + "' not exist.",
                                                  "Error",
                                                  JOptionPane.ERROR_MESSAGE);
                } else {
                    commentFile(file, txtComments.getText());
                    JOptionPane.showMessageDialog(frame,
                                                  "Finish, total " + count + " files are processed.",
                                                  "Information",
                                                  JOptionPane.INFORMATION_MESSAGE);
                }
            }
        });
        btnOK.setMnemonic('G');
        JButton btnClose = new JButton("Close");
        btnClose.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                System.exit(0);
            }
        });
        btnClose.setMnemonic('C');
        buttonPane.add(btnOK);
        buttonPane.add(btnClose);
        contentPane.add(buttonPane, BorderLayout.SOUTH);

        frame.setSize(500, 300);
        frame.show();
    }

    private static void commentFile(File file, String comments) {
        if (file != null && file.exists()) {
            if (file.isDirectory()) {
                String[] children = file.list();
                for (int i = 0; i < children.length; i++) {
                    File child = new File(file.getPath() + System.getProperty("file.separator") + children[i]);
                    commentFile(child, comments);
                }
            } else {
                if (file.getName().toLowerCase().endsWith(".java")) {
                    System.out.println(file.getName());
                    count++;
                    try {
                        RandomAccessFile raFile = new RandomAccessFile(file, "rw");
                        byte[] content = new byte[ (int) raFile.length()];
                        raFile.readFully(content);
                        String all = new String(content);
                        all = all.trim();
                        while (all.startsWith("/n")) {
                            all = all.substring(1);
                        }
                        if (all.indexOf("package") != -1) {
                            all = all.substring(all.indexOf("package"));
                        }
                        if (all.indexOf("import") != -1) {
                            all = all.substring(all.indexOf("package"));
                        }
                        all = comments + "/n" + all;
                        raFile.close();
                        FileWriter writer = new FileWriter(file);
                        writer.write(all);
                        writer.close();
                    }
                    catch (Exception ex) {
                        ex.printStackTrace();
                    }
                }
            }
        }
    }
}

希望這個小工具對你有點用處。