用 Java 實現 HTML 檔案替代資料庫儲存資料：Swing 介面完整範例

設計動機

小型圖形化程式需儲存少量資料，用 JDBC 連資料庫過重且慢。改用檔案儲存，並定義為 HTML 表格格式，雙重收益：① 持久化儲存 ② 直接用瀏覽器查看資料。

完整可運行 Swing 範例

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

public class FileWork extends JFrame implements ActionListener {
    JPanel p;
    JButton btnAdd, btnOpen, btnSave;
    JTable table;
    Object[][] data = new Object[50][3];
    int row = 0;
    String[] columns = {"姓名", "年齡", "身高"};

    public FileWork() {
        super("資料循環");
        setSize(300, 300);
        setDefaultCloseOperation(EXIT_ON_CLOSE);

        p = new JPanel();
        table = new JTable(data, columns);
        btnAdd = new JButton("添加");
        btnOpen = new JButton("打開");
        btnSave = new JButton("保存");
        btnAdd.addActionListener(this);
        btnOpen.addActionListener(this);
        btnSave.addActionListener(this);

        p.add(btnAdd); p.add(btnOpen); p.add(btnSave);
        add(new JScrollPane(table), "Center");
        add(p, "South");
        setVisible(true);
    }

    // 打開 HTML 檔案並解析表格資料
    void fileOpen() {
        try {
            JFileChooser chooser = new JFileChooser(".");
            if (chooser.showOpenDialog(this) == JFileChooser.APPROVE_OPTION) {
                BufferedReader in = new BufferedReader(new FileReader(chooser.getSelectedFile() + ""));
                StringBuilder content = new StringBuilder();
                String line;
                while ((line = in.readLine()) != null) content.append(line);
                in.close();

                String html = content.toString();
                int[] start = new int[50], end = new int[50];
                int k = 0, r = 0;
                for (int i = 0; i < 50; i++) {
                    start[i] = html.indexOf("") + 4;
                    end[i] = html.indexOf("");
                    if (start[i] > 3 && end[i] > start[i]) {
                        data[r][k] = html.substring(start[i], end[i]).trim();
                        html = html.substring(end[i] + 5);
                        if (++k == 3) { k = 0; r++; }
                    }
                }
                row = r;
                repaint();
            }
        } catch (Exception e) { e.printStackTrace(); }
    }

    // 將 JTable 資料存為 HTML 表格檔案
    void fileSave() {
        try {
            JFileChooser saver = new JFileChooser(".");
            if (saver.showSaveDialog(null) == JFileChooser.APPROVE_OPTION) {
                OutputStreamWriter out = new OutputStreamWriter(new FileOutputStream(saver.getSelectedFile() + ""));
                StringBuilder html = new StringBuilder();
                html.append("");
                html.append("");
                html.append("");
                for (int i = 0; i < row; i++) {
                    html.append("");
                    html.append("");
                    html.append("");
                    html.append("");
                    html.append("");
                }
                html.append("
姓名
年齡
身高
").append(data[i][0]).append("
").append(data[i][1]).append("
").append(data[i][2]).append("
");
                out.write(html.toString());
                out.close();

                // 清空介面
                for (int i = 0; i < 50; i++) data[i][0] = data[i][1] = data[i][2] = "";
                row = 0;
                repaint();
                JOptionPane.showMessageDialog(null, "保存資料成功!", "Information", JOptionPane.INFORMATION_MESSAGE);
            }
        } catch (Exception e) { e.printStackTrace(); }
    }

    // 添加新資料行
    void addRow() {
        JTextField[] fields = new JTextField[6];
        fields[0] = new JTextField("請輸入姓名："); fields[0].setEditable(false);
        fields[1] = new JTextField();
        fields[2] = new JTextField("請輸入年齡："); fields[2].setEditable(false);
        fields[3] = new JTextField();
        fields[4] = new JTextField("請輸入身高："); fields[4].setEditable(false);
        fields[5] = new JTextField();

        String[] opts = {"確認", "取消"};
        int ret = JOptionPane.showOptionDialog(null, fields, "添加用戶",
                JOptionPane.YES_OPTION, JOptionPane.INFORMATION_MESSAGE, null, opts, opts[0]);
        if (ret == 0) {
            if (fields[1].getText().isEmpty() && fields[3].getText().isEmpty() && fields[5].getText().isEmpty()) {
                JOptionPane.showMessageDialog(null, "資料不能為空", "ERROR", JOptionPane.ERROR_MESSAGE);
            } else {
                data[row][0] = fields[1].getText();
                data[row][1] = fields[3].getText();
                data[row][2] = fields[5].getText();
                row++;
                repaint();
            }
        }
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == btnOpen) fileOpen();
        else if (e.getSource() == btnSave) fileSave();
        else if (e.getSource() == btnAdd) addRow();
    }

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

關鍵技術點

1. HTML 表格解析：簡易字串搜尋 ``/`` 提取儲存格內容
2. HTML 生成：`StringBuilder` 拼接標準 HTML 表格結構
3. Swing 元件：`JTable` 顯示、`JFileChooser` 選檔、`JOptionPane` 對話框
4. 字元編碼：`OutputStreamWriter` 可指定編碼（預設 UTF-8）

優缺點分析

適用場景：桌面小工具、離線資料收集、測試資料導出、教學示範專案。