java - 影响 JTable 单元格值在文本文件上的更改

Question

我使用这种方法来更改我的表格单元格值， 它在 jtable 上改变但在文本文件上没有改变!

public class user_AllBooks extends AbstractTableModel {

    BookInformation book_info = new BookInformation();
    String[] columns = new String[]{"Book Name", "Book Date", "Book ID", "Borrow Status"};
    ArrayList<BookInformation> bData = new ArrayList<BookInformation>();

    public user_AllBooks() {
        try {
            BufferedReader br = new BufferedReader(new FileReader("AllBookRecords.txt"));
            String line;
            while ((line = br.readLine()) != null) {
                bData.add(initializeBookData(line));
            }
            br.close();
        } catch (IOException ioe) {
        }
    }

    public BookInformation initializeBookData(String myline) {
        BookInformation book_infos = new BookInformation();
        String[] celledLine = myline.split("     ");
        book_infos.setBookName(celledLine[0]);
        book_infos.setBookDate(celledLine[1]);
        book_infos.setBookID(celledLine[2]);
        book_infos.setBorrowStatus(celledLine[3]);
        return book_infos;
    }

    @Override
    public String getColumnName(int col) {
        return columns[col];
    }

    @Override
    public int getRowCount() {
        if (bData != null) {
            return bData.size();
        } else {
            return 0;
        }
    }

    @Override
    public int getColumnCount() {
        return columns.length;
    }

    @Override
    public Object getValueAt(int rowIndex, int columnIndex) {
        BookInformation bookInf = bData.get(rowIndex);
        Object value;

        switch (columnIndex) {
            case 0:
                value = bookInf.getBookName();
                break;
            case 1:
                value = bookInf.getBookDate();
                break;
            case 2:
                value = bookInf.getBookID();
                break;
            case 3:
                value = bookInf.getBorrowStatus();
                break;
            default:
                value = "...";
        }
        return value;
    }


    @Override
  public void setValueAt(Object value, int row, int col)
    {
    BookInformation book_infos = bData.get(row);
    if (col==0)
    book_infos.setBookName((String)value);
    else if (col==1)
    book_infos.setBookDate((String)value);
    else if (col==2)
    book_infos.setBookID((String)value);
    else if (col==3)
    book_infos.setBorrowStatus((String)value);
    }
    }

第二类:

public class user_AllBooksM extends JFrame implements ActionListener {

    user_AllBooks uAllBooks = new user_AllBooks();
    final JTable bTable = new JTable(uAllBooks);
    JButton borrowButton;

    public user_AllBooksM() {
        setTitle("All Books");
        exitButton = new JButton("Exit");
        borrowButton = new JButton("Borrow");
        borrowButton.addActionListener(this);
        JPanel Bpanel = new JPanel();
        Bpanel.setLayout(new FlowLayout());
        JScrollPane sp = new JScrollPane(bTable);
        Bpanel.add(sp);
        Bpanel.add(borrowButton);
        this.add(Bpanel);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setBounds(300, 60, 550, 550);
        this.setResizable(false);
        this.setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent event) {
        borrowInitialize(bTable.getSelectedRow());
    }

    public void borrowInitialize(int row) {
        if (uAllBooks.getValueAt(row, 3).equals("yes")) {
            JOptionPane.showMessageDialog(null, "This Book Was Borrowed");
        } else {
            uAllBooks.setValueAt("Yes", row, 3);
            uAllBooks.fireTableRowsUpdated(row, row);
        }
    }

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

我的文本文件:

sds wew     88     77     no
moon     889     988     yes
ccc     30     33     no
testing     76     77     no
yes     999     444     no
hoop     100     200     no
name     60     20     no
pp     14     15     no
vbnet     49     94     yes
sdsd     232     dsds     no
gh     12     21     no
khoyBook     322     233     no

Answer 1

将 TableModelListener 添加到您的 TableModel。然后，无论何时首先发生更新事件，您都需要遍历 TableModel 的行/列并重新创建文本文件。

您的 TableModel 实现不正确。您还没有实现 setValueAt(...) 方法。

应从 TableModel 的 setValueAt() 方法调用“fireTableRowsUpdated()”方法。它不应从您的 ActionListener 代码中调用。