如何使单选按钮更改表格数据

Question

我正在制作一个添加学生和教师数据的程序。我想通过选择单选按钮在表格上为学生或老师显示数据

public void paneling(){
    panell = new JPanel(new BorderLayout());
    DefaultTableModel model = new DefaultTableModel();
        JTable table = new JTable(); //make the table
        table.setModel(model);
        table.setAutoResizeMode(JTable.AUTO_RESIZE_ALL_COLUMNS);
        table.setFillsViewportHeight(true);
        JScrollPane scroll = new JScrollPane(table);
        try{
            Class.forName("com.mysql.jdbc.Driver");
            Connection conn = DriverManager.getConnection(url, username, password);

        }catch(Exception e){
            JOptionPane.showMessageDialog(null, e.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
        }
    panell.add(scroll,BorderLayout.CENTER);
    panel4 = new JPanel();
    panel4.setLayout(new FlowLayout());
    rb_siswa = new JRadioButton("Siswa");
    rb_dosen = new JRadioButton("Dosen");
    ButtonGroup bg = new ButtonGroup();
    bg.add(rb_siswa);
    bg.add(rb_dosen);
    rb_siswa.setSelected(true); //i set RadioButton siswa default
    panel4.add(rb_siswa);
    panel4.add(rb_dosen);
    panell.add(panel4,BorderLayout.NORTH);
    if(rb_siswa.isSelected()){ //the first if
        String[] columnNames= {"NIM", "ID_Jurusan", "ID_Kelas", "Name", "Tanggal_Lahir", "Gender", "Semester", "Alamat", "email", "nohp"};
        model.setColumnIdentifiers(columnNames);
        try{
        sql = "select * from siswa";
            PreparedStatement ps = conn.prepareStatement(sql);
            ResultSet rs = ps.executeQuery();
            while(rs.next()){
                NIM = rs.getString("NIM");
                IDJurusan = rs.getString("id_jurusan");
                IDKelas = rs.getString("id_kelas");
                Name = rs.getString("Nama");
                TL = rs.getString("TanggalLahir");
                gender = rs.getString("JenisKelamin");
                Semester = rs.getString("Semester");
                alamat = rs.getString("Alamat");
                email = rs.getString("e-mail");
                nohp = rs.getString("nohp");
                model.addRow(new Object[]{NIM, IDJurusan, IDKelas, Name, TL, gender, Semester, alamat, email, nohp});
            }
        }catch(Exception aae){
            JOptionPane.showMessageDialog(null, aae.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
        }
    }
    else if(rb_dosen.isSelected()){ // the second if
        String[] columnNames= {"ID_Dosen", "Name", "Gender", "Alamat", "email", "nohp"};
        model.setColumnIdentifiers(columnNames);
        try{
            sql = "select * from siswa";
            PreparedStatement ps = conn.prepareStatement(sql);
            ResultSet rs = ps.executeQuery();
            while(rs.next()){
                IDDosen = rs.getString("IDDosen");
                Name = rs.getString("Nama");
                gender = rs.getString("JenisKelamin");
                alamat = rs.getString("Alamat");
                email = rs.getString("email");
                nohp = rs.getString("nohp");
                model.addRow(new Object[]{IDDosen, Name, gender, alamat, email, nohp});
            }
        }catch(Exception aae){
    }
    }

如果我选择单选按钮，我想改变表格。我需要做一个按钮吗？

this is how the table looks like, hope can help you imagine

Answer 1

我对 Swing 知之甚少（最后一次使用它是在我上学的时候），但您似乎需要在单选按钮中添加一个 listener。

这里解释一下这个概念：http://www.java2s.com/Tutorial/Java/0240__Swing/ListeningtoJRadioButtonEventswithaChangeListener.htm

基本上你会想像这样创建一个更改监听器：

ChangeListener changeListener = new ChangeListener() {
  public void stateChanged(ChangeEvent changEvent) {
    AbstractButton aButton = (AbstractButton)changEvent.getSource();
    ButtonModel aModel = aButton.getModel();
    // Code to change table here
  }
};

然后您将获取更改侦听器并将其添加到您的按钮中，如下所示：

rb_siswa.addChangeListener(changeListener);
rb_dosen.addChangeListener(changeListener);

这应该可行。看起来无法将侦听器直接添加到 ButtonGroup 而不是按钮。这是我的第一个想法。您可以返回选择的 ButtonModel（如果我没看错的话），但 ButtonGroup 没有它自己的侦听器概念。

请看这里：https://docs.oracle.com/javase/7/docs/api/javax/swing/ButtonGroup.html

我希望这会有所帮助！

如果我有什么问题请告诉我，因为我已经很多年没有接触任何与挥杆相关的东西了！

Answer 2

您可以将ItemListener 添加到单选按钮。如果您只有两个单选按钮，请避免使用任何 Enumerator，直接使用如下内容：

JRadioButton radio1 = new JRadioButton("Hello");
JRadioButton radio2 = new JRadioButton("World");

ButtonGroup btnGroup = new ButtonGroup();

// add listeners to button
radio1.addActionListener(this);
radio2.addActionListener(this);

// add buttons to button group
btnGroup.add(radio1);
btnGroup.add(radio2);

.
.
.
// and implement the itemStateChanged() method as follows:
public void itemStateChanged(ItemEvent e){

       if(radio1.isSelected())
       {
            // create the default table model and then populate it to jtable and put the jtable into scroll bar (for student)
       }
       else {
            // same as above (for teacher).
       }

}