Jtable doesn't refresh/update data
I have a problem with JTable/JScrollPane. My data table is not refreshing/updating. I am using DefultTableModel and according to the code everything is fine and I don't have any errors. Also I have a table with paging and that's why I am using action listeners and buttons "prev" and "next". I am passing from other function to function that is coded in class where is JTable. Problem is that I fill arrays which contains data for table but table won't update/refresh it. Here is my code. Thanks advance.
BIG EDIT Old code was removed. I added new codes that will help you guys/girls to understand problem that I have. Hope that this will help. Regards.
First here is class that show gui:
import javax.swing.*;
public class Glavni {
public static void main(String[] args) {
// TODO Auto-generated method stub
SwingUtilities.invokeLater(new Runnable() {
public void run() {
gui Scanner = new gui();
Scanner.setVisible(true);
}
});
}
}
Second here is class that pass String to gui class that contains jtable
public class passDatatoTable {
public void passData(){
String str1,str2,str3,str4;
gui SendStringsToGUI = new gui();
for (int i =0;i<=10;i++){
str1="Column 1 of row: "+i;
str2="Column 2 of row: "+i;
str3="Column 3 of row: "+i;
str4="Column 4 of row: "+i;
SendStringsToGUI.WriteMonitorData(str1, str2, str3, str4);
}
}
}
Next here is declaration of gui (contructor):
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class gui extends JFrame implements ActionListener {
private static final long serialVersionUID = 1L;
String[][] data = new String[100][4];
String[] columnNames = new String[]{
"IP", "PC_NAME", "ttl", "db"
};
DefaultTableModel model = new DefaultTableModel(data,columnNames);
JTable table = new JTable(model);
JScrollPane scrollPane = new JScrollPane(table);
int i=0;
public void WriteMonitorData (String IP, String PC_NAME, String ttl, String gw)
{
System.out.println(IP);//just for testing (check if data was passed)
model.setValueAt(IP, i, 0);
model.setValueAt(PC_NAME, i, 1);
model.setValueAt(ttl, i, 2);
model.setValueAt(gw, i, 3);
i++;
model.fireTableDataChanged();
table.repaint();
scrollPane.repaint();
}
gui(){
JButton addData= new JButton("Add Data");
JButton next = new JButton("next");
JButton prev = new JButton("prev");
addData.addActionListener(this);
next.addActionListener(this);
prev.addActionListener(this);
JPanel panel = new JPanel(new BorderLayout());
JPanel buttonPanel = new JPanel();
buttonPanel.add(addData);
buttonPanel.add(prev);
buttonPanel.add(next);
panel.add(buttonPanel, BorderLayout.SOUTH);
panel.add(table.getTableHeader(), BorderLayout.PAGE_START);
panel.add(scrollPane, BorderLayout.CENTER);
getContentPane().add(panel);
}
Here is actionListeners:
public void actionPerformed(ActionEvent e) {
if ("Add Data".equals(e.getActionCommand())){
passDatatoTable passSomeData = new passDatatoTable();
passSomeData.passData();
}
if ("next".equals(e.getActionCommand())) {
Rectangle rect = scrollPane.getVisibleRect();
JScrollBar bar = scrollPane.getVerticalScrollBar();
int blockIncr = scrollPane.getViewport().getViewRect().height;
bar.setValue(bar.getValue() + blockIncr);
scrollPane.scrollRectToVisible(rect);
}
if ("prev".equals(e.getActionCommand())) {
Rectangle rect = scrollPane.getVisibleRect();
JScrollBar bar = scrollPane.getVerticalScrollBar();
int blockIncr = scrollPane.getViewport().getViewRect().height;
bar.setValue(bar.getValue() - blockIncr);
scrollPane.scrollRectToVisible(rect);
}
}
Answer
Your first snippet shows this:
JTable table = new JTable(model);
but your gui() constructor shows:
JTable table = new JTable(data, columnNames);
You initiate the table twice. Once using the TableModel (JTable(TableModel tm)) the next using JTable(int rows,int cols) this is not good, initiate the JTable once in the constructor:
gui() {
DefaultTableModel model = new DefaultTableModel(data,columnNames);
JTable table = new JTable(model);
JScrollPane scrollPane = new JScrollPane(table);
JButton next = new JButton("next");
JButton prev = new JButton("prev");
next.addActionListener(this);
prev.addActionListener(this);
JPanel panel = new JPanel(new BorderLayout());
JPanel buttonPanel = new JPanel();
buttonPanel.add(prev);
buttonPanel.add(next);
panel.add(buttonPanel, BorderLayout.SOUTH);
panel.add(table.getTableHeader(), BorderLayout.PAGE_START);
panel.add(scrollPane, BorderLayout.CENTER);
getContentPane().add(panel);
}
UPDATE:
Here is an example that has a thread which will start 2.5 secinds after the UI is visible and change a value of the JTable:
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
public class Test extends JFrame {
public static void main(String[] args) throws Exception {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new Test().createAndShowUI();
}
});
}
private void createAndShowUI() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
initComponents(frame);
frame.pack();
frame.setVisible(true);
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(2500);
} catch (InterruptedException ex) {
Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
}
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
model.setValueAt("hello", 0, 0);
}
});
}
}).start();
}
static DefaultTableModel model;
private void initComponents(JFrame frame) {
String data[][] = {
{"1", "2", "3"},
{"4", "5", "6"},
{"7", "8", "9"},
{"10", "11", "12"}
};
String col[] = {"Col 1", "Col 2", "Col 3"};
model = new DefaultTableModel(data, col);
JTable table = new JTable(model);
frame.getContentPane().add(new JScrollPane(table));
}
}