Hi I'm new in Java and I have a application that reads multiple text files and displays them in a Jtable.So can you please tell me how can I make a bar graph that will display the data from my table.I tried using the code from your page (http://www.roseindia.net/chartgraphs/bar-chart.shtml) but I couldn't make it work. Thanks in advance.

Here is my code

package table2;

import java.io.*; import java.awt.*; import java.util.*; import javax.swing.*; import java.awt.event.*; import javax.swing.table.*; import java.awt.color.*; import org.jfree.chart.ChartFactory; import org.jfree.chart.ChartFrame; import org.jfree.chart.JFreeChart; import org.jfree.chart.plot.CategoryPlot; import org.jfree.chart.plot.PlotOrientation; import org.jfree.data.category.DefaultCategoryDataset;

public class InsertFileDataToJTable extends AbstractTableModel {

Vector data;
Vector columns;

public InsertFileDataToJTable() {
    String line;
    data = new Vector();
    columns = new Vector();
    columns.addElement("ID");
    columns.addElement("RSSI");

    String path = "C:/Users/Nikica/Desktop/text files";

    String files;
    File folder = new File(path);
    File[] listOfFiles = folder.listFiles();

    for (int y = 0; y < listOfFiles.length; y++) {
        if (listOfFiles[y].isFile()) {
            files = listOfFiles[y].getName();
            if (files.endsWith(".txt") || files.endsWith(".TXT")) {

                System.out.println(files);
                //    TreeMap<String, Integer> frequencyMap = new TreeMap<String, Integer>(); 


                File textFile = new File(folder.getAbsolutePath() + File.separator + files);
                try {

                    FileInputStream fis = new FileInputStream(textFile);
                    // DataInputStream in = new DataInputStream(fis);
                    BufferedReader br = new BufferedReader(new InputStreamReader(fis));


                    int i = 0;
                    while ((line = br.readLine()) != null) {
                        if (line.startsWith("17/10/2012 10:00:06.67 [RX] - E usbR<LF>") || line.startsWith("E qEnd<LF>") || line.startsWith("00<LF>")) {
                            continue;
                        }
                        String ID = line.substring(0, 12);
                        String RSSI = line.substring(13, 15);
                        data.addElement(ID);
                        data.addElement(RSSI);

                    }

                    br.close();

                    /*
                     * FileInputStream fis = new FileInputStream("ard.txt");
                     * BufferedReader br = new BufferedReader(new
                     * InputStreamReader(fis)); StringTokenizer st1 = new
                     * StringTokenizer(br.readLine(), "-"); while
                     * (st1.hasMoreTokens()) {
                     * columns.addElement(st1.nextToken()); } while ((line =
                     * br.readLine()) != null) { StringTokenizer st2 = new
                     * StringTokenizer(line, "-"); while
                     * (st2.hasMoreTokens()) {
                     * data.addElement(st2.nextToken()); } } br.close();
                     */
                } catch (Exception e) {
                    e.printStackTrace();
                }

            }
        }
    }
}

public int getRowCount() {
    return data.size() / getColumnCount();
}

public int getColumnCount() {
    return columns.size();
}

public Object getValueAt(int rowIndex, int columnIndex) {
    return (String) data.elementAt((rowIndex * getColumnCount())
            + columnIndex);
}

public static void main(String s[]) {
    InsertFileDataToJTable model = new InsertFileDataToJTable();
    JTable table = new JTable();
    table.setAutoCreateRowSorter(true);
    JTableHeader header = table.getTableHeader();
    table.setModel(model);
    table.getColumnModel().getColumn(0).setHeaderValue("ID");
    table.getColumnModel().getColumn(1).setHeaderValue("RSSI");
    table.getTableHeader().resizeAndRepaint();

    JScrollPane scrollpane = new JScrollPane(table);
    JPanel panel = new JPanel();
    panel.add(scrollpane);
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.add(panel, "Center");
    frame.pack();
    frame.setVisible(true);

}

}