Help needed with passing data between classes, graph building application?

Question

Good afternoon please could you help me with a problem with my application, my head is starting to hurt?
I have run into some difficulties when trying to build an application that generates a linegraph?
Firstly i have a gui that the client will enter the data into a text area call jta; this data is tokenised and placed into a format the application can use, and past to a seperate class that draws the graph?
I think the problem lies with the way i am trying to put the data into co-ordinate form (x,y) as no line is being generated.
The following code is from the GUI:
+public void actionPerformed(ActionEvent e) {+
+// Takes data and provides program with CoOrdinates+
int[][]data = createData();
+// Set the data data to graph for display+
grph.showGrph(data);
+// Show the frame+
grphFrame.setVisible(true);
+}+
+/** set the data given to the application */+
+private int[][] createData() {+
+     //return data;+
+     String rawData = jta.getText();+
+     StringTokenizer tokens = new StringTokenizer(rawData);+
+     List list = new LinkedList();+
+     while (tokens.hasMoreElements()){+
+          String number = "";+
+          String token = tokens.nextToken();+
+          for (int i=0; i<token.length(); i++){+
+               if (Character.isDigit(token.charAt(i))){+
+                    number += token.substring(i, i+1);+
+               }+
+          }     +
+     }+
+     int [][]data = new int[list.size()/2][2];+
+     int index = -2;+
+     for (int i=0; i<data.length;i++){+
+               index += 2;+
+               data[0] = Integer.parseInt(+
+                         (list.get(index).toString()));+
+               data[i][1] = Integer.parseInt(+
+                         (list.get(index +1).toString()));+
+          }+
+     return data;+
The follwing is the coding for drawing the graph?
+public void showGrph(int[][] data)  {+
this.data = data;
repaint();
+}     +
+/** Paint the graph */+
+protected void paintComponent(Graphics g) {+
+//if (data == null)+
+     //return; // No display if data is null+
super.paintComponent(g);
+// x is the start position for the first point+
int x = 30;
int y = 30;
for (int i = 0; i < data.length; i+) {+
+g.drawLine(data[i][0],data[i][1],data[i+1][0],data[i+1][1]);+
+}+
+}+

Answer 1

Thanks for that tip!
package LineGraph;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
import java.util.List;
public class GUI extends JFrame
  implements ActionListener {
  private JTextArea Filejta;
  private JTextArea jta;
  private JButton jbtShowGrph = new JButton("Show Chromatogram");
  public JButton jbtExit = new JButton("Exit");
  public JButton jbtGetFile = new JButton("Search File");
  private Grph grph = new Grph();
  private JFrame grphFrame = new JFrame();   // Create a new frame to hold the Graph panel
  public GUI() {
     JScrollPane pane = new JScrollPane(Filejta = new JTextArea("Default file location: - "));
     pane.setPreferredSize(new Dimension(350, 20));
     Filejta.setWrapStyleWord(true);
     Filejta.setLineWrap(true);     
    // Store text area in a scroll pane 
    JScrollPane scrollPane = new JScrollPane(jta = new JTextArea("\n\n Type in file location and name and press 'Search File' button: - "
              + "\n\n\n Data contained in the file will be diplayed in this Scrollpane "));
    scrollPane.setPreferredSize(new Dimension(425, 300));
    jta.setWrapStyleWord(true);
    jta.setLineWrap(true);
    // Place scroll pane and button in the frame
    JPanel jpButtons = new JPanel();
    jpButtons.setLayout(new FlowLayout());
    jpButtons.add(jbtShowGrph);
    jpButtons.add(jbtExit);
    JPanel searchFile = new JPanel();
    searchFile.setLayout(new FlowLayout());
    searchFile.add(pane);
    searchFile.add(jbtGetFile);
    add (searchFile, BorderLayout.NORTH);
    add(scrollPane, BorderLayout.CENTER);
    add(jpButtons, BorderLayout.SOUTH);
    // Exit Program
    jbtExit.addActionListener(new ActionListener(){
    public void actionPerformed(ActionEvent e) {
         System.exit(0);
    // Read Files data contents
     jbtGetFile.addActionListener(new ActionListener(){
     public void actionPerformed( ActionEvent e) {
               String FileLoc = Filejta.getText();
               LocateFile clientsFile;
               clientsFile = new LocateFile(FileLoc);
                    if (FileLoc != null){
                         String filePath = clientsFile.getFilePath();
                         String filename = clientsFile.getFilename();
                         String DocumentType = clientsFile.getDocumentType();
     public String getFilecontents(){
          String fileString = "\t\tThe file contains the following data:";
     return fileString;
       // Register listener     // Create a new frame to hold the Graph panel
    jbtShowGrph.addActionListener(this);
    grphFrame.add(grph);
    grphFrame.pack();
    grphFrame.setTitle("Chromatogram showing data contained in file \\filename");
  /** Handle the button action */
  public void actionPerformed(ActionEvent e) {
    // Takes data and provides program with CoOrdinates
    int[][]data = createData();
    // Set the data data to graph for display
    grph.showGrph(data);
    // Show the frame
    grphFrame.setVisible(true);
  /** set the data given to the application */
  private int[][] createData() {
       String rawData = jta.getText();
       StringTokenizer tokens = new StringTokenizer(rawData);
       List list = new LinkedList();
       while (tokens.hasMoreElements()){
            String number = "";
            String token = tokens.nextToken();
            for (int i=0; i<token.length(); i++){
                 if (Character.isDigit(token.charAt(i))){
                      number += token.substring(i, i+1);
       int [][]data = new int[list.size()/2][2];
       int index = -2;
       for (int i=0; i<data.length;i++){
                 index += 2;
                 data[0] = Integer.parseInt(
                         (list.get(index).toString()));
               data[i][1] = Integer.parseInt(
                         (list.get(index +1).toString()));
     return data;
public static void main(String[] args) {
GUI frame = new GUI();
frame.setLocationRelativeTo(null); // Center the frame
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Clients Data Retrival GUI");
frame.pack();
frame.setVisible(true);
package LineGraph;
import javax.swing.*;
import java.awt.*;
public class Grph extends JPanel {
     private int[][] data;
/** Set the data and display Graph */
public void showGrph(int[][] data) {
this.data = data;
repaint();
/** Paint the graph */
protected void paintComponent(Graphics g) {
//if (data == null)
     //return; // No display if data is null
super.paintComponent(g);
//Find the panel size and bar width and interval dynamically
int width = getWidth();
int height = getHeight();
//int intervalw = (width - 40) / data.length;
//int intervalh = (height - 20) / data.length;
//int individualWidth = (int)(((width - 40) / 24) * 0.60);
////int individualHeight = (int)(((height - 40) / 24) * 0.60);
// Find the maximum data. The maximum data
//int maxdata = 0;
//for (int i = 0; i < data.length; i++) {
//if (maxdata < data[i][0])
//maxdata = data[i][1];
// x is the start position for the first point
int x = 30;
int y = 30;
//draw a vertical axis
g.drawLine(20, height - 45, 20, (height)* -1);
// Draw a horizontal base line4
g.drawLine(20, height - 45, width - 20, height - 45);
for (int i = 0; i < data.length; i++) {
//int Value = i;      
// Display a line
//g.drawLine(x, height - 45 - Value, individualWidth, height - 45);
g.drawLine(data[i][0],data[i][1],data[i+1][0],data[i+1][1]);
// Display a number under the x axis
g.drawString((int)(0 + i) + "", (x), height - 30);
// Display a number beside the y axis
g.drawString((int)(0 + i) + "", width - 1277, (y) + 900);
// Move x for displaying the next character
//x += (intervalw);
//y -= (intervalh);
/** Override getPreferredSize */
public Dimension getPreferredSize() {
return new Dimension(1200, 900);