How to make a cell in JTable a different colour?

Question

Hi, i've been playing with JTables with a custom CellRenderer, which I'm trying to make so that in the JTable, when two values down a column are found to be the same, the back ground colour changes to something same (hoping that there is a way to randomize the colour values) the code i have atm is
In the main program :
                    find.addActionListener(new ActionListener() {
                         public void actionPerformed(ActionEvent ae) {
                              datahome = cC.data;
                              TableColumnModel colModel = cC.jtable.getColumnModel();
                              TableColumn column = colModel.getColumn(0);
                              column.setCellRenderer(new RedCellRenderer(new int[] {1,2}));
in the cellrenderer:
package packageSolo;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.*;
import java.awt.*;
public class SetCellColour extends DefaultTableCellRenderer {
     private int arrVerifyColumns[] = null;
     public SetCellColour(int iTestColumns[]) {
          arrVerifyColumns = iTestColumns;
     public Component getTableCellRendererComponent(JTable table, Object value,
               boolean isSelected, boolean hasFocus, int row, int column) {
          this.setBackground(Color.RED); // All columns verified were empty - set
          // our background RED
          return this;
}any my problem is that this cellrenderer will change the column and not just the cell, i've tried to pass where the cell is (the x and y of the cell) to the cellrenderer, but there is no way for me to interpret this value in cellrenderer and set that cell to that colour i'm not sure if there is a cell model instead of column model and be able to pass that onto the cellrenderer

Answer 1

ell after several tries, i have determined that it may be something wrong with that my jtable is part of a JPanel, that is attached to a container with scroll pane that is then added to a JFrame's center... and somewhere here it freezes the display...
my code for the actual JFrame:
package packageSolo;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class ConflictCheckerGUIIntialization extends JFrame {
      * debugger
      * @param x
      *            takes in an int and prints a debug line when enabled to the
      *            console
     private void debug(int x) {
          // System.out.print("Flag: "+ x);
     private static int flag1 = 0;
     private static int flag2 = 0;
     private static int flag3 = 0;
     private static int flag4 = 0;
     private static int flag5 = 0;
     private static int flag6 = 0;
     private static int flag7 = 0;
     private static int flag8 = 0;
     private static int flag9 = 0;
     private Object[][] datahome;
     private JButton cConflict = new JButton("Check Conflict");
     private JButton find = new JButton("Find");
     private JButton quit = new JButton("Exit");
     // private JButton northavg = new JButton("North's Average");
     // private JButton eastavg = new JButton("East's Average");
     // private JButton largest = new JButton("Largest Percepitation");
     // private JButton totalPercepitation = new JButton("Total Percepitation");
     private ConflictCheckerGUI cC = new ConflictCheckerGUI();
     private JFrame jf = new JFrame();
     private JFrame jf1 = new JFrame();
     // Get the size of the default screen
     private static Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
     private int screensizex = (int) (dim.width * 0.8);
     private int screensizey = (int) (dim.height * 0.75);
     private static int gcsizex = (int) (dim.width * 0.625);
     private static int gcsizey = (int) (dim.height * 0.1953125);
     private static GUIConsole gc = new GUIConsole("Output", gcsizex, gcsizey);
     public ConflictCheckerGUIIntialization() {
          boolean RunOnce = false;
          while (RunOnce == false) {
               if (cC.finished == true) {
                    System.out.println("he");
                    Container c1 = jf.getContentPane();
                    c1.setLayout(new FlowLayout());
                    Container c = this.getContentPane();
                    Container c2 = jf1.getContentPane();
                    JPanel jp = new JPanel();
                    jp.add(cC);
                    cConflict.addActionListener(new ActionListener() {
                         public void actionPerformed(ActionEvent ae) {
                              datahome = cC.data;
                              // System.out.print(datahome
                              // [0][0].toString().compareTo(datahome
                              // [1][0].toString()));
                              // System.out.print(datahome
                              // [0][0].toString().equals(datahome
                              // [1][0].toString()));
                              for (int conflictCounter2 = 1; conflictCounter2 < 3; conflictCounter2++) {
                                   int conflictCounter4 = 0;
                                   for (int conflictCounter1 = 0; conflictCounter1 <= cC.Classroomint; conflictCounter1++) {
                                        conflictCounter4++;
                                        for (int conflictCounter3 = 1; conflictCounter3 <= (cC.Classroomint - conflictCounter4); conflictCounter3++) {
                                             if (datahome[conflictCounter2][conflictCounter1]
                                                       .toString()
                                                       .equals(
                                                                 datahome[conflictCounter2][conflictCounter1
                                                                           + conflictCounter3]
                                                                           .toString())) {
                                                  System.out.println("error at "
                                                            + conflictCounter2 + " "
                                                            + conflictCounter1);
                               * for (int counter1 = 0; counter1 < pg.monthint;
                               * counter1++) { for (int counter2 = 0; counter2 < 5;
                               * counter2++) {
                               * System.out.print(datahome[counter1][counter2] +
                               * "\t"); } System.out.println(); }
                    quit.addActionListener(new ActionListener() {
                         public void actionPerformed(ActionEvent ae) {
                              try {
                                   System.exit(0);
                              } catch (SecurityException ea) {
                                   System.out.println("Cannot exit");
                    find.addActionListener(new ActionListener() {
                         public void actionPerformed(ActionEvent ae) {
                              datahome = cC.data;
                              Object value = null;
                              cC.jtable.getCellRenderer(0, 0)
                                        .getTableCellRendererComponent(cC.jtable,
                                                  value, false, true, 0, 0).setFont(new Font(
                                                  "Serif", Font.BOLD, 14));
                              System.out.println(cC.data[0][0].toString());
                              // .setFont(new Font("serif", Font.BOLD, 12));
                    gc
                              .println("There is a known bug with this program that if you enter any information in the table,");
                    gc
                              .println("then not confirming it by not going to another cell, then the data you've entered it not valid and not considered to be input,");
                    gc
                              .println("this will be fixed in future revisions if possible");
                    gc.show();
                    gc.setLocation(0, screensizey);
                                *bold*
                               *bold* c2.add(jp, "Center");
                    *bold*c2.add(new JScrollPane(jp,
                              *bold*ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,
                              *bold*ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED),
                              *bold*"Center");
                    c1.setLayout(new GridLayout(2, 5));
                    c1.add(cConflict);
                    c1.add(find);
                    c1.add(quit);
                    c1.setVisible(true);
                    c2.setVisible(true);
                    c.add(c1, "South");
                    c.add(c2, "Center");
                    c.setVisible(true);
                    this.pack();
                    this.setTitle("Lancer's Class Conflict Checker");
                    this.setDefaultCloseOperation(EXIT_ON_CLOSE);
                    this.setSize(screensizex, screensizey);
                    RunOnce = true;
                    // ! this.pack(); //this tries to set the size of the thing to a
                    // perferred size, and if used will not alow the dynamic sizing
                    // of
                    // the
                    // main JTable window based on the user's screensize
     public static void main(String[] args) {
          ConflictCheckerGUIIntialization x = new ConflictCheckerGUIIntialization();
          x.setVisible(true);
}here, the JPanel with the jtable is added to c2 and c2 is added to c and c's parent is the JFrame of this whole class
and the code for the jtable JPanel is:
package packageSolo;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileNotFoundException;
import javax.swing.*;
import javax.swing.table.*;
public class ConflictCheckerGUI extends JPanel {
     private void debug(int x) {
          // System.out.println(x);
     protected static boolean finished = false;
     protected static DefaultTableModel[][] data;
     protected static int Classroomint = 0;
     protected static JTable jtable;
     protected static String[] columnNames = { "Classroom", "Period One",
               "Period Two", "Period Three", "Period Four" };
     protected static int GoAheadFlag = 0;
     SetCellColour renderer;
     public ConflictCheckerGUI() {
          // super(new GridLayout(1, 0));
          JFrame Choose = new JFrame();
          Choose.setDefaultCloseOperation(Choose.EXIT_ON_CLOSE);
          JButton ImportFromFile = new JButton("Impoort From File");
          JButton New = new JButton("New Planner");
          ImportFromFile.addActionListener(new ActionListener() {
               public void actionPerformed(ActionEvent ae) {
                    String[] North;
                    String[] East;
                    String[] South;
                    String[] West;
                    String[] Month;
                    // JFileChooser fc = new JFileChooser();
                    // fc.show();
                    // int returnVal = fc.showOpenDialog(fc);
                    // File file = null;
                    // if (returnVal == JFileChooser.APPROVE_OPTION) {
                    // file = fc.getSelectedFile();
                    java.util.Scanner parse = null;
                    File file = new File(
                              "E://Documents and Settings//TheHolyLancer//My Documents//java - old//Eclipse workspace//Precipitation//packageSolo//datasave.txt");
                    try {
                         parse = new java.util.Scanner(file);
                    } catch (FileNotFoundException e) {
                         // TODO Auto-generated catch block
                         e.printStackTrace();
                    Classroomint = Integer.parseInt(parse.next());
                    North = new String[Classroomint];
                    East = new String[Classroomint];
                    South = new String[Classroomint];
                    West = new String[Classroomint];
                    Month = new String[Classroomint];
                    for (int counter1 = 0; counter1 < Classroomint; counter1++) {
                         Month[counter1] = "n/a";
                    for (int counter2 = 0; counter2 < Classroomint; counter2++) {
                         North[counter2] = "n/a";
                         East[counter2] = "n/a";
                         South[counter2] = "n/a";
                         West[counter2] = "n/a";
                    data = new DefaultTableModel[Classroomint][5];
                    jtable = new JTable(new DefaultTableModel(Classroomint,5));//columnnames
                    jtable.setPreferredScrollableViewportSize(new Dimension(800,
                              600));
                    finished = true;
          New.addActionListener(new ActionListener() {
               public void actionPerformed(ActionEvent ae) {
                    String input;
                    String[] North;
                    String[] East;
                    String[] South;
                    String[] West;
                    String[] Month;
                    int flag2 = 0;
                    int flag4 = 0;
                    int flag5 = 0;
                    int flag8 = 0;
                    input = JOptionPane
                              .showInputDialog("How many classromms are there?");
                     * see if the user wantes to quit at this point
                    if (input == null) {
                         debug(4);
                         int exitint = 0;
                         exitint = JOptionPane.showConfirmDialog(null,
                                   "Do you want to exit?", "Exit?",
                                   JOptionPane.OK_CANCEL_OPTION);
                         if (exitint == 0) {
                              try {
                                   System.exit(1);
                              } catch (SecurityException eb) {
                                   System.out.println("exit");
                    while (flag4 == 0) {
                          * this while loop with flag2 is for checking if the thing
                          * is of int class
                         while (flag2 == 0) {
                               * try to get a integer, check for a bad input class
                              try {
                                    * parse, and if success set flag2 to 1 and break
                                    * out this while loop
                                   Classroomint = Integer.parseInt(input);
                                   flag2 = 1;
                                   debug(2);
                              } catch (NumberFormatException ec) {
                                   debug(3);
                                    * ops user input was not a integer class
                                   JOptionPane.showMessageDialog(null,
                                             "Enter a positive integer only",
                                             "Number Format is Wrong",
                                             JOptionPane.ERROR_MESSAGE);
                                   input = JOptionPane
                                             .showInputDialog("How many months are there?");
                                    * see if the user wantes to quit at this point
                                   if (input == null) {
                                        debug(4);
                                        int exitint = 0;
                                        exitint = JOptionPane.showConfirmDialog(null,
                                                  "Do you want to exit?", "Exit?",
                                                  JOptionPane.OK_CANCEL_OPTION);
                                        if (exitint == 0) {
                                             try {
                                                  System.exit(1);
                                             } catch (SecurityException eb) {
                                                  System.out.println("exit");
                          * this while loop sees if the integer is smaller than 0 so
                          * the array cannot be a real one
                         while (flag5 == 0) {
                              // numamountint = Integer.parseInt(numamount);
                              if (Classroomint < 0) {
                                   debug(5);
                                   JOptionPane.showMessageDialog(null,
                                             "Enter a positive integer",
                                             "Number Format/Size is Wrong",
                                             JOptionPane.ERROR_MESSAGE);
                                   input = JOptionPane
                                             .showInputDialog("How many months are there?");
                                   if (input == null) {
                                        int exitint = 0;
                                        exitint = JOptionPane.showConfirmDialog(null,
                                                  "Do you want to exit?", "Exit?",
                                                  JOptionPane.OK_CANCEL_OPTION);
                                        if (exitint == 0) {
                                             try {
                                                  System.exit(1);
                                             } catch (SecurityException eb) {
                                                  System.out.println("exit");
                                    * this while loop check for number format again
                                   while (flag8 == 0) {
                                        try {
                                             debug(6);
                                             Classroomint = Integer.parseInt(input);
                                             flag8 = 1;
                                        } catch (NumberFormatException ec) {
                                             debug(7);
                                             JOptionPane.showMessageDialog(null,
                                                       "Enter a positive integer only",
                                                       "Number Format is Wrong",
                                                       JOptionPane.ERROR_MESSAGE);
                                             input = JOptionPane
                                                       .showInputDialog("How many months are there?");
                                             if (input == null) {
                                                  int exitint = 0;
                                                  exitint = JOptionPane
                                                            .showConfirmDialog(
                                                                      null,
                                                                      "Do you want to exit?",
                                                                      "Exit?",
                                                                      JOptionPane.OK_CANCEL_OPTION);
                                                  if (exitint == 0) {
                                                       try {
                                                            System.exit(1);
                                                       } catch (SecurityException eb) {
                                                            System.out.println("exit");
                              } else {
                                    * here the input is greater than 0 so it sets flag5
                                    * and 4 then break out of the while loops
                                   debug(8);
                                   flag5 = 1;
                                   flag4 = 1;
                    North = new String[Classroomint];
                    East = new String[Classroomint];
                    South = new String[Classroomint];
                    West = new String[Classroomint];
                    Month = new String[Classroomint];
                    for (int counter1 = 0; counter1 < Classroomint; counter1++) {
                         Month[counter1] = "n/a";
                    for (int counter2 = 0; counter2 < Classroomint; counter2++) {
                         North[counter2] = "n/a";
                         East[counter2] = "n/a";
                         South[counter2] = "n/a";
                         West[counter2] = "n/a";
                    DefaultTableModel tableModel = new DefaultTableModel(Classroomint, 0);
                    tableModel.addColumn("Classroom");
                    tableModel.addColumn("Period One");
                    tableModel.addColumn("Period Two");
                    tableModel.addColumn("Period Three");
                    tableModel.addColumn("Period Four");
                    /*protected static String[] columnNames = { "Classroom", "Period One",
                         "Period Two", "Period Three", "Period Four" };*/
                    // /jtable = new JTable(data, columnNames);
                    jtable = new JTable(tableModel) {
                         private static final long serialVersionUID = 1L;
                         public TableCellRenderer getCellRenderer(int row, int col) {
                              return renderer;
                    jtable.setRowSelectionAllowed(true);
                    jtable.setPreferredScrollableViewportSize(new Dimension(800,
                              600));
                    finished = true;
          Container ButtonHolder = new Container();
          ButtonHolder.setLayout(new GridLayout(1, 2));
          ButtonHolder.add(New);
          ButtonHolder.add(ImportFromFile);
          Choose.add(ButtonHolder);
          Choose.setSize(200, 300);
          Choose.setVisible(true);
          boolean RunOnce = false;
          while (RunOnce == false) {
               if (finished == true) {
                    //JScrollPane scrollPane = new JScrollPane(jtable);
                    this.add( jtable, BorderLayout.CENTER );
                    Choose.setEnabled(false);
                    RunOnce = true;
}but upon start, and select start new table, the windows come up, but on where the large JFrame is and where the jtable is, nothing appears, and it acts like a screen cap and the thing just stucks like what is on the background of the computer... i think in all this linking i may have screwed something up, and the examples given were not designed for JPanels, but rather for JFrames... maybe i could implement all this into one class, since the buttons for choosing from load from file and all that can be in the first file as another JFrame, that is first visible, then when user chose one, something becomes visible, or something
but anyone knows how to fix all this?