Display RGB values

Question

Hello I am trying to display the RGB values of a color a user has chosen from a Hash Table, but I am confused and stuck on the syntax of using getRGB() method to display in a JTextArea method setText(). Just looking for a clue here is the line of code I am having trouble with:
displayRGB.setText((String)colorTable.get(input));
Thanks.
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import javax.swing.*;
public class ColorHashTable extends JFrame
  private JLabel inputLabel;
  private JTextField inputArea;
  private JButton goButton;
  private JTextArea displayRGB;
  private Hashtable colorTable;
  private JPanel southPanel;
  public ColorHashTable()
    super("Colors Using a Hash Table");
    //set up GUI
    Container container = getContentPane();
    container.setLayout(new BorderLayout());
    //set up North of window's Border Layout
    JPanel northPanel = new JPanel();
    inputLabel = new JLabel();
    northPanel.add(new JLabel ("Enter color number(1-10)"));
    inputArea = new JTextField(2);
    goButton = new JButton("Go");
    northPanel.add(inputArea);
    northPanel.add(goButton);
    //set up South of window's Border Layout
    southPanel = new JPanel();
    displayRGB = new JTextArea(2, 20);
    southPanel.add(displayRGB);
    container.add(northPanel, BorderLayout.NORTH);
    container.add(southPanel, BorderLayout.CENTER);
    //create Hash Table
    colorTable = new Hashtable();
    //add keys and color items to Hash Table
    colorTable.put("1",Color.BLUE);
    colorTable.put("2",Color.BLACK);
    colorTable.put("3",Color.CYAN);
    colorTable.put("4",Color.DARK_GRAY);
    colorTable.put("5",Color.GREEN);
    colorTable.put("6",Color.PINK);
    colorTable.put("7",Color.MAGENTA);
    colorTable.put("8",Color.ORANGE);
    colorTable.put("9",Color.YELLOW);
    colorTable.put("10",Color.RED);
    //actionListner
    goButton.addActionListener(
    new ActionListener()
      public void actionPerformed(ActionEvent event)
        if (event.getSource().equals(goButton))
          colorTheSouthPanelBackground();
    setSize(550, 130);
    setVisible(true);
  }//end constructor
  private void colorTheSouthPanelBackground()
    String input = inputArea.getText();
    southPanel.setBackground((Color)colorTable.get(input));
    displayRGB.setText((String)colorTable.get(input));
  public static void main(String[] args)
    ColorHashTable application = new ColorHashTable();
    application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

Answer 1

Your HashTable's values are Color objects not String objects. You can use getRGB() to get the actual RGB value or getRed(), getGreen(), getBlue() to get the individual values. How do you want format it? You'll have to convert it to a hex string (use Integer.toHexString()) if you want to show the common #RRGGBB format (i.e. #A35FDC). It might be a good practice to learn how you can separate out the red, green, and blue yourself using bitwise operators and a shift too.