trying to read a map into a combo box

[Larry Burden]

I am working on a project that requires me to read colors and Hex codes for the colors into a map from a text file. I have a TreeMap created and it stores and prints properly on the screen, but I can not figure out how to get it to send the data to a combo box. Here is my code thus far...

public class Project extends JFrame{
    
    JComboBox CBColor = new JComboBox(new String[]
    {"", "AQUA", "BLACK", "BLUE", "BROWN", "FUCHSIA", "GRAY",
    "GREEN", "INDIGO", "LIME", "MAROON", "NAVY", "ORANGE",
    "PINK", "PURPLE", "RED", "SIENNA", "TAN", "TEAL", "WHITE", "YELLOW"});
    JTextArea TAText = new JTextArea(5, 25);
    JButton BApply = new JButton("Apply");
    JButton BExit = new JButton("Exit");
  
    public Project() {
        JPanel SelectionPanel = new JPanel(new BorderLayout());
        SelectionPanel.add(CBColor, BorderLayout.NORTH);
        SelectionPanel.add(TAText, BorderLayout.CENTER);
        JPanel ApplyPanel = new JPanel(new FlowLayout(FlowLayout.CENTER, 10, 10));
        ApplyPanel.add(BApply);
        ApplyPanel.add(BExit);
        add(SelectionPanel, BorderLayout.NORTH);
        add(ApplyPanel, BorderLayout.SOUTH);
        BApply.addActionListener(new ButtonListener());
        BExit.addActionListener(new ExitButtonListener());
    }
      
    private class ButtonListener implements ActionListener {
            public void actionPerformed(ActionEvent e) {
                String BGColor = "";
                if (CBColor.getSelectedItem() == "AQUA")
                    BGColor = "#00FFFF";
                else if (CBColor.getSelectedItem() == "BLACK")
                    BGColor = "#000000";
                else if (CBColor.getSelectedItem() == "BLUE")
                    BGColor = "#0000FF";
                else if (CBColor.getSelectedItem() == "BROWN")
                    BGColor = "#A52A2A";
                else if (CBColor.getSelectedItem() == "FUCHSIA")
                    BGColor = "#FF00FF";
                else if (CBColor.getSelectedItem() == "GRAY")
                    BGColor = "#BEBEBE";
                else if (CBColor.getSelectedItem() == "GREEN")
                    BGColor = "#008000";
                else if (CBColor.getSelectedItem() == "INDIGO")
                    BGColor = "#4B0082";
                else if (CBColor.getSelectedItem() == "LIME")
                    BGColor = "#00FF00";
                else if (CBColor.getSelectedItem() == "MAROON")
                    BGColor = "#800000";
                else if (CBColor.getSelectedItem() == "NAVY")
                    BGColor = "#000080";
                else if (CBColor.getSelectedItem() == "ORANGE")
                    BGColor = "#FFA500";
                else if (CBColor.getSelectedItem() == "PINK")
                    BGColor = "#FFC0CB";
                else if (CBColor.getSelectedItem() == "PURPLE")
                    BGColor = "#800080";
                else if (CBColor.getSelectedItem() == "RED")
                    BGColor = "#FF0000";
                else if (CBColor.getSelectedItem() == "SIENNA")
                    BGColor = "#A0522D";
                else if (CBColor.getSelectedItem() == "TAN")
                    BGColor = "#D2B48C";
                else if (CBColor.getSelectedItem() == "TEAL")
                    BGColor = "#008080";
                else if (CBColor.getSelectedItem() == "WHITE")
                    BGColor = "#FFFFFF";
                else if (CBColor.getSelectedItem() == "YELLOW")
                    BGColor = "#FFFF00";
                TAText.setBackground(Color.decode(BGColor));
            }
    }
    
    private class ExitButtonListener implements ActionListener {
            public void actionPerformed(ActionEvent e) {
            System.exit(0);
            }
    }
    
    public static void main(String[] args) throws Exception {
                
        Map<String, String> ColorsHex = new TreeMap<String, String>();
 
        BufferedReader input = new BufferedReader(new FileReader("colors.txt"));
        String line = "";
        while ((line = input.readLine()) != null) {
            String parts[] = line.split(", ");
            ColorsHex.put(parts[0], parts[1]);
        }
        input.close();        
        System.out.println(ColorsHex);
        System.out.print(ColorsHex.keySet());
        System.out.print(ColorsHex.get("RED"));
        
      
        Project frame = new Project();
        frame.setTitle("Colors");
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
        
        
        
    }
   
   
}

This compiles and runs, but i am trying to get the combo box to read the values imported instead of entering them, and the listener to read the elements instead of entering them.

[Kemal Sokolovic]

Hello and welcome to the Ranch! Please read CarefullyChooseOneForum since this would be a topic for Swing forum.

Now, let's get to the point of the topic.
You should have your map as field inside your frame class. The code you have in your main method where you read colors.txt should be put as separate method, also inside your class (say, readColors(), or whatever name you come up with). Inside that method you would read your file as you did inside main, and put read values in your map. Afterwards, you can populate combo box with keys from your map, without initializing combo box with String array:

// Instead of your combo box initialization, put this:
JComboBox CBColor = new JComboBox();

// Once you read txt, populate combo box with
// values of your map
for(String key : ColorsHex.keySet())
{
    CBColor.addItem(key);
}

Now you can avoid all those if/else if you have in your ButtonListener:

public void actionPerformed(ActionEvent e)
{
    String BGColor = "";
    // BGColor will contain hex value based on the key which is actually
    // an item selected in your combo box
    BGColor = ColorsHex.get(CBColor.getSelectedItem().toString());
    // Apply selected color
    TAText.setBackground(Color.decode(BGColor));
}

Note just that if you want to have an empty string as one item in your combobox, you should map it to a default color (say white), otherwise you will get NullPointerException when user selects it, with the approach given above. Also, if you are using JDK 7 you can avoid multiple if/else-if since you can use a String as an expression in switch statement. You don't need it in this example, but keep that in mind in your future work.

At the end, I must notice that you don't really follow convention for naming variables.