Populating a combobox from a text file.

[Mike.]

I've tried googling for help but I never got it working.
I'm bad in java and everyother programming language so I don't really have a clue what I should do.
I just try something and if it doesn't work I'll try something else.

This time I'm did not succeed with that stragedy :P

I'm coding a small java swing program which should help me with bookkeeping..
I want it to populate a combobox from a text file, so every line is one option to choose from.
The lines will be short, max 15 characters or so.

So, heres my code at the moment:

import java.awt.GridLayout;
import java.awt.List;
import java.awt.event.ActionEvent;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;

import javax.swing.*;

public class Engine extends JPanel {

	
    /**
	 * 
	 */
	private static final long serialVersionUID = -1828230033027140410L;





	public Engine() {
        super(new GridLayout(10,3));  //2 rows, 1 column
        JLabel label1, label2, label3, label4, label5, label6, label7, filler1, filler2, filler3, filler4, filler5, filler6, filler7,
        filler8, filler9;
        
        JComboBox answer1, answer2, answer3, answer5, answer6, answer7;
        JTextField answer4;
        JButton edit1, edit2, edit3, edit5, edit6, button1, button2;
        
 
        //Create the labels:
        label1 = new JLabel("Item type:");
        label2 = new JLabel("Item status:");
        label3 = new JLabel("Item name:");
        label4 = new JLabel("Item attributes:");
        label5 = new JLabel("Account name:");
        label6 = new JLabel("Character position:");
        label7 = new JLabel("Choose file to open:");
 
        //Create the "answers":
        answer1 = new JComboBox(itemtype);
        answer2 = new JComboBox(itemstatus);
        answer3 = new JComboBox(itemname);
        answer4 = new JTextField();
        answer5 = new JComboBox();
        answer6 = new JComboBox();
        answer7 = new JComboBox();
        
        //Create the edit buttons:
        edit1 = new JButton("Edit");
        edit2 = new JButton("Edit");
        edit3 = new JButton("Edit");
        edit5 = new JButton("Edit");
        edit6 = new JButton("Edit");
        
        //Create the fillers:
        filler1 = new JLabel("");
        filler2 = new JLabel("");
        filler3 = new JLabel("");
        filler4 = new JLabel("");
        filler5 = new JLabel("");
        filler6 = new JLabel("");
        filler7 = new JLabel("");
        filler8 = new JLabel("");
        filler9 = new JLabel("");
        
        //Create the other buttons:
        button1 = new JButton("Add item");
        button2 = new JButton("Open");
 
        //Add the components.
        add(label1);
        add(answer1);
        add(edit1);
        
        add(label2);
        add(answer2); 
        add(edit2);
        
        add(label3);
        add(answer3);
        add(edit3);
        
        add(label4);
        add(answer4);
        add(filler1);
        
        add(label5);
        add(answer5);
        add(edit5);
        
        add(label6);
        add(answer6);
        add(edit6);
        
        add(filler2);
        add(filler3);
        add(filler4);
        
        add(filler5);
        add(button1);
        add(filler6);
        
        add(filler7);
        add(filler8);
        add(filler9);
        
        add(label7);
        add(answer7);
        add(button2);
        
        //Create the listeners:
        
        button1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                button1ActionPerformed(evt);
            }
        });
	}
	
	
	
    protected void button1ActionPerformed(ActionEvent evt) {

		
	}
    
    public String itemnames() {
    	BufferedReader input = new BufferedReader(new FileReader("itemnames.txt"));
    	ArrayList<String> itemnames = new ArrayList<String>();
    	try {
    	  String line = null;
    	  while (( line = input.readLine()) != null){
    	    itemnames.add(line);
    	  }
    	}

    	catch (FileNotFoundException e) {
    	    System.err.println("Error, file " + "itemnames.txt" + " didn't exist.");
    	}
    	finally {
    	    input.close();
    	}

    }
    



	/**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void engineGUI() {
        // Create and set up the window.
        JFrame mainframe = new JFrame("Mule Handler PRO - main window");
        mainframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        mainframe.add(new Engine());
        mainframe.pack();
        mainframe.setSize(400,200); // make frame 400x200
        mainframe.setResizable(false);
        mainframe.setVisible(true);
    }
     
    
    
    
    
    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                engineGUI();
            }
        });
    }
    
    
    String[] itemtype = {"Amulet", "Armor", "Belt", "Boots", "Charm", "Gloves", "Helmet", "Jewel", "Ring", "Rune", "Shield" ,"Weapon"};
    String[] itemstatus = {"Non-ethereal", "Ethereal"};
    String[] itemname = itemnames.toArray(new String[]{});

}

So as you see I'm trying to read the text file with this:

    public String itemnames() {
    	BufferedReader input = new BufferedReader(new FileReader("itemnames.txt"));
    	ArrayList<String> itemnames = new ArrayList<String>();
    	try {
    	  String line = null;
    	  while (( line = input.readLine()) != null){
    	    itemnames.add(line);
    	  }
    	}

    	catch (FileNotFoundException e) {
    	    System.err.println("Error, file " + "itemnames.txt" + " didn't exist.");
    	}
    	finally {
    	    input.close();
    	}

    }

Any solutions or suggestions?

[DarrylBurke]

Any solutions or suggestions?

To get better help sooner, post a SSCCE (Short, Self Contained, Compilable and Executable) example that demonstrates the problem. Your question is about populating a JComboBox, so all those buttons and labels and an empty actionPerformed(...) method only create clutter.

Do you know how to read a text file one line at a time?
Do you know how to add a String as an item in a JComboBox?
Have you gone through the Oracle tutorials on the two subjects?

db