Hey guys, I'm trying to build an Employee system GUI, and right now i'm trying to create a JComboBox to display all of the Employees, but whenever I compile, I get the following errors..

nathan@ubuntu:~/Desktop/Employee GUI [Java]$ javac RectangleProgram.java
RectangleProgram.java:42: cannot find symbol
symbol  : constructor JComboBox(java.lang.String)
location: class javax.swing.JComboBox
		employeesCB = new JComboBox(getEmployees());
		              ^
1 error

my code is as below.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

import java.io.*;
import java.util.*;

public class RectangleProgram extends JFrame {
	private static final int WIDTH = 230;
	private static final int HEIGHT = 220;

	private JLabel idL, nameL, titleL, hireyearL, salaryL;
	private JTextField idTF, nameTF, hireyearTF, salaryTF;
	private JComboBox titleCB, employeesCB;
	private JButton addToFile, exitB, clearB;
	private JMenuItem close, view;

	private ExitButtonHandler ebHandler;
	private AddToFileHandler atfHandler;
	private ClearButtonHandler cbHandler;
	//private ShowEmployeesHandler seHandler;

	String[] rank = {"", "Trainee", "Crew", "Senior", "Manager", "Owner"};
	
	public RectangleProgram() {
	   super("Welcome");
		Container pane = getContentPane();

		idL = new JLabel("ID: ", SwingConstants.RIGHT);
		nameL = new JLabel("Name: ", SwingConstants.RIGHT);
		titleL = new JLabel("Title: ", SwingConstants.RIGHT);
		hireyearL = new JLabel("Hire Year: ", SwingConstants.RIGHT);
		salaryL = new JLabel("Salary: ", SwingConstants.RIGHT);

		idTF = new JTextField(4);
		  idTF.setEditable(false);
		  idTF.setText(getId());
		nameTF = new JTextField(25);
		titleCB = new JComboBox(rank);
		hireyearTF = new JTextField(4);
		salaryTF = new JTextField(12);
		employeesCB = new JComboBox(getEmployees());

		JMenuBar mb = new JMenuBar();
	        JMenu me = new JMenu("Menu"); 
		JMenu se = new JMenu("Settings");
        	close = new JMenuItem("Close");
		view = new JMenuItem("View Employees");
		   /*seHandler = new ShowEmployeesHandler();
		   view.addActionListener(seHandler);*/
		mb.add(me);
		mb.add(se);
		me.add(view);
		me.add(close);
		setJMenuBar(mb);

		addToFile = new JButton("Add To File");
		atfHandler = new AddToFileHandler();
		addToFile.addActionListener(atfHandler);
		exitB = new JButton("Exit");
		ebHandler = new ExitButtonHandler();
		exitB.addActionListener(ebHandler);
		clearB = new JButton("Clear");
		cbHandler = new ClearButtonHandler();
		clearB.addActionListener(cbHandler);

		pane.setLayout(new GridLayout(7,2,1,1));

		pane.add(idL);
		pane.add(idTF);
		pane.add(nameL);
		pane.add(nameTF);
		pane.add(titleL);
		pane.add(titleCB);
		pane.add(hireyearL);
		pane.add(hireyearTF);
		pane.add(salaryL);
		pane.add(salaryTF);
		pane.add(addToFile);
		pane.add(exitB);
		pane.add(employeesCB);

		setSize(WIDTH, HEIGHT);
		setVisible(true);
		setDefaultCloseOperation(EXIT_ON_CLOSE);
	}

	public String getId() {
  	  String fname, leId = "";
  	  int counter = 0, ID = 0, employee = 0;

	ArrayList<Integer> Id = new ArrayList<Integer>();
	try {
	Scanner s = new Scanner(new File("rectangle.txt"));
		while(s.hasNext()) {
  			int id = s.nextInt();
		        String name = s.next();
			String lname = s.next();
  			String title = s.next();
  			int hireYear = s.nextInt();
  			double salary = s.nextDouble();
				fname = name + " " + lname;

		if(id > ID) {
			ID = id;
		}
		    counter++;
		}
	} catch(FileNotFoundException exc) {
            System.out.println("There was a problem:" + exc);
        }
		leId = Integer.toString(ID+1);
	return leId;
	}

	public String getEmployees() {
		String read, fname, employee;

		int counter = 0;

	    //Employee[] employees = new Employee[10];

	    ArrayList<Employee> employees = new ArrayList<Employee>();

		try {

		Scanner s = new Scanner(new File("rectangle.txt"));

			while(s.hasNext()) {

   				int id = s.nextInt();

			        String name = s.next();

				String lname = s.next();

   				int title = s.nextInt();

   				int hireYear = s.nextInt();

   				double salary = s.nextDouble();

					fname = name + " " + lname;

				employee = id + " " + fname + " " + title + " " + hireYear + " " + salary;

			    counter++;

			}



		} catch(FileNotFoundException e) {

	            System.out.println("There was a problem:" + e);

	        }
	return employee;
	}

	public class ExitButtonHandler implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			System.exit(0);
		}
	}

	private class AddToFileHandler implements ActionListener {
		public void actionPerformed(ActionEvent e) {
		try {
		  int id, hireYear;
		  String name, title;
		  double salary;
			id = Integer.parseInt(idTF.getText());
			name = nameTF.getText();
			title = titleCB.getSelectedItem().toString();
			hireYear = Integer.parseInt(hireyearTF.getText());
			salary = Double.parseDouble(salaryTF.getText());

		   FileWriter first = new FileWriter("rectangle.txt", true);
			  first.write(id + " " + name + " " + title + " " + hireYear + " " + salary + "\n");
		   first.close();
		} catch (IOException ex) {
			System.out.println("There was a problem: " + e);
		}
			idTF.setText(getId());
			nameTF.setText("");
			titleCB.setSelectedItem("");
			hireyearTF.setText("");
			salaryTF.setText("");
		}
	}	

	private class ClearButtonHandler implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			idTF.setText(getId());
			nameTF.setText("");
			titleCB.setSelectedItem("");
			hireyearTF.setText("");
			salaryTF.setText("");
		}
	}

	/*private class ShowEmployeesHandler implements ActionListener {
		public void actionPerformed(ActionEvent e) {
        JFrame frame = new JFrame("TextDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Add contents to the window.
        frame.add(new TextDemo());

        //Display the window.
        frame.pack();
        frame.setVisible(true);
			TextDemo.textArea.setText(getEmployees());
    		}
	}*/

	public static void main(String[] args) {
		new RectangleProgram();
	}
}

cannot find symbol
symbol : constructor JComboBox(java.lang.String)

Check the API doc: JComboBox does not have a constaructor that takes a String as a parameter.

location: employeesCB = new JComboBox(getEmployees());

Now getEmployees sounds like it should return an array or collection of Employees - which would make perfect sense as a parameter to create a combo box.
But getEmployees is actually defined as returning a single String (which happens to be the last employee read in). Obviously a mistake, since the method does create an ArrayList of Employees, but never uses it.

ps: When you check the API doc for JComboBox you will see constructors that take an array or a Vector as parameter, but not an ArrayList. So you would make your life easier if getEmployees created a Vector rather than an ArrayList. The code is exactly the same (Vector is an older class that was superseded by ArrayList, but for your purposes they are interchangeable).