Re: How to implement jcombobox with name value pair from database?

From:

Knute Johnson <nospam@knutejohnson.com>

Newsgroups:

comp.lang.java.help

Date:

Thu, 29 Nov 2012 12:55:07 -0800

Message-ID:

<k98i3b$bgi$1@dont-email.me>

On 11/29/2012 9:14 AM, rogerdoger777 wrote:

Hello,

I have database values for name and employee id:
John 123
David 222
Kevin 444

In my app I have the employee id, and I need to update the jcombobox to make the person with employee id 222 the selected item.... HOW?

mycombobox.setSeletedIndex(222) should return David, but instead it returns the 222nd array element in the pull down....

Thanks for any and all help!

There are lots of ways to do this. Here is one simple possibility.

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

public class test extends JPanel {
     private final Vector<Employee> v = new Vector<>();
     private final Map<Integer,Employee> map = new HashMap<>();
     private final JComboBox<Employee> box;
     private final JTextField f;

     public test() {
         Employee bob = new Employee(12,"Bob");
         Employee jerry = new Employee(65,"Jerry");
         Employee jane = new Employee(70,"Jane");
         Employee sharon = new Employee(82,"Sharon");
         Employee anne = new Employee(23,"Anne");

         map.put(bob.getNumber(),bob);
         map.put(jerry.getNumber(),jerry);
         map.put(jane.getNumber(),jane);
         map.put(sharon.getNumber(),sharon);
         map.put(anne.getNumber(),anne);

         v.addAll(map.values());
         Collections.sort(v);

         box = new JComboBox<Employee>(v);
         add(box);

         f = new JTextField("",5);
         add(f);

         JButton b = new JButton("Find");
         b.addActionListener(new ActionListener() {
             public void actionPerformed(ActionEvent ae) {
                 boolean found = false;
                 try {
                     int number = Integer.parseInt(f.getText().trim());
                     Employee emp = map.get(number);
                     if (emp == null)
                         JOptionPane.showMessageDialog(test.this,
                          "Employee Doesn't Exist",
                          "Error!",
                          JOptionPane.ERROR_MESSAGE);
                     box.setSelectedItem(emp);
                 } catch (NumberFormatException nfe) {
                     JOptionPane.showMessageDialog(test.this,nfe);
                 }
             }
         });
         add(b);
     }

     public class Employee implements Comparable {
         private int number;
         private String name;

         public Employee(int number, String name) {
             this.number = number;
             this.name = name;
         }

         public String getName() {
             return name;
         }

         public int getNumber() {
             return number;
         }

         public int compareTo(Object emp) {
             return getName().compareTo(((Employee)emp).getName());
         }

         public String toString() {
             return String.format("%s %d",getName(),getNumber());
         }
     }

     public static void main(String[] args) {
         EventQueue.invokeLater(new Runnable() {
             public void run() {
                 JFrame f = new JFrame("test");
                 f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                 test t = new test();
                 f.add(t,BorderLayout.CENTER);
                 f.pack();
                 f.setVisible(true);
             }
         });
     }
}

--

Knute Johnson