Introduction
This document covers how to create a simple IMEI validator application using Java Swing.
IMEI Number
IMEI stands for International Mobile Equipment Identity. IMEI is used to identify a mobile device when it is connected to a network. Each GSM, CDMA, or satellite mobile has a unique IMEI number. This number will be printed in the device inside the battery component. A user can find his device IMEI number by calling “*#06#”. IMEI is a 15 digit number and the last digit is called as “Check Digit” and it can be identified by using Luhn algorithm.
Luhn Algorithm
Luhn algorithm is also known as “Modulus 10” algorithm. It is a simple checksum formula used to validate a variety of identification numbers, such as credit card numbers, IMEI numbers, National Provider Identifier numbers in US and Canadian Social Insurance Numbers. It was created by IBM scientist Hans Peter Luhn. Verification is done by validating check digit.
- Double the value of every second digit from the right end (first right will be check digit number).
- Add the individual digits comprising both the products from step (1) and unaffected digits in the original number.
- If the total modulo 10 is equal to 0, then the number is valid, else it is not valid.
A simple example: IMEI no of mobile-354557030810924
Step 1
Step 2
3+1+0+4+1+0+5+1+4+0+6+0+1+6+1+0+9+4+4=50
Step 3
50%10=0
. So the above number is a valid number.
Steps to Develop the Application
- Open Eclipse and create a new Java project.
- Name the project as
ImeiValidator
and click Finish.
- Now open Package explorer and right click on
ImeiValidator
.
- Create new class called
Imeivalidator
.
- Write the following code in the class:
import javax.swing.*;
import java.awt.BorderLayout;
import java.awt.event.*;
public class Imei {
JFrame frame;
JButton button;
JTextField field;
JLabel label;
JLabel warninglabel;
Box panel;
public static void main(String[] args) {
Imei hl=new Imei();
hl.gui();
}
public void gui(){
panel = Box.createVerticalBox();
frame=new JFrame();
button=new JButton("Click");
field=new JTextField(15);
field.putClientProperty("JComponent.sizeVariant", "mini");
label=new JLabel("Enter the IMEI Number");
warninglabel=new JLabel("");
panel.add(label);
panel.add(field);
panel.add(warninglabel);
panel.add(button);
frame.getContentPane().add(BorderLayout.NORTH,panel);
frame.setVisible(true);
frame.setSize(300,300);
button.addActionListener(new buttonAction());
}
public class buttonAction implements ActionListener{
public void actionPerformed(ActionEvent ev) {
int sum=0;
String ImeiNo=field.getText();
if (ImeiNo.length()!=15){
warninglabel.setText("IMEI Number should contain 15 characters");
}else
{
boolean errorflag = false;
for(int i=0;i<=14;i++){
char c=ImeiNo.charAt(i);
int number=c;
if (number<48 || number>57){
warninglabel.setText("Enter only numerals");
errorflag = true;
break;
}else
{
switch(number){
case 48: number=0;break;
case 49: number=1;break;
case 50: number=2;break;
case 51: number=3;break;
case 52: number =4;break;
case 53:number =5;break;
case 54:number=6;break;
case 55:number=7;break;
case 56:number=8;break;
case 57:number=9;break;
}
if ((i+1)%2==0){
number=number*2;
number=number/10+number%10;
}
sum=sum+number;
}
}
if(!errorflag){
if(sum%10==0){
warninglabel.setText("Valid");
}
else
{
warninglabel.setText("Invalid");
}
}
}
}
}
}
- Now run the application by Run->Run As->Java Application.
- The following window will get displayed:
- Enter the IMEI number and click ‘Click’ as shown below:
References
- http://en.wikipedia.org/wiki/Luhn_algorithm
- http://en.wikipedia.org/wiki/International_Mobile_Equipment_Identity
History
- 5th July, 2012: Initial version