age calculator

hi friend,

Try this code, may this will be helpful for you.

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
public class DateDifference implements ActionListener{
    JFrame f;
    JTextField dob = new JTextField();
    JTextField age = new JTextField();
    JButton r = new JButton("Reset");   
    JButton b= new JButton("Get Age");

    String startDateString = "01/01/2000";
    SimpleDateFormat df = new SimpleDateFormat("dd/MM/yyyy");    
    public void createUI()
    {
        f=new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   
        f.setLayout(null);
        JLabel dobLabel = new JLabel("Enter Your DOB : ");
        JLabel formatLabel = new JLabel("dd/MM/yyyy");
        JLabel formatLabel2 = new JLabel("yyyy/MM/dd");
        JLabel ageLabel = new JLabel("Age As On 01/01/2000 :");        
        b.addActionListener(this);
        r.addActionListener(this);

        dobLabel.setBounds(10, 30, 100, 20);
        dob.setBounds(150,30,150,20);
        formatLabel.setBounds(300,30,100,20);
        ageLabel.setBounds(10,60,130,20);
        age.setBounds(150,60,150,20);
        formatLabel2.setBounds(300,60,100,20);
        b.setBounds(90,110,120,20);
        r.setBounds(230, 110, 120, 20);

        f.add(dobLabel);
        f.add(dob);
        f.add(formatLabel);
        f.add(ageLabel);        
        f.add(age);
        f.add(formatLabel2);
        f.add(b);
        f.add(r);
        f.setVisible(true);
        f.setSize(400,300);
    }   

    public boolean isLeapYear(int year) {
        if (year % 4 != 0) {
        return false;
        } else if (year % 400 == 0) {
        return true;
        } else if (year % 100 == 0) {
        return false;
        } else {
        return true;
        }
        }

    public boolean isZero(String str)
    {
        String[] dobArr = str.split("/");
        int i = 0;
        while(i < dobArr.length)
        {
            int num = Integer.parseInt(dobArr[i]);
            //System.out.println(num);
            i++;
            if(num == 0)
            {
                return true;
            }
        }
        return false;       
    }
    public void calculateAndShowValue(int inDay, int stDay, int inMonth, int stMonth, int inYear, int stYear)
    {
        int day = inDay - stDay;
        int month = inMonth-stMonth;
        int year = inYear-stYear;
        String dayString = Integer.toString(day);
        String monthString = Integer.toString(month);
        String yearString = Integer.toString(year);
        String date="";     
            date = yearString+"/"+monthString+"/"+dayString;
        age.setText(date);
    }

    public static void main(String[] args){
        DateDifference dd = new DateDifference();
        dd.createUI();
    }

    @Override
    public void actionPerformed(ActionEvent e) {        
        //b = (JButton)e.getSource();       
        if(e.getSource() == b)
        {
            getOperation();
        }
        else if(e.getSource() == r)
        {
            dob.setText("");
            age.setText("");
        }       
    }

Continue......

public void getOperation()
    {
        try{
        Date startDate = df.parse(startDateString);
        Calendar cal = Calendar.getInstance();        
        cal.setTime(startDate);

        String dobTextboxValue = dob.getText();
        boolean bol3 = isZero(dobTextboxValue);
        if(bol3 == true)
        {
            JOptionPane.showMessageDialog(f, "Date Shouldn't be Zero." +
                    " Try again.", "Error Message", JOptionPane.ERROR_MESSAGE);
        }
        else
        {
        Date endDate = df.parse(dobTextboxValue);
        Calendar cal2 = Calendar.getInstance();
        cal2.setTime(endDate);
        if(endDate.compareTo(startDate)==0)
        {
            JOptionPane.showMessageDialog(f, "Both Date Are Same." +
                    " Try again.", "Error Message", JOptionPane.ERROR_MESSAGE);
        }
        else if(endDate.compareTo(startDate)<0)
        {
            JOptionPane.showMessageDialog(f, "Date Should Be After"+startDate +
                    " Try again.", "Error Message", JOptionPane.ERROR_MESSAGE);
        }
        else
        {           
            int inputYear = Math.abs(cal2.get(Calendar.YEAR));
            int startYear = Math.abs(cal.get(Calendar.YEAR));
            int inputMonth = Math.abs(cal2.get(Calendar.MONTH)+1);//because month started from 0
            int startMonth = Math.abs(cal.get(Calendar.MONTH)+1);
            int inputDay = Math.abs(cal2.get(Calendar.DAY_OF_MONTH));
            int startDay = Math.abs(cal.get(Calendar.DAY_OF_MONTH));            

            if(inputDay < startDay && (inputMonth == 1 || inputMonth == 3 || inputMonth == 5 || inputMonth == 7 || inputMonth == 8 || inputMonth == 10 || inputMonth == 12))
            {
                inputDay = inputDay+31;
                inputMonth = inputMonth-1;              
                if(inputMonth < startMonth)
                {
                    System.out.println(!(inputMonth <=0));
                    inputMonth = inputMonth+12;
                    inputYear = inputYear-1;

                    calculateAndShowValue(inputDay, startDay, inputMonth, startMonth, inputYear, startYear);                    
                }
                else if(inputMonth >= startMonth)
                {
                    System.out.println("inputMonth : "+inputMonth+ "/"+!(inputMonth <=0));
                    calculateAndShowValue(inputDay, startDay, inputMonth, startMonth, inputYear, startYear);                    
                }

            }

Continue....

        else if(inputDay < startDay && (inputMonth == 2 || inputMonth == 4 || inputMonth == 6 || inputMonth == 9 || inputMonth == 11))
        {               
            if(inputMonth == 2)
            {
                boolean bol = isLeapYear(inputYear);                    
                if(bol == true)
                {
                    inputDay = inputDay+29;
                    inputMonth = inputMonth-1;                      
                    if(inputDay < startDay)
                    {
                        inputDay = inputDay+31;
                        inputMonth = inputMonth-1;
                        if(inputMonth < startMonth)
                        {
                            inputMonth = inputMonth+12;
                            inputYear = inputYear-1;

                            calculateAndShowValue(inputDay, startDay, inputMonth, startMonth, inputYear, startYear);                                                                
                        }
                        else if(inputMonth >= startMonth)
                        {
                            calculateAndShowValue(inputDay, startDay, inputMonth, startMonth, inputYear, startYear);                                
                        }                           
                    }
                    else if(inputDay >= startDay)
                    {                           
                        if(inputMonth < startMonth)
                        {
                            inputMonth = inputMonth+12;
                            inputYear = inputYear-1;
                            calculateAndShowValue(inputDay, startDay, inputMonth, startMonth, inputYear, startYear);                                                                
                        }
                        else if(inputMonth >= startMonth)
                        {
                            calculateAndShowValue(inputDay, startDay, inputMonth, startMonth, inputYear, startYear);                                
                        }
                    }
                }
                else if(bol == false)
                {
                    inputDay = inputDay+28;
                    inputMonth = inputMonth-1;
                    if(inputDay < startDay)
                    {
                        inputDay = inputDay+31;
                        inputMonth = inputMonth-1;
                        if(inputMonth < startMonth)
                        {
                            inputMonth = inputMonth+12;
                            inputYear = inputYear-1;
                            calculateAndShowValue(inputDay, startDay, inputMonth, startMonth, inputYear, startYear);                                
                        }
                        else if(inputMonth >= startDay)
                        {
                            calculateAndShowValue(inputDay, startDay, inputMonth, startMonth, inputYear, startYear);                                
                        }                           
                    }
                    else if(inputDay >=startDay)
                    {
                        if(inputMonth < startMonth)
                        {
                            inputMonth = inputMonth+12;
                            inputYear = inputYear-1;
                            calculateAndShowValue(inputDay, startDay, inputMonth, startMonth, inputYear, startYear);                                                            
                        }
                        else if(inputMonth >= startMonth)
                        {
                            calculateAndShowValue(inputDay, startDay, inputMonth, startMonth, inputYear, startYear);                                
                        }
                    }
                }
            }
            else
            {
                inputDay = inputDay+30;
                inputMonth = inputMonth-1;
                if(inputMonth < startMonth)
                {               
                    inputMonth = inputMonth+12;
                    inputYear = inputYear-1;
                    calculateAndShowValue(inputDay, startDay, inputMonth, startMonth, inputYear, startYear);                        
                }
                else if(inputMonth >= startMonth)
                {
                    calculateAndShowValue(inputDay, startDay, inputMonth, startMonth, inputYear, startYear);                        
                }
            }               
        }

Continue.....

            else if(inputDay >= startDay)
            {
                if(inputMonth < startMonth)
                {
                    inputMonth = inputMonth+12;
                    inputYear = inputYear-1;
                    calculateAndShowValue(inputDay, startDay, inputMonth, startMonth, inputYear, startYear);                                    
                }
                else if(inputMonth >= startMonth)
                {
                    calculateAndShowValue(inputDay, startDay, inputMonth, startMonth, inputYear, startYear);                    
                }
            }       
          }
        }
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }    
}