How To Make a Age Calculator in Java

This is a age calculator made in java, it's a console application by the way :)

source :

 import java.util.GregorianCalendar;
import java.util.Scanner;
import java.util.InputMismatchException;

public class age_calculator {

    public static void main(String[] args) {
        int day = 0;
        int month = 0;
        int year = 0;
        Scanner scan = new Scanner(System.in);
  try{
         System.out.print("Day: ");
         day = scan.nextInt();
         System.out.print("Month: ");
         month = scan.nextInt();
         System.out.print("Year: ");
         year = scan.nextInt();
  }
  catch(InputMismatchException e){
   System.out.println("Error: You entered an invalid number");
   System.exit(1);
  }
        System.out.println("\nYou are " + getAge(day,month,year) + " years old");
    }

    public static int getAge(int day, int month, int year){
  final int ERROR = -1;

        //initialize GregorianCalendar with current date
        GregorianCalendar cal = new GregorianCalendar();
        //constant holds current day
        final int CDAY = cal.get(GregorianCalendar.DAY_OF_MONTH);
        //constant hold current month
        final int CMONTH = cal.get(GregorianCalendar.MONTH) + 1;
        //constant to hold current year
        final int CYEAR = cal.get(GregorianCalendar.YEAR);
        //check if current day of the month is greater then birth day
        if (month == CMONTH){
            if(CDAY >= day)
                return CYEAR - year;
   if(CDAY < day)
    return CYEAR - year - 1;
        }
        //check if birth month is less then current month
        else if(month < CMONTH)
            return CYEAR - year;
        //subtract 1 from the age because  the current day in the month is less then birth date
  else
         return CYEAR - year - 1;
  return ERROR;
    }

} 

screenshot :

 

 Hope it helped you :)

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Java Port Scanner Full Source Code

Here is the full source code :

/*+---------------------------------Adeel Mahmood---------------------------------+*\

/*+---------------------------------Port Scanner----------------------------------+*\

/*=-------------------------adeelmahmood1982@ukonline.co.uk------------------------+*\

/************************************************************************************/





import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;

public class PortScanner extends Frame{



Socket s;
int startPort,endPort;
Label l1;
TextField hostName,fromPort,toPort;
TextArea log;
Label host,from,to,label;
Button scan,reset;
int fp,tp;
String h;
static boolean close=false;
Dialog d;


public PortScanner(){

Frame f=new Frame("Port Scanner");

f.setVisible(true);
f.setLayout(new GridLayout(5,1));

l1=new Label("Port Scanner version 1.0",Label.CENTER);
l1.setForeground(Color.blue);
l1.setFont(new Font("TimesRoman",Font.BOLD,20));
f.add(l1);

Panel p1=new Panel(new GridLayout(3,3));
host=new Label("Host Name:");
host.setForeground(Color.blue);
p1.add(host);
hostName=new TextField(15);
p1.add(hostName);
from=new Label("From Port:");
from.setForeground(Color.blue);
p1.add(from);
fromPort=new TextField(15);
p1.add(fromPort);
to=new Label("To Port:");
to.setForeground(Color.blue);
p1.add(to);
toPort=new TextField(15);
p1.add(toPort);

f.add(p1);

Panel p2=new Panel();
scan=new Button("Scan Now");
scan.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent r){
if(hostName.getText().equals("")){log.setText("Please complete all the required fields");
return;
}
 else if (fromPort.getText().equals("")){log.setText("Please complete all the required fields");
return;}
  else if(toPort.getText().equals("")){log.setText("Please complete all the required fields");
return;}
   
close=false;
Thread run1=new Thread(){
public void run(){

scan.setEnabled(false);
reset.setLabel("Stop");
log.setText("");
log.repaint();

h=hostName.getText();
fp=Integer.parseInt(fromPort.getText());
tp=Integer.parseInt(toPort.getText());

for(int i=fp;i<=tp;i++){
label.setText("Port "+i+" is being tested");
 if(close)
 break;
 try{
 s=new Socket(h,i);
 log.append("Port "+i+" is open."+"\n");
 log.repaint();
 s.close();
 }
 catch(Exception er){continue;}
 
}
scan.setEnabled(true);
reset.setLabel("Reset");
label.setText("Press Scan to start.");
}
};
run1.start();
}
});



reset=new Button("Reset");
reset.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent t){
Thread run2=new Thread(){
public void run(){
close=true;
hostName.setText("");
fromPort.setText("");
toPort.setText("");
}
};
run2.start();
}
});





Label empty=new Label();
p2.add(scan);
p2.add(empty);
p2.add(reset);
f.add(p2);

log=new TextArea();
f.add(log);

label=new Label("Press Scan to start.");
label.setForeground(Color.blue);
f.add(label);

f.setSize(320,460);
//f.show(true);
f.repaint();
f.setResizable(false);

f.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(1);
}
});


}

public static void main(String args[]){

new PortScanner();
}



}// end of class

Enjoy, please comment if you have any problems.

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