Practice simplest java programe

How to make functions in java:

class Fuction

{

private int  len,hei;

public void setData( int i , int  h)

{

len=i;

hei=h;

}

public void showData()

{

System.out.println("Length is:" +len);

System.out.println("Height is:" +hei);

    System.out.println("Total length multiple height is:" +(len*hei));

}

public static void main(String args[])

{

Fuction u= new Fuction();

u.setData(13,6);

u.showData();

}

}

How to user input value: 

import java.util.*;

public class User

{

public static void main(String args[])

{

Scanner u = new Scanner(System.in);

System.out.print("Enter a number:");

int a=u.nextInt();

int s=a+10;

System.out.println("You entered number:" +s);

}

}

How to print current date/time:

import java.util.*;

class DateTime

{

public static void main(String args[])

{

Calendar obj = new GregorianCalendar();

int h , m , s;

h = obj.get(Calendar.HOUR);

m = obj.get(Calendar.MINUTE);

s = obj.get(Calendar.SECOND);

System.out.println(h+" : " +m+ " : "+s);

}

}

How to print table:

import java.util.*;

public class User

{

public static void main(String args[])

{

Scanner u = new Scanner(System.in);

System.out.print("Enter a number:");

int a=u.nextInt();

int s=a+10;

System.out.println("You entered number:" +s);

}

}