Free Java Project

Java Program to Convert Decimal Number to Roman Number

Objectives :

  • Convert Decimal number to Roman number
  • Convert Decimal numeral to Roman numeral
  • How to convert a decimal number to roman number
  • Write a program that converts a decimal number to Roman number.
  • Write a program that converts a decimal number to Roman number. Decimal Number is accepted using Scanner class at the time of execution.
  • Write a program that converts a decimal number to Roman number. Decimal Number is accepted as command line input at the time of execution.

 

Program : 

Java program that converts a decimal number to Roman number. Decimal Number is accepted using Scanner class at the time of execution.

[sourcecode lang=”java”]

 

import java.util.Scanner;

public class DecimalToRoman {

private static String toRoman(int num) {
String[] romanCharacters = { "M", "CM", "D", "C", "XC", "L", "X", "IX", "V", "I" };
int[] romanValues = { 1000, 900, 500, 100, 90, 50, 10, 9, 5, 1 };
String result = "";

for (int i = 0; i < romanValues.length; i++) {
int numberInPlace = num / romanValues[i];
if (numberInPlace == 0) continue;
result += numberInPlace == 4 && i > 0? romanCharacters[i] + romanCharacters[i – 1]:
new String(new char[numberInPlace]).replace("\0",romanCharacters[i]);
num = num % romanValues[i];
}
return result;
}

public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.print("Enter a number : ");
int decimal = scanner.nextInt();
System.out.println(toRoman(decimal));
}

}

[/sourcecode]

Output :

Enter a number : 1234

MCCXXXIV

Java program that converts a decimal number to Roman number. Decimal Number is accepted as command line input at the time of execution.

[sourcecode lang=”java”]

public class DecimalToRoman {

private static String toRoman(int num) {
String[] romanCharacters = { "M", "CM", "D", "C", "XC", "L", "X", "IX", "V", "I" };
int[] romanValues = { 1000, 900, 500, 100, 90, 50, 10, 9, 5, 1 };
String result = "";

for (int i = 0; i < romanValues.length; i++) {
int numberInPlace = num / romanValues[i];
if (numberInPlace == 0) continue;
result += numberInPlace == 4 && i > 0? romanCharacters[i] + romanCharacters[i – 1]:
new String(new char[numberInPlace]).replace("\0",romanCharacters[i]);
num = num % romanValues[i];
}
return result;
}

public static void main(String[] args) {
if(args.length<1 || args.length>1){
System.out.println("Wrong input");
}else{
String number = args[0];
int decimal = Integer.parseInt(number);
System.out.println(toRoman(decimal));
}
}

}

[/sourcecode]

Java Program to find prime number upto N number

Objectives :

  • Write a Java program to find prime number upto N number
  • Write a Java program to print prime number upto N number
  • Write a Java program to find prime number upto N number using Command Line Arguments
  • Write a Java Program to find prime number upto N number via Command Line Arguments
  • Write a Java program to find prime number upto N number using Scanner class

 

Java Program / Code :

Method 1 : Java Program to find Prime Number upto N number using Scanner class

[sourcecode lang=”Java”]

import java.util.Scanner;
class PrimeNumber
{
public static void main(String[] args)
{
int n,p;
Scanner s=new Scanner(System.in);
System.out.println(“Enter number : ”);
n=s.nextInt();
for(int i=2;i<n;i++)
{
p=0;
for(int j=2;j<i;j++)
{
if(i%j==0)
p=1;
}
if(p==0){
System.out.println(i);
}
}
}
}
[/sourcecode]

Method 2 : Java Program to find Prime Number upto N number using Scanner class and writing function to find prime number

Method isPrime() for checking if a number is prime or not

[sourcecode lang=”java”]
public class PrimeNumber{
public boolean isPrime(int num) {
if ( num < 2 ){
return false;
}
for (int i = 2; i <= Math.sqrt(num); i++) {
if ( num % i == 0 ) {
return false;
}
}
return true;
}
}

// Mock Test Class to test above code
import java.util.Scanner;

public class Demo
{
public static void main(String[] args)
{
Scanner scanner = new Scanner(System.in);

System.out.println("Please enter a number: ");
int num = scanner.nextInt();

if ( num < 2 ) {
System.out.println("\n There are no Prime Numbers available");
System.exit(0);
}
System.out.println("\n Prime Numbers from 1 to "+ num);
PrimeNumber primeNum = new PrimeNumber();

for (int i = 3; i <= num; i++) {
if ( primeNum.isPrime(i) ) {
System.out.print(", " + i);
}
}
}
}
[/sourcecode]

Method 3 : Java Program to find Prime Number upto N number using Command line input

[sourcecode lang=”Java”]

class PrimeNumber
{
public static void main(String[] args)
{
int n,p;
n=Integer.parseint(args[0]);
for(int i=2;i&lt;n;i++)
{
p=0;
for(int j=2;j&lt;i;j++)
{
if(i%j==0)
p=1;
}
if(p==0){
System.out.println(i);
}
}
}
}
[/sourcecode]

Steps to run above program via command line :

  1. Compilation : C:\JavaPrograms>javac PrimeNumber.java
  2. Interpretation : C:\JavaPrograms>java PrimeNumber 20

Output :

2

3

5

7

11

13

17

19

Get MAC Address using Java

Free Source Code

Free Source Code

Objective :

* How to get the MAC Address of a computer?
* How to get the MAC Address of a computer using Java?
* How to get the MAC Address of a computer via programming?

[sourcecode language=”java”]
import java.net.*;

class GetMac
{
public static void main(String arg[])
{
try
{
InetAddress address = InetAddress.getLocalHost();
NetworkInterface nwi = NetworkInterface.getByInetAddress(address);
byte mac[] = nwi.getHardwareAddress();
System.out.println(mac);
}
catch(Exception e)
{
System.out.println(e);
}
}
}
[/sourcecode]

Note : This code will return only the first net address; if you need other detils too, get a list.

Posted from WordPress for Android

Check your Operating System & its version

Free Source Code

Free Source Code

Objective :

  • How to check your operating system by programming?
  • How to check your operating system by Java programming?
  • Write Java program to check operating system & its version

Hi folks,

Hey guys, if you want to know which operating system you are using & its version, there are 2 ways to do it as follows;

  • Using Command Prompt
  • Using Programming

1. Using Command Prompt

  • Go to Start Menu
  • Go to Run
  • Type cmd & press Enter/return. Command Prompt will open.
  • Type ver & press Enter/return, you will get the Name of your OS & its Version that you are using
Here I have used, ver command one of the DOS commands which returns Name of Operating System and its version.

2. Using Programming

Here we are using a Java Program to find the operating system you are using & its version :
[sourcecode language=”java”]
package com.si.java.utility.os;

/**
*
* Language : Java
* File : MyOS.java
* Date : Tuesday, October 5, 2010
* @author Atul Palandurkar
* Email : atul.palandurkar@gmail.com
* Website : www.shardainfotech.com
* Blog : http://atulpalandurkar.wordpress.com
*
*/

public class MyOS
{
public static void main(String[] arg)
{
//To find the name of operating system.
String myOS = System.getProperty("os.name");
System.out.println("Operating System : " + myOS);

//To find the version of operating system.
String myOSVersion = System.getProperty("os.version");
System.out.println("Version : " + myOSVersion);
}
}
[/sourcecode]

So, what are you waiting for?
Use it to create various system utilities & have fun.

Find your IP Address

Free Source Code

Free Source Code

Objective :

  • How to find IP address of your computer?
  • How to find IP address by programming?
  • How to find IP address by Java programming?
  • Write a Java program to find IP Address.

Hello guys.

Do you want to find your IP Address?

There are following ways to check / find your IP Address

  1. Using Command prompt.
  2. Using Programming.
1. Using Command Prompt :
  • Open Command Prompt.
  • Type “ipconfig” without quotes & Press Enter. IP Address will be displayed.
2. Using Programming :
Here we are using a Java Program to find the IP Address. The Java Program to find the IP Address is as follows;

[sourcecode language=”java”]

package com.si.java.utility.ip;

import java.net.InetAddress;

/**
*
* Language : Java
* File : IPAddressFinder.java
* Date : Saturday, October 2, 2010
* @author Atul Palandurkar
* Email : atul.palandurkar@gmail.com
* Website : www.shardainfotech.com
*
*/

public class IPAddressFinder
{

public static void main(String[] args)
{
try
{
InetAddress ia = InetAddress.getLocalHost();
String ip = ia.getHostAddress();
System.out.println("Your IP Address :- "+ip);
}
catch (Exception ex)
{
ex.printStackTrace();
}
}
}
[/sourcecode]

The above code can be very useful to find the IP address of your computer, as well as this can be used to find the IP address of the user in internet based applications with a little change in it.
Use it & have fun.
..