electrofriends.com » Basic Programs

Java program to display Domain name service (DNS)

Ranjith — Fri, 30 Apr 2010 05:54:32 +0000

Program : Domain name service (DNS)
By : Kapil Lohia

 
import java.net.*;
 
class dns
{
	public static void main(String args[]) throws Exception
	{
		try
		{
			InetAddress[] address=InetAddress.getAllByName("java.sun.com");
			for(int j=0;j<address.length;j++)
			System.out.println(address[j]);
		}
 
		catch(Exception e)
		{
			System.out.println("Error in accessing Internet :"+e);
		}
	}
}

Java program that displays the number of characters, lines and words in a text file

Ranjith — Fri, 02 Oct 2009 18:00:29 +0000

import java.io.*;
class wordcount
{
	public static int words=0;
	public static int lines=0;
	public static int chars=0;
	public static void wc(InputStreamReader isr)throws IOException
	{
		int c=0;
		boolean lastwhite=true;
		while((c=isr.read())!=-1)
		{
			chars++;
			if(c=='\n')
				lines++;
			if(c=='\t' || c==' ' || c=='\n')
				++words;
			if(chars!=0)
				++chars;
		}	
       }
	public static void main(String[] args)
	{
		FileReader fr;
		try
		{
			if(args.length==0)
			{
				wc(new InputStreamReader(System.in));
			}
			else
			{
				for(int i=0;i<args.length;i++)
				{
					fr=new FileReader(args[i]);
					wc(fr);
				}
			}
 
		}
		catch(IOException ie)
		{
			return;
		}
		System.out.println(lines+" "+words+" "+chars);
	}
}

Output:

This is II CSE
1 4 32

Draw the frequency response
1 4 58

Java program to read and display files

Ranjith — Fri, 02 Oct 2009 17:44:29 +0000

Write a Java program that reads a file and displays the file on the screen, with a line number before each line.

import java.io.*;
class linenum
{
	public static void main(String[] args)throws IOException
	{
		FileInputStream fil;
		LineNumberInputStream line;
		int i;
		try
		{
			fil=new FileInputStream(args[0]);
			line=new LineNumberInputStream(fil);
		}
		catch(FileNotFoundException e)
		{
			System.out.println("No such file found");
			return;
		}
		do
		{
			i=line.read();
			if(i=='\n')
			{
				System.out.println();
				System.out.print(line.getLineNumber()+" ");
			}
			else
				System.out.print((char)i);
		}while(i!=-1);
		fil.close();
		line.close();
	}
}

Output:

Demo.java

class Demo
1 {
2 public static void main(java Demo beta gamma delta)
3 {
4 int n = 1 ;
5 System.out.println(“The word is ” + args[ n ] );
6 }
7 }
8?

Java program to display the information’s of the file

Ranjith — Fri, 02 Oct 2009 16:19:32 +0000

Write a Java program that reads on file name from the user then displays information about whether the file exists, whether the file is readable, whether the file is writable, the type of the file and the length of the file in bytes

import java.util.Scanner;
import java.io.File;
class FileDemo
{
	public static void main(String[] args)
	{
		Scanner input=new Scanner(System.in);
		String s=input.nextLine();
		File f1=new File(s);	
		System.out.println("File Name:"+f1.getName());
		System.out.println("Path:"+f1.getPath());
		System.out.println("Abs Path:"+f1.getAbsolutePath());
		System.out.println("Parent:"+f1.getParent());
		System.out.println("This file is:"+(f1.exists()?"Exists":"Does not exists"));
		System.out.println("Is file:"+f1.isFile());
		System.out.println("Is Directory:"+f1.isDirectory());
		System.out.println("Is Readable:"+f1.canRead());
		System.out.println("IS Writable:"+f1.canWrite());
		System.out.println("Is Absolute:"+f1.isAbsolute());
		System.out.println("File Last Modified:"+f1.lastModified());
		System.out.println("File Size:"+f1.length()+"bytes");
		System.out.println("Is Hidden:"+f1.isHidden());
	}
}

Output:

Fibonacci.java
File Name:Fibonacci.java
Path: Fibonacci.java
Abs Path: c:\sameer\Fibonacci.java
Parent: Null
This file is:Exists
Is file:true
Is Directory:false
Is Readable:true
Is Writable:true
Is Absolute:false
File Last Modified:1206324301937
File Size: 406 bytes
Is Hidden:false

Java program using String Tokenizer class

Ranjith — Fri, 02 Oct 2009 15:48:08 +0000

Write a Java program that reads a line of integers and displays each integer and sum of all integers using String Tokenizer class

import java.util.StringTokenizer;
import java.util.Scanner;
class tokens
{
	public static void main(String[] args)
	{
		Scanner input=new Scanner(System.in);
		String sentence=input.nextLine();
		String temp;
		int k,total=0;
		StringTokenizer s1=new StringTokenizer(sentence);
		System.out.println("Total Number of tokens:"+s1.countTokens());
		while(s1.hasMoreTokens())
		{
			temp=s1.nextToken();
			k=Integer.parseInt(temp);
			total+=k;
			System.out.print(k+"\t");
		}
		System.out.println("Sum of tokens :"+total);
	}
}

Output:

12 43 78 98
Total Number of tokens:4
12 43 78 98
Sum of tokens : 231

123 456 798
Total number of tokens:3
123 456 798
Sum of tokens:1377

Java Program to multiply two matrices

Ranjith — Fri, 02 Oct 2009 15:33:11 +0000

import java.util.Scanner;
class matmul
{
	public static void main(String args[])
	{
		int a[][]=new int[3][3];
		int b[][]=new int[3][3];
		int c[][]=new int[3][3];
		System.out.println("Enter the first matrix:");
		Scanner input=new Scanner(System.in);
		for(int i=0;i<3;i++)
			for(int j=0;j<3;j++)
			    a[i][j]=input.nextInt();
 
		System.out.println("Enter the second matrix:");
		for(int i=0;i<3;i++)
			for(int j=0;j<3;j++)
				b[i][j]=input.nextInt();
		System.out.println("Matrix multiplication is as follows:");
		for(int i=0;i<3;i++)
		{
			for(int j=0;j<3;j++)
			{
				c[i][j]=0;
				for(int k=0;k<3;k++)
				{
				  c[i][j]+=a[i][k]*b[k][j];
	           			}
			}
	    	}
	    	for(int i=0;i<3;i++)
			{
			for(int j=0;j<3;j++)
	 		{
	     		System.out.print(a[i][j]+"\t");
    			}
    			System.out.println("\n");
        		}
        		System.out.println("\n");
        		for(int i=0;i<3;i++)
			{
			for(int j=0;j<3;j++)
	 		{
	     		System.out.print(b[i][j]+"\t");
    			}
    			System.out.println("\n");
        		}	
        		System.out.println("\n");
	    	for(int i=0;i<3;i++)
			{
			for(int j=0;j<3;j++)
	 		{
	     		System.out.print(c[i][j]+"\t");
    			}
    			System.out.println("\n");
        		}		   	
	}
}

Output:

Enter the first matrix:
1 2 3 4 5 6 7 8 9

Enter the second matrix:
9 8 7 6 5 4 3 2 1

Matrix multiplication is as follows:
1 2 3
4 5 6
7 8 9

9 8 7
6 5 4
3 2 1

30 24 18
84 69 54
138 114 90

Java program to sort a given list of names in ascending order

Ranjith — Fri, 02 Oct 2009 15:19:46 +0000

class sorting
{
	public static void main(String[] input)
	{
		int k=input.length;
		String temp=new String();
		String names[]=new String[k+1];
		for(int i=0;i<k;i++)
		{
			names[i]=input[i];
		}
		for(int i=0;i<k;i++)
			for(int j=i+1;j<k;j++)
			{
				if(names[i].compareTo(names[j])<0)
				{
					temp=names[i];
					names[i]=names[j];
					names[j]=temp;
				}
			}
System.out.println(“Sorted order is”);
for(int i=0;i<k;i++)
{
			System.out.println(names[i]);
}
     }
}

Output:

Java sorting Harish Ramesh Mahesh Rakesh
Sorted order is
Ramesh
Rakesh
Mahesh
Harish

Java sorting sai hari teja ravi sandeep
Sorted order is
teja
sandeep
sai
ravi
hari

Java program that checks whether the given string is palindrome or not

Ranjith — Fri, 02 Oct 2009 15:12:38 +0000

class palindrome
{
public static void main(String[] args)
{
StringBuffer s1=new StringBuffer(args[0]);
StringBuffer s2=new StringBuffer(s1);
s1.reverse();
System.out.println(“Given String is:”+s2);
System.out.println(“Reverse String is”+s1);
if(String.valueOf(s1).compareTo(String.valueOf(s2))==0)
System.out.println(“Palindrome”);
else
System.out.println(“Not Palindrome”);
}
}

Output:

Java palindrome madam
Given String is:madam
Reverse String is madam
Palindrome

Java palindrome harish
Given String is:harish
Reverse String is hsirah
Not Palindrome

Java program to print the prime numbers

Ranjith — Fri, 02 Oct 2009 15:08:10 +0000

Write a Java program that prompts the user for an integer and then prints out all prime numbers up to that integer.

import java.util.Scanner;
class prime
{
	public static void main(String[] args)
	{
		int n,p;
		Scanner s=new Scanner(System.in);
		System.out.println(“Enter upto which number prime numbers are needed”);
		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);
		}
	}
}

Output:

Enter upto which number prime numbers are needed:20
2
3
5
7
11
13
17
19

Enter up to which number prime numbers are needed:35

2
3
5
7
11
13
17
19
23
29
31

Java program to print Fibonacci sequence

Ranjith — Fri, 02 Oct 2009 14:50:28 +0000

Write a Java program that uses both recursive and non-recursive functions to print nth value in the Fibonacci sequence

Without recursion:

import java.util.Scanner;
class fibonacci
{
	public static void main(String[] input)
	{
		int x,y;
		x=Integer.parseInt(input[0]);
		y=Integer.parseInt(input[1]);
		Scanner s=new Scanner(System.in);
		System.out.println(“Enter the value of n:”);
int n=s.nextInt();
		int z[]=new int[n];
		z[0]=x;
		z[1]=y;
		for(int i=2;i<n;i++)
		{
			z[i]=z[i-1]+z[i-2];
		}
		for(int i=0;i<n;i++)
		{	
			System.out.println(z[i]);
		}
	}
}

With recursion:

import java.util.Scanner;
class fibonacci
{
	public static void main(String[] args)
	{
		Scanner s=new Scanner(System.in);
		System.out.println(“Enter the value of n:”);
		int n=s.nextInt();
		fiboni f1=new fiboni();
		System.out.println(f1.fibon(n));
	}
}
class fiboni
{
	public int fibon(int a)
	{
		if(a==0 || a==1)
			return 1;
		else
			return fibon(a-1)+fibon(a-2);
	}
}

Output:

1
1
2
3
5
8
13
21
34
55