Implementing Columnar Cipher Transposition In Java:

import java.io.*;
public class columnar
{
char arr[][],encrypt[][],decrypt[][],keya[],keytemp[];
public void creatematrixE(String s,String key,int row,int column)
{
arr=new char[row][column];
int k=0;
keya=key.toCharArray();
for(int i=0;i<row;i++)
{
for(int j=0;j<column;j++)
{
if(k<s.length())
{
arr[i][j]=s.charAt(k);
k++;
}
else
{
arr[i][j]=' ';
}
}
}
}
public void createkey(String key,int column)
{
keytemp=key.toCharArray();
for(int i=0;i<column-1;i++)
{
for(int j=i+1;j<column;j++)
{
if(keytemp[i]>keytemp[j])
{
char temp=keytemp[i];
keytemp[i]=keytemp[j];
keytemp[j]=temp;
}
}
}
}
public void creatematrixD(String s,String key,int row,int column)
{
arr=new char[row][column];
int k=0;
keya=key.toCharArray();
for(int i=0;i<column;i++)
{
for(int j=0;j<row;j++)
{
if(k<s.length())
{
arr[j][i]=s.charAt(k);
k++;
}
else
{
arr[j][i]=' ';
}
}
}
}
public void encrypt(int row,int column)
{
encrypt=new char[row][column];
for(int i=0;i<column;i++)
{
for(int j=0;j<column;j++)
{
if(keya[i]==keytemp[j])
{
for(int k=0;k<row;k++)
{
encrypt[k][j]=arr[k][i];
}
keytemp[j]='?';
break;
}
}
}
}
public void decrypt(int row,int column)
{
decrypt=new char[row][column];
for(int i=0;i<column;i++)
{
for(int j=0;j<column;j++)
{
if(keya[j]==keytemp[i])
{
for(int k=0;k<row;k++)
{
decrypt[k][j]=arr[k][i];
}
keya[j]='?';
break;
}
}
}
}
public void resultE(int row,int column,char arr[][])
{
System.out.println("Result:");
for(int i=0;i<column;i++)
{
for(int j=0;j<row;j++)
{
System.out.print(arr[j][i]);
}
}
}
public void resultD(int row,int column,char arr[][])
{
System.out.println("Result:");
for(int i=0;i<row;i++)
{
for(int j=0;j<column;j++)
{
System.out.print(arr[i][j]);
}
}
}
public static void main(String args[])throws IOException
{
int row,column,choice;
columnar obj=new columnar();
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Menu:\n1) Encryption\n2) Decryption");
choice=Integer.parseInt(in.readLine());
System.out.println("Enter the string:");
String s=in.readLine();
System.out.println("Enter the key:");
String key=in.readLine();
row=s.length()/key.length();
if(s.length()%key.length()!=0)
row++;
column=key.length();
switch(choice)
{
case 1: obj.creatematrixE(s,key,row,column);
obj.createkey(key,column);
obj.encrypt(row,column);
obj.resultE(row,column,obj.encrypt);
break;
case 2: obj.creatematrixD(s,key,row,column);
obj.createkey(key,column);
obj.decrypt(row,column);
obj.resultD(row,column,obj.decrypt);
break;
}
}
}