PlayFair cipher

import java.io.*;
class PlayFairDemo
{
String key=new String();
String key2=new String();
String text=new String();
char key_array[][]=new char[5][5];
public void keySetter(String k)
{
String str=new String();
boolean test=false;
str=str+k.charAt(0);
for(int i=1;i<k.length();i++)
{
for(int j=0;j<str.length();j++)
if(k.charAt(i)==str.charAt(j) || k.charAt(i)=='j')
test=true;
if(!test)
str=str+k.charAt(i);
test=false;
}
key=str;
matrixBuilder(key);
}
public void matrixBuilder(String k)
{
key2=key2+key;
boolean test=false;
char current;
for(int i=0;i<26;i++)
{
current=(char)(i+97);
for(int j=0;j<key.length();j++)
if(current=='j' || current==key.charAt(j))
test=true;
if(!test)
key2=key2+current;
test=false;
}
System.out.println(key2);
for(int i=0;i<5;i++)
for(int j=0;j<5;j++)
key_array[i][j]=key2.charAt(i*5+j);
for(int i=0;i<5;i++)
{
for(int j=0;j<5;j++)
System.out.print(key_array[i][j]+" ");
System.out.println();
}
}
public void stringConversion(String input)
{
String altered=new String();
altered=input.replace('j','i');
for(int i=0;i<altered.length();i++)
if(i>0 && altered.charAt(i)==altered.charAt(i-1))
altered=altered.substring(0,i)+'x'+altered.substring(i);
if((altered.length()%2)!=0)
altered=altered+'x';
text=altered;
System.out.println(text);
}
public int[] getDimensions(char letter)
{
int key[]=new int[2];
for (int i=0 ; i<5 ;i++)
for (int j=0 ; j<5 ; j++)
if(key_array[i][j] == letter)
{
key[0]=i;
key[1]=j;
break;
}
return key;
}
public void Encrypt()
{
char a,b;
String Code="";
int c[]=new int[2];
int d[]=new int[2];
for(int i=0;i<text.length();i=i+2)
{
a=text.charAt(i);
b=text.charAt(i+1);
c=getDimensions(a);
d=getDimensions(b);
if(c[0]==d[0])
{
if (c[1]<4)
c[1]++;
else
c[1]=0;
if(d[1]<4)
d[1]++;
else
d[1]=0;
}
else if(c[1]==d[1])
{
if (c[0]<4)
c[0]++;
else
c[0]=0;
if(d[0]<4)
d[0]++;
else
d[0]=0;
}
else
{
int temp=c[1];
c[1]=d[1];
d[1]=temp;
}
Code=Code+key_array[c[0]][c[1]]+key_array[d[0]][d[1]];
}
System.out.println("Encrypted text:"+Code);
}
public void Decrypt()
{
char a,b;
String Code="";
int c[]=new int[2];
int d[]=new int[2];
for(int i=0;i<text.length();i=i+2)
{
a=text.charAt(i);
b=text.charAt(i+1);
c=getDimensions(a);
d=getDimensions(b);
if(c[0]==d[0])
{
if (c[1]>0)
c[1]--;
else
c[1]=4;
if(d[1]>0)
d[1]--;
else
d[1]=4;
}
else if(c[1]==d[1])
{
if (c[0]>0)
c[0]--;
else
c[0]=4;
if(d[0]>0)
d[0]--;
else
d[0]=4;
}
else
{
int temp=c[1];
c[1]=d[1];
d[1]=temp;
}
Code=Code+key_array[c[0]][c[1]]+key_array[d[0]][d[1]];
}
System.out.println("Decrypted text:"+Code);
}
public static void main(String args[])throws IOException
{
String s,s2,s3,s4;
int ch;
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
PlayFairDemo p=new PlayFairDemo();
System.out.println("Enter the key:");
s4=br.readLine();
p.keySetter(s4);
do{
System.out.println("Enter Your Choice:\n1.Encrypt\n2.Decrypt\n3.Exit");
s=br.readLine();
ch=Integer.valueOf(s).intValue();
switch(ch)
{
case 1 : System.out.println("Enter Text to be Encrypted:");
s2=br.readLine();
s2=s2.toLowerCase();
p.stringConversion(s2);
p.Encrypt();
break;
case 2 : System.out.println("Enter Text to be Decrypted:");
s3=br.readLine();
s3=s3.toLowerCase();
p.stringConversion(s3);
p.Decrypt();
break;
case 3 : System.exit(0);
}
}while(ch<3);
}
}