The code below is to create a deterministic finite automata. It just builds the logic of a dfa. The gui can be created very easily.

import javax.swing.JOptionPane;
import javax.swing.*;
import java.util.*;
public class dfa {

static String alphabet,son,retrn;
static int comma=0;
static int acomma=0;
static int number=0;
static String[][] st=new String[50][50];
public static void main(String args[]){


alphabet=JOptionPane.showInputDialog(null,"Alphabet?");

for( int i=0; i if( alphabet.charAt(i) == ',' )
comma++;
}

String states=JOptionPane.showInputDialog(null,"# of states");
number=Integer.parseInt(states);

for(int i=0; i int k=0;
for(int j=0; j<(alphabet.length()-comma);j++)
{

st[i][j]=JOptionPane.showInputDialog(null,"q"+i+","+alphabet.charAt(k));


System.out.print("q"+i+"--"+alphabet.charAt(k)+"-->"+"q"+st[i][j]+"\n");

k=k+2;
}

}


String start = JOptionPane.showInputDialog(null,"starts state?");
int start1=Integer.parseInt(start);
String accept = JOptionPane.showInputDialog(null,"accept states?");

for( int i=0; i if( accept.charAt(i) == ',' )
acomma++;
}

int[] accepts= new int[(accept.length()-acomma)];

int l=0;
for(int i=0; i<(accept.length()-acomma); i++){
accepts[i]=Integer.parseInt(Character.toString(accept.charAt(l)));
l=l+2;
System.out.print(accepts[i]);
}

System.out.println("start state"+start);
System.out.println("Accept state"+accept);

String strng=JOptionPane.showInputDialog(null,"String?");
System.out.println(strng);

int[] durums=new int[strng.length()];

for(int i=0; i if(i==0){
durums[i]=dfa(start1,strng.charAt(i));
}
else{
durums[i]=dfa(durums[i-1],strng.charAt(i));
}
System.out.println(durums[i]);
}

int kontrol=durums[(strng.length()-1)];

int kabuluzun=accepts.length;

for(int i=0; i if(kontrol==accepts[i]){
System.out.println("ACCEPTED!!!");
break;
}
else if(kontrol!=accepts[i]){
System.out.println(" NOT ACCEPTED!!!");
break;
}
}

//DFA METHOD!!!
public static int dfa(int durum, char deger ){

int deger1=0;
int sondurum=0;
for(int i=0;i

if(deger==alphabet.charAt(i)){
deger1=i;}

else{
for(int j=0; j<(alphabet.length()-comma-1);j++){

i=i+2;
if(deger==alphabet.charAt(i)){
deger1=i-1;
break;
}
}
}

sondurum=Integer.parseInt(st[durum][deger1]);

}
return sondurum;
}
}