Source code for project developed in core Java " RAILWAY RESERVATION SYSTEM "

/*This is a java project source code for "RAILWAY RESERVATION MANAGEMENT SYSTEM" developed in core java technology */

 I thorougly tested the program myself and it works well ,after all if you need any  help then contact me my email is written above bbye ..
                                                                                      ------by gaurav kumar yadav

email:-gaurav10610@gmail.comif you like this code then you can subscribe me on facebook link:-

and subscribe my blog:-www.javaprogrammingstuff.blogspot.com

To download complete source code of the project click here.. DOWNLOAD

Deterministic finite automata ( DFA ) implemented using Java....

 

This is a java program to simulate the DFA( deterministic finite automata ) developed using J2SE . It works for any general dfa that you have specified through five tuples during the execution of the program. 

To know that how to give input to the program please click here

here is the code  :-

       

import java.io.*;
import java.util.*;
public class Dfasimulator {

 public int[][] Transition = new int[20][20];
 public int alphaset, stateset;
 public ArrayList < Character > alphabet;
 public Set < Integer > finalstates;

 public void builtdfa() throws Exception {

  BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
  System.out.println("please enter the no. of alphabets in the alphabet set of DFA");
  alphaset = Integer.parseInt(br.readLine());
  //System.out.println(alphaset);
  System.out.println("please enter the no. of states in the set of DFA");
  stateset = Integer.parseInt(br.readLine());

  System.out.println("please enter all the alphabets of the DFA simultaneosly");
  String alphabets = br.readLine();

  alphabet = new ArrayList < Character > ();
  for (int i = 0; i < alphabets.length(); i++) {
   alphabet.add(alphabets.charAt(i));

  }
  //System.out.println(alphabet);

  for (int s = 0; s < stateset; s++) {
   System.out.println("enter the row entries of the transition table");
   for (int r = 0; r < alphaset; r++) {
    int int1 = Integer.parseInt(br.readLine());
    Transition[s][r] = int1;
   }
  }

  finalstates = new HashSet < Integer > ();
  System.out.println("please enter the final states of the DFA\n");
  System.out.println("when you are done of giving the inputs enter -2 to stop feeding final states");

  int int2 = Integer.parseInt(br.readLine());

  while (int2 != -2) {
   finalstates.add(int2);
   int2 = Integer.parseInt(br.readLine());
  }
  System.out.println(finalstates);
  DfaTest();
 }

 public void DfaTest() throws Exception {
  BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
  int state;
  System.out.println("enter the starting state");
  state = Integer.parseInt(br.readLine());

  System.out.println("give input to the DFA\n");
  System.out.println("end your input with # character\n");
  String input = br.readLine();
  int index = 0;

  while (input.charAt(index) != '#') {
   char char1 = input.charAt(index);
   int index1 = alphabet.indexOf(char1);
   state = Transition[state][index1];
   index++;
  }
  System.out.println("\nfinal state after giving the input is " + state);
  if (finalstates.contains(state))
   System.out.print("your input string is accepted by the DFA");
  else
   System.out.println("the input string is rejected by  the DFA");
 }

 public static void main(String args[]) throws Exception {
  Dfasimulator raw = new Dfasimulator();
  raw.builtdfa();
  //System.out.println(raw.alphaset);
 }
}

       
 

Encryption and Decryption of text documents using java...

This is a java program for decryption and encryption purpose of text documents it could be run everywhere and can be used to encrypt and decrypt such confidential text documents .

I use the concept of serialization and some mathematical algorithm to encrypt and decrypt the document.After encryption the program will generate a cipher text and a decryption key both of which are ".ser" files.

How to use :-1. If you are encrypting the text file then you have to give the path of that text document upto .txt extension like "D:\power.txt".

2. If you are decrypting the file then you have to give the path of the cipher text and the decryption key both of which are ".ser" files for example:- 

cipher Text - "d:\cipher.ser" 

decryption Key - "d:\key.ser"

You can use this program to extent your big projects.

algorithm of the code is here

here is the code....

       



import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.InputStreamReader;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.PrintWriter;

public class Encrypt {

 int len;
 public double yo;
 public int[] key;
 static String str;
 static String data;
 public String cipherPath;
 public String plainPath;
 public String original1;
 public int[] cipher;
 public int[] c;
 public int[] d;
 public int[] plain1;
 public int[] plain2;
 public int[] ascii;
 public int[] plain;
 static char[] arrow;
 char[] original;

 /**
  * This function starts the encryption process
  * @param ascii contains ascii values of all the characters from the input file
  */
 public void Encryption_logic(int[] ascii) {
  c = new int[ascii.length / 2];
  d = new int[ascii.length / 2];
  if (ascii.length % 2 == 0) {
   for (int k = 0; k < ascii.length / 2; k++) {
    c[k] = ascii[k];
    c[k] = c[k] * (k + 2);
   }
   for (int f = 0; f < ascii.length / 2; f++) {
    d[f] = ascii[ascii.length / 2 + f];
    d[f] = d[f] * (f + 3);
   }
  }
  ciphertext(c, d);
 }

 /**
  * This function prepares the final cipher text(encrypted Text) and decryption key and writes it on to the persistent storage
  * @param c
  * @param d
  */
 public void ciphertext(int[] c, int[] d) {
  try {

   cipher = new int[c.length + d.length];

   for (int q = 0, l = 0, p = 0; q < c.length + d.length; q++) {

    if (q % 2 == 0 || q == 0) {
     cipher[q] = c[l];
     l++;
    }

    else {
     cipher[q] = d[p];
     p++;
    }
   }

   System.out
     .println("Please Enter The Location Where You Want To Save The Encrypted Cipher Text And The Encryption Key");
   BufferedReader br2 = new BufferedReader(new InputStreamReader(
     System.in));
   cipherPath = br2.readLine();
   FileOutputStream file2 = new FileOutputStream(cipherPath
     + "cipher.ser");
   ObjectOutputStream obj2 = new ObjectOutputStream(file2);
   obj2.writeObject(cipher);
   obj2.close();
   System.out
     .println("your encrypted text and key is saved to the location:- "
       + cipherPath);

   key = new int[5];
   key[0] = cipher[0] + cipher[cipher.length - 2];
   key[1] = d[0];
   key[2] = d[0] + c[0];
   key[3] = c[c.length - 1];
   key[4] = (cipher.length - 1);

   FileOutputStream file3 = new FileOutputStream(cipherPath
     + "key.ser");
   ObjectOutputStream obj3 = new ObjectOutputStream(file3);
   obj3.writeObject(key);
   obj3.close();

  } catch (Exception e) {
   System.out.println("\nexception caught");
  }
 }
 
/**
 * 
 * @param cipher is the array containing cipher text
 * @param key is the decryption key
 */
 public void decryption_logic(int[] cipher, int[] key) {
  try {
   plain1 = new int[cipher.length / 2];
   plain2 = new int[cipher.length / 2];

   if ((key[0] == (cipher[0] + cipher[cipher.length - 2]))
     && (key[4] == cipher.length - 1)
     && (key[2] == (cipher[0] + cipher[1]))
     && (key[1] == cipher[1])
     && (key[3] == cipher[cipher.length - 2])) {
    for (int p = 0, a = 0, z = 0; p < cipher.length; p++) {

     if (p % 2 == 0 || p == 0) {
      plain1[a] = cipher[p];
      plain1[a] = plain1[a] / (a + 2);
      a++;
     }

     else {
      plain2[z] = cipher[p];
      plain2[z] = plain2[z] / (z + 3);
      z++;
     }

    }
   }

   else {
    System.out.println("\ndecryption key is not valid");
   }

   plain = new int[plain1.length + plain2.length];
   for (int e = 0, b = 0; e < (plain1.length + plain2.length); e++) {
    if (e < plain1.length) {
     plain[e] = plain1[e];
    } else {
     plain[e] = plain2[b];
     b++;
    }
   }
   originalText(plain);
  } catch (Exception u) {
   u.printStackTrace();
  }
 }

 /**
  * This function will write the original text to the text file after decryption and store the file at user specified location
  * @param plain
  * @return
  */
 public char[] originalText(int[] plain) {
  try {
   if (plain[plain.length - 1] == '?') {
    original = new char[plain.length - 1];
    System.out.println("\n");

    for (int o = 0; o < (plain.length - 1); o++) {
     original[o] = (char) plain[o];
     // System.out.print(original[o]);
    }
   } else {
    original = new char[plain.length];
    System.out.println("\n");

    for (int o = 0; o < plain.length; o++) {
     original[o] = (char) plain[o];
     // System.out.print(original[o]);
    }
   }

   original1 = new String(original);
   // System.out.println(original1);
   System.out
     .println("\nPlease enter the location where you want to store the plain text after decryption \n");

   BufferedReader br4 = new BufferedReader(new InputStreamReader(
     System.in));
   plainPath = br4.readLine();
   File file4 = new File(plainPath + "plainText.txt");
   FileWriter fw = new FileWriter(file4);
   PrintWriter pw = new PrintWriter(fw);
   pw.write(original1);
   System.out.println("your plainText is stored at location :-"
     + plainPath);
   pw.flush();
   pw.close();
  } catch (Exception q) {
   q.printStackTrace();
  }
  return original;
 }
/**
 * initializing an integer array with the ascii values of the characters from @arrow
 * @param arrow
 */
 public void asciiarray(char[] arrow) {
  int j;
  ascii = new int[arrow.length];
  System.out.print("\n");
  for (j = 0; j < arrow.length; j++) {
   ascii[j] = arrow[j];
  }
  Encryption_logic(ascii);
 }
/**
 * 
 * Here '?' is added at the last index of string if its length is not even to make the algorithm work
 * and initializing a character array with characters from @data
 * @param data contains whole input file data
 */
 public void initial(String data) {
  int i;
  
  if (data.length() % 2 != 0) {
   arrow = new char[data.length() + 1];
   arrow[data.length()] = '?';
  } else {
   arrow = new char[data.length()];
  }
  for (i = 0; i < data.length(); i++) {
   arrow[i] = data.charAt(i);
  }
 }

 /**
  * This function will take the file to be encrypted and store its whole content in a single String object.
  * @return
  */
 public String inputData() {
  System.out
    .println("Please Enter The Address Of the File To Be Encrypted\n");
  try {
   BufferedReader br6 = new BufferedReader(new InputStreamReader(
     System.in));
   str = br6.readLine();
   String[] fileExtension=str.split("\\.");
   if(!fileExtension[1].equals("txt")){
    System.out.println("File to be encrypted is not a text file ...Plese try again");
   }
   
   File file = new File(str);
   FileReader file1 = new FileReader(file);
   BufferedReader br = new BufferedReader(file1);
   String line = null;
   StringBuilder sb = new StringBuilder();
   String is = System.getProperty("line.separator");
   while ((line = br.readLine()) != null) {
    sb.append(line);
    sb.append(is);
   }
   data = sb.toString();
   // System.out.println(data);
   br.close();

  } catch (Exception e) {
   e.printStackTrace();
  }
  return data;
 }

 public static void main(String args[]) {
  int choice;

  Encrypt ko = new Encrypt();
  try {
   BufferedReader br1 = new BufferedReader(new InputStreamReader(
     System.in));
   System.out
     .println("what you want to do ???encryption or decryption enter 1 for encryption and 2 for decryption \n");
   choice = Integer.parseInt(br1.readLine());

   switch (choice) {
   case 1:
    ko.inputData();
    ko.initial(data);
    ko.asciiarray(arrow);
    break;

   case 2:
    String encryptedPath;
    String keyPath;
    BufferedReader br5 = new BufferedReader(new InputStreamReader(
      System.in));
    System.out
      .println("please enter the location of the cipher text\n");
    encryptedPath = br5.readLine();
    System.out
      .println("please enter the location of the decryption key\n");
    keyPath = br5.readLine();

    FileInputStream file5 = new FileInputStream(encryptedPath);
    ObjectInputStream read = new ObjectInputStream(file5);
    int[] cipher1 = (int[]) read.readObject();

    FileInputStream file6 = new FileInputStream(keyPath);
    ObjectInputStream read1 = new ObjectInputStream(file6);
    int[] key1 = (int[]) read1.readObject();
    ko.decryption_logic(cipher1, key1);
    break;

   default:
    break;
   }
  } catch (Exception e) {
   e.printStackTrace();
  }
 }
}