A RSA System in Java

import java.util.Arrays;
int e;
int P; //factorial P
int Q; // factorial Q
int PQ; //multiplication of PQ
int PQ1; //multiplication of (P-1)(Q-1)
int numberMessage;
int theD;
int z;
int[] possibleE = new int[50];
void setE() {
  for(int a = 0; a < 50; a++){
   possibleE[a] = 2 + a;  
  }
}
public void draw() {
  noLoop();
  P = round(random(50))+ 508; //random number
  Q = round(random(50))+ 518; //random number
  setE();
  //println(e);
  PQ = P*Q;
  PQ1 = (P-1)*(Q-1);
  int[] factors = new int[1000];
  int numberOfFactors = 0;
  for(int zz = 2; zz < PQ1; zz++){
   if(PQ1%zz == 0){
     factors[0] = zz;
   }
  }
  int currentEPosition = 0;
  e = possibleE[currentEPosition];
  for(int p = 0; p < factors.length; p++){
    if(e == factors[p] && currentEPosition<50){
     currentEPosition++;
     e = possibleE[currentEPosition];
     p = 0;
    }
  }  
  //share E and PQ

  //Alice calculations
  String message = "abc";
  String charUp = " ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  String charDown = " abcdefghijklmnopqrstuvwxyz";
  char[] charactersUpper = charUp.toCharArray();
  char[] charactersLower = charDown.toCharArray();
  String[] numberTemp = split("00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26", ' ');
  int[] numberCode = new int[27];
  for (int i = 0; i < numberTemp.length; i++) {
    numberCode[i] = Integer.parseInt(numberTemp[i]);
  }
  char[] charMessage = message.toCharArray();//split the message into individual characters
  int[] messageCode = new int[message.length()];
  for (int i = 0; i < charMessage.length; i++) { //convert text to a number
    for (int j = 0; j < charactersUpper.length; j++) {
      println(charactersUpper[j]);
      if (charMessage[i] == charactersUpper[j] || charMessage[i] == charactersLower[j]) {
        messageCode[i] = numberCode[j];
        println(numberCode[j]);
      }
    }
  }
  String StringNumberMessage = Arrays.toString(messageCode);
  StringNumberMessage = StringNumberMessage.replace(",", "");
  StringNumberMessage = StringNumberMessage.replace(" ", "");
  StringNumberMessage = StringNumberMessage.replace("[", "");
  StringNumberMessage = StringNumberMessage.replace("]", "");
  numberMessage = Integer.parseInt(StringNumberMessage);
  println(numberMessage);
  int codedMessage = encrypt();
  println(codedMessage + " !!!!!");
  //bob decrypt message

  while ( (e*z)%PQ1 != 1) {
    println((e*z)%PQ1);
    z++;
  }
  theD = z;
  println(theD + "BJHBJEB");
  int uncodedMessage = decrypt(codedMessage);
  println("d = " + theD + " PQ: " + PQ + "the message:" + codedMessage);
  println("e = " + e + " PQ: " + PQ + "the message:" + numberMessage);
 
}

int encrypt() {
  int b = round(numberMessage/2);
  println(b);
  int c = numberMessage%2;
  println(c);
  int d = round(pow(e, 2))%PQ;
  println(d);
  int v = round(pow(d, b));
  println(v);
  int f = (c*e);
  println(f);
  int a;
  if (f != 0) {
    a = f*v;
    println("wee");
  }
  else {
    a = v;
    println("wherp");
  }
  println(e);
  println(a);
  println(PQ);
  int g = a%PQ;
  println(g);
  return g;
}
int decrypt(int codedMessage) {
  int b = round(theD/2);
  println(b);
  int c = theD%2;
  int d = round(pow(codedMessage, 2))%PQ;
  println(d);
  int v = round(pow(d, b));
  println(v);
  int f = (c*codedMessage);
  int a;
  if (f != 0) {
    a = f*v;
    println("wee");
  }
  else {
    a = v;
    println("wherp");
  }
  int g = a%PQ;
  println(g);
  return g;
}