Java iPad compiler issue

[MightyKing]

Hello all, It's my first time in these forums and I have no idea as to where i should post this, so I figured might as well here.

Anyways let's get down to business.

I've downloaded a compiler app for java for my ipad Java Programming Language - iOS app from Yauheni Shauchenka | Appolicious ™ iPhone and iPad App Directory and I've been getting some issues that don't happen in a compiler for a PC. For example apparently I can't have a program that asks the user to input information such as names, numbers, etc. here is the code of the program I'm currently trying out :

import java.io.*;
import java.util.*;
public class Main{
public static BufferedReader var=new BufferedReader(new InputStreamReader(System.in));
public static void main(String []arg)throws Exception{

      String cadena1;
      String cadena2;
      String sub1;
      String sub2; 
      String sub3;
      String sub4; 
      String sub5;
      String sub6;

     System.out.println("Escribe tu nombre (Primer Nombre, Apellido Paterno y Apellido Materno) "); //. first and last names
      cadena1=var.readLine();
     System.out.println("Escribe el dia que naciste en el formato dd/mm/aaaa "); // date of birth DD/MM/YYYY
      cadena2=var.readLine();

      StringTokenizer token1;
      token1=new StringTokenizer(cadena1," ");
      String cad1=token1.nextToken();
      String cad2=token1.nextToken();
      String cad3=token1.nextToken();

      StringTokenizer token2;
      token2=new StringTokenizer(cadena2,"/");
      String cad4=token2.nextToken();
      String cad5=token2.nextToken();
      String cad6=token2.nextToken();

      sub1=cad1.substring(0,1);
      sub2=cad2.substring(0,2);
      sub3=cad3.substring(0,1);
      sub4=cad4.substring(0,2);
      sub5=cad5.substring(0,2);
      sub6=cad6.substring(2,4);

     System.out.println("Tu RFC es " + sub2 + sub3 + sub1 + sub6 + sub5 + sub4); // RFC = latin american document

 }
}

And the erros I took screenshots of are:



I took the liberty of translating parts of the code that were in spanish to english in comments.

I should point out that this program works 100% in my netbeans compiler on my PC. I've also compiled and ran various simple programs in this app for the ipad, and no issues there. However I've encountered issues on programs that require the user's input.

Here are the screenshots of how my code looks in the actual app:





Anyways, any ideas or clues as how to fix the specific issue of this code? Or better yet, can this app actually compile and run programs which require user input?

Thank you for reading.

[DarrylBurke]

here is the code of the program I'm currently trying out :

import java.io.*;
import java.util.*;
public class Main{
public static BufferedReader var=new BufferedReader(new InputStreamReader(System.in));
public static void main(String []arg)throws Exception{

* * String cadena1;
* * String cadena2;
* * String sub1;
* * String sub2; * *
* * String sub3;
* * String sub4; * *
* * String sub5;
* * String sub6; * *
* * * * * * * **
* * System.out.println("Escribe tu nombre (Primer Nombre, Apellido Paterno y Apellido Materno) "); //. first and last names
* * cadena1=var.readLine();
* * System.out.println("Escribe el dia que naciste en el formato dd/mm/aaaa "); // date of birth DD/MM/YYYY
* * cadena2=var.readLine();
* **
* * StringTokenizer token1;
* * token1=new StringTokenizer(cadena1," ");
* * String cad1=token1.nextToken();
* * String cad2=token1.nextToken();
* * String cad3=token1.nextToken();
* **
* * StringTokenizer token2;
* * token2=new StringTokenizer(cadena2,"/");
* * String cad4=token2.nextToken();
* * String cad5=token2.nextToken();
* * String cad6=token2.nextToken();
* **
* * sub1=cad1.substring(0,1);
* * sub2=cad2.substring(0,2);
* * sub3=cad3.substring(0,1);
* * sub4=cad4.substring(0,2);
* * sub5=cad5.substring(0,2);
* * sub6=cad6.substring(2,4);
* **
* * System.out.println("Tu RFC es " + sub2 + sub3 + sub1 + sub6 + sub5 + sub4); // RFC = latin american document
* **
* * }
}

Don't be silly, you can't even compile that code with all the asterisks.

db

[MightyKing]

Don't be silly, you can't even compile that code with all the asterisks.

db

Sorry I thought that was a no brainer, the asterisks were placed there after adding the [ CODE][/CODE] parameters in the post. No real asterisks are there in the actual code.. That's exactly the reason I posted the screenshots of the actual code in the app in the first place. Allow me to do so again.

This is how the real code looks in the compiler:





Thank you.

[Tolls]

Can you copy and paste the errors instead of putting up screenshots...they're a pain.

[MightyKing]

Can you copy and paste the errors instead of putting up screenshots...they're a pain.

Exception in thread "main" java.lang.NullPointerException
	at java.util.StringTokenizer.<init>(StringTokenizer.java:182)
	at java.util.StringTokenizer.<init>(StringTokenizer.java:204)
	at Main.main(Main.java:22)

[Tolls]

And which line is line 22 (again paste it in)?
What is null on that line?

[MightyKing]

And which line is line 22 (again paste it in)?
What is null on that line?

I had already done that if you read the first post. Anyways here it is again...

import java.io.*;
import java.util.*;
public class Main{
public static BufferedReader var=new BufferedReader(new InputStreamReader(System.in));
public static void main(String []arg)throws Exception{
 
      String cadena1;
      String cadena2;
      String sub1;
      String sub2;
      String sub3;
      String sub4;
      String sub5;
      String sub6;
 
     System.out.println("Escribe tu nombre (Primer Nombre, Apellido Paterno y Apellido Materno) "); //. first and last names
      cadena1=var.readLine();
     System.out.println("Escribe el dia que naciste en el formato dd/mm/aaaa "); // date of birth DD/MM/YYYY
      cadena2=var.readLine();
 
      StringTokenizer token1;
      token1=new StringTokenizer(cadena1," ");
      String cad1=token1.nextToken();
      String cad2=token1.nextToken();
      String cad3=token1.nextToken();
 
      StringTokenizer token2;
      token2=new StringTokenizer(cadena2,"/");
      String cad4=token2.nextToken();
      String cad5=token2.nextToken();
      String cad6=token2.nextToken();
 
      sub1=cad1.substring(0,1);
      sub2=cad2.substring(0,2);
      sub3=cad3.substring(0,1);
      sub4=cad4.substring(0,2);
      sub5=cad5.substring(0,2);
      sub6=cad6.substring(2,4);
 
     System.out.println("Tu RFC es " + sub2 + sub3 + sub1 + sub6 + sub5 + sub4); // RFC = latin american document
 
 }
}

[Tolls]

Except many people don't print their entire code here so the line numbers rarely match.
Consequently I try not to waste my time looking at lines that may well turn out not to be the ones causing the problem.

Add a println prior to the creation of the tokeniser to print out what cadena1 is.
It seems to think it's null at this point.

readLine() will only return null if end of stream is encountered, which it shouldn't do in this case (though who knows with an iPad). It could well be a bug in the JVM/SDK you're forced to use.