title: why's this program giving a runtime error on jcreator but not on netbeans?
body: <p>This is my solution for sphere's online judge <a href="https://www.spoj.pl/problems/PALIN/" rel="nofollow noreferrer">palin problem</a>. It runs fine on Netbeans, but the judge is rejecting my answer saying it gives a RuntimeError. I tried it on JCreator and it says:</p>
  
  <pre><code>Exception in thread "main" java.lang.NumberFormatException: For input string: ""
      at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
      at java.lang.Integer.parseInt(Integer.java:468)
      at java.lang.Integer.parseInt(Integer.java:497)
      at Main.main(Main.java:73)
  </code></pre>
  
  <p>I'm not passing an empty string for it to parse, why is this?</p>
  
  <p>The code:</p>
  
  <pre><code>import java.io.*;
  import java.util.*;
  
  
  
  class Main {
  
      public static int firstPalinLargerThanNum(int num){
  
          int foundPalin =0;
  
          int evalThisNum = ++num;
  
          while (true){
  
  
          if (isPalin(evalThisNum))
  
  
              break;
  
          evalThisNum++;
          }
  
          foundPalin = evalThisNum;
          return foundPalin;
  
      }
  
      public static boolean isPalin(int evalThisNum){
  
             boolean isItPalin = false;
  
             int dig=0;
             int rev=0;
  
  
            int  n = evalThisNum;
  
            while (evalThisNum &gt; 0)
            {
  
             dig = evalThisNum % 10;
             rev = rev * 10 + dig;
             evalThisNum = evalThisNum / 10;
  
            }
  
             if (n == rev) {
  
                 isItPalin=true;
             }
  
             return isItPalin;
  
      }
  
  
      public static void main(String args[]) throws java.lang.Exception{
  
          BufferedReader r1 = new BufferedReader(new InputStreamReader(System.in));
  
          /*BufferedReader r1 = new BufferedReader (new FileReader(new File ("C:\\Documents and Settings\\Administrator\\My Documents\\NetBeansProjects\\Sphere\\src\\sphere\\sphere\\PALIN_INPUT.txt")));*/
  
          String read = r1.readLine();
  
          int numberOfTestCases = Integer.parseInt(read);
  
          for (int i=0; i&lt;numberOfTestCases;i++){
  
          read = r1.readLine();
  
          if (read!=null){
  
          int num = Integer.parseInt(read);
  
          System.out.println(firstPalinLargerThanNum(num));
  
          }
          }
      }
  
  
  }
  </code></pre>
  
  <p>Input:</p>
  
  <pre><code>2
  808
  2133
  </code></pre>
  
  <p>line 73 is:         <code>int num = Integer.parseInt(read);</code></p>