Re: Strange JTable issue in Sun's Java code

I get:
java.lang.NegativeArraySizeException
    at NullTest.removeEntries(NullTest.java:43)
when I run this.
Maybe another precondition needs checking.

public class Test {

   private static int[] a = {};

   public static void main(String[] args) {

     try {
       removeEntries(0,3);
     } catch (Exception e) {
       e.printStackTrace();
     }

   }

   private static int[] getSizes() {
     return new int[]{1,2,3,4,5};
   }

   /**
    * Removes a contiguous group of entries
    * from this <code>SizeSequence</code>.
    * Note that the values of <code>start</code> and
    * <code>length</code> must satisfy the following
    * conditions: <code>(0 <= start < getSizes().length)
    * AND (length >= 0)</code>. If these conditions are
    * not met, the behavior is unspecified and an exception
    * may be thrown.
    *
    * @param start the index of the first entry to be removed
    * @param length the number of entries to be removed
    */
   public static void removeEntries(int start, int length) {
     assert getSizes() != null;
     assert 0 <= start;
     assert start < getSizes().length;
     assert length >= 0;
     assert a != null;
     int sizes[] = getSizes();
     //int end = start + length;
     int n = a.length - length;
     a = new int[n];
     for (int i = 0; i < start; i++) {
         a[i] = sizes[i] ;
     }
     for (int i = start; i < n; i++) {
         a[i] = sizes[i+length] ;
     }
     //setSizes(a);
}