Name: ksC84122 Date: 03/26/99


Arrays.sort(Object[] a, int fromIndex, int toIndex, Comparator c) does not throw NullPointerException
when Comparator parameter is null and array is valid. However Arrays.sort(Object[] a, Comparator c)
throws NullPointerException under the same conditions.

Javadoc says nothing about handling Comparator null values, but obviously Comparator instance is needed
to define result of sorting.

Here is example to reproduce this:

------------------------------ Test2.java -------------------------------------

import java.util.Arrays;
import java.util.Comparator;

public class Test2 {
    public static void main(String argv[]) {
        Object[] a = {"1", "2"};
        int fromIndex = 0;
        int toIndex = 1;
        Comparator c = null;
        try {
            Arrays.sort(a, c);
        } catch (NullPointerException npe1) {
            System.out.println("OKAY: Arrays.sort(Object[], Comparator) throws" +
                               " NullPointerException when Comparator is null");
        }
        try {
            Arrays.sort(a, fromIndex, toIndex, c);
            System.out.println("Failed: No exceptions has been thrown by" +
                           " Arrays.sort(Object[], int, int, Comparator)" +
                           " when Comparator is null");
        } catch (NullPointerException npe2) {
            System.out.println("OKAY: Arrays.sort(Object, int, int, Comparator)" +
                               " throws NullPointerException" +
                               " when Comparator is null");
        }
        return;
    }
}

--------------- Sample run (JDK-1.2.1-L) ---------------

<kai@moon(pts/6).260> java Test2
OKAY: Arrays.sort(Object[], Comparator) throws NullPointerException when Comparator is null
Failed: No exceptions has been thrown by Arrays.sort(Object[], int, int, Comparator) when Comparator is null

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