Name: jl125535 Date: 03/23/2004


FULL PRODUCT VERSION :
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_02-b03)
Java HotSpot(TM) Client VM (build 1.4.2_02-b03, mixed mode)

java version "1.5.0-beta2"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-beta2-b43)
Java HotSpot(TM) Client VM (build 1.5.0-beta2-b43, mixed mode)

A DESCRIPTION OF THE PROBLEM :
The Javadoc for TreeSet.contains() at http://java.sun.com/j2se/1.5.0/docs/api/java/util/TreeSet.html#contains(java.lang.Object) does not specify that it will throw a NullPointerException under any circumstances.

When TreeSet.contains() is called with a null parameter and the set is empty, false is returned.

When TreeSet.contains() is called with a null parameter and the set is not empty, a NullPointerException is thrown.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1) instantiate a TreeSet
2) add an element to the TreeSet
3) call TreeSet.contains(null)

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
false should be returned if the set does not contain null, true if it does
ACTUAL -
NullPointerException thrown

ERROR MESSAGES/STACK TRACES THAT OCCUR :
Exception in thread "main" java.lang.NullPointerException
        at java.util.TreeMap.compare(TreeMap.java:1085)
        at java.util.TreeMap.getEntry(TreeMap.java:345)
        at java.util.TreeMap.containsKey(TreeMap.java:203)
        at java.util.TreeSet.contains(TreeSet.java:195)
        at Test.main(Test.java:10)


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.TreeSet;

public class Test
{
    public static void main(String[] args)
    {
        TreeSet s = new TreeSet();
        System.out.println(s.contains(null));
        s.add(new Object());
        System.out.println(s.contains(null));
    }
}

---------- END SOURCE ----------
(Incident Review ID: 244101)
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