[COLLECTIONS-389] Inconsistent Javadoc comment and code for mapTransformer(Map<? super I, ? extends O>) in org.apache.commons.collections.TransformerUtils

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.0, 4.x
• Fix Version/s: 4.0-alpha1, 4.0
• Component/s: Collection
• Labels: javadoc null

Environment

Platform Independent

• Assignee: Unassigned
• Reporter: SHIN HWEI TAN
• Created: 08/Jan/12 08:31
• Updated: 09/Nov/14 14:31
• Resolved: 09/Apr/12 17:21

Description

The Javadoc comment below states that the method "throws IllegalArgumentException if the map is null":
/**
....

• @param map the map to use to transform the objects
• @return the transformer
• @throws IllegalArgumentException if the map is null
  */
  public static <I, O> Transformer<I, O> mapTransformer(Map<? super I, ? extends O> map) { return MapTransformer.mapTransformer(map); }

  However, the method returns a NULL_INSTANCE object instead of throwing IllegalArgumentException when called with null.

Suggested Fixes:
1. Change "@throws IllegalArgumentException if the map is null" and "@return" to "@return NULL_INSTANCE if the map is null".
or
2. Remove the entire "throws IllegalArgumentException if the map is null".