The java.util.HashMap sets the initial capacity to the smallest power of
2 greater than or equal to the supplied initialCapacity.
Thus if an initialCapacity of 0 is provided, then the initial capacity
will be 1.
Therefore, it is consistent with java.util.HashMap to accept an argument
of zero for initialCapacity but in fact have an initial capacity of one.
Paul Wolfgang
On 3/12/2011 1:30 PM, Jochen Wiedmann (JIRA) wrote:
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https://issues.apache.org/jira/browse/COLLECTIONS-323?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13006073#comment-13006073
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Jochen Wiedmann commented on COLLECTIONS-323:
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Quoting from the initial bug report: "This is inconsistent with the standard Java
HashMap constructor HashMap(int initialCapacity),"
I had to choose between consistency (incrementing the size by one) and the
current behaviour. The latter made much more sense to me and I can think of no
reason why one would intentionally create an LRUMap of size 0. The
IllegalArgumentException makes perfect sense to me.
Behavior of constructors CaseInsensitiveMap inconsistent with standard Java
HashMap
-----------------------------------------------------------------------------------
Key: COLLECTIONS-323
URL: https://issues.apache.org/jira/browse/COLLECTIONS-323
Project: Commons Collections
Issue Type: Bug
Components: Map
Affects Versions: 3.2
Environment: Any
Reporter: Maarten Brak
Assignee: Jochen Wiedmann
Priority: Minor
Fix For: 3.2.2
Attachments: patch.tar.gz
Original Estimate: 24h
Remaining Estimate: 24h
The constructor CaseInsensitiveMap(int initialCapacity) throws an IllegalArgumentException if
"the initial capacity is less than one". This is inconsistent with the standard Java
HashMap constructor HashMap(int initialCapacity), which throws an if IllegalArgumentException if
"the initial capacity is negative".
Thus:
new HashMap(0) ==> no exception
new CaseInsensitiveMap(0) ==> IllegalArgumentException.
This inconsistency is confusing.
Actions:
- Change Javadoc (this shouldn't be a problem in practice since surely there is
no code around depending on the fact that the constructor throws an
IllegalArgumentException :-))
- Change code.
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