Hi Joe,
On 20/06/2012 11:28 AM, Joe Darcy wrote:
On 6/19/2012 6:14 PM, David Holmes wrote:
On 19/06/2012 10:27 PM, maurizio.cimadam...@oracle.com wrote:
Changeset: 34e254ffd0e7
Author: mcimadamore
Date: 2012-06-19 13:25 +0100
URL: http://hg.openjdk.java.net/jdk8/tl/langtools/rev/34e254ffd0e7
7177701: error: Filling jar message during
javax/imageio/metadata/IIOMetadataFormatImpl compilation
Summary: Recent JDK hash changes affected order in which files are
returned from JavacFileManager.list()
Reviewed-by: jjg
! src/share/classes/com/sun/tools/javac/file/ZipFileIndex.java
That change seems fragile to say the least. Somewhere some piece of
code depends on the iteration order of the collection. The recent
changes meant that HashSet's returned order changed and broke things.
So you change to a LinkedHashSet which somehow restores the old order
(or at least reorders it yet again but in a way that doesn't cause a
problem).
David
LinkedHashSet is specified to preserve insertion order in iteration:
"This implementation [of LinkedHashSet] differs from HashSet in that it
maintains a doubly-linked list running through all of its entries. This
linked list defines the iteration ordering, which is the order in which
elements were inserted into the set (insertion-order)."
Therefore, LinkedHashSet is just the right class to use when predictable
iteration order matters :-)
So is there an assumption that traversal is in insertion order? Or is it
just that insertion order happens to work?
David
-Joe
