On second thought, review of the JDK Hashtable source code points out
that my suggested fix modifies the behavior of Hashtable's keySet()
method. Hashtable's implementation manages to return a sychronized
reference to its Set of keys via some java.util.Collections
machinations. The proper fix here is to simply remove
SequencedHashtable's values() method over-ride, and to add yourself to
the author's list. ;)
Dan
Daniel Rall <[EMAIL PROTECTED]> writes:
> Hi Henning, you're quite right that this is a bug--thanks for the
> detailed description and sample code. :)
>
> The existing values() method should be removed (an implementation of
> it already exists in Hashtable), and a cheaper method which is in line
> with the existing java.util.Map interface:
>
> public Set keySet()
> {
> return new HashSet(keySequence);
> }
>
> You'll need to import HashSet.
>
>
> "Henning P. Schmiedehausen" <[EMAIL PROTECTED]> writes:
>
> > Index: SequencedHashtable.java
> > ===================================================================
> > RCS file:
>/home/cvspublic/jakarta-turbine/src/java/org/apache/turbine/util/SequencedHashtable.java,v
> > retrieving revision 1.4
> > diff -u -r1.4 SequencedHashtable.java
> > --- SequencedHashtable.java 2001/05/20 02:38:52 1.4
> > +++ SequencedHashtable.java 2001/06/01 14:18:09
> > @@ -57,6 +57,7 @@
> > import java.util.Collection;
> > import java.util.Hashtable;
> > import java.util.Iterator;
> > +import java.util.List;
> > import java.util.LinkedList;
> > import java.util.Map;
> > import java.util.Set;
> > @@ -73,6 +74,7 @@
> > * the use of a list of <code>Map.Entry</code> objects.
> > *
> > * @author <a href="mailto:[EMAIL PROTECTED]";>Daniel Rall</a>
> > + * @author <a href="mailto:[EMAIL PROTECTED]";>Henning P. Schmiedehausen</a>
> > * @version $Id: SequencedHashtable.java,v 1.4 2001/05/20 02:38:52 dlr Exp $
> > */
> > public class SequencedHashtable extends Hashtable
> > @@ -261,10 +263,14 @@
> > }
> >
> > /**
> > - * Slightly cheaper implementation of <code>values()</code> method.
> > + * Returns the keys in the table as a List.
> > + *
> > + * @return List of all keys
> > */
> > - public Collection values ()
> > +
> > + public List keyList()
> > {
> > return keySequence;
> > }
> > +
> > }
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