Sun has a (now unsupported) download of their collections classes that were added for JDK 1.2 that are 1.1 compatible. You can download them from the old Infobus web page. At the bottom of the page is a link to the JDK1.1 Collections package which is (from the readme):
This package was mechanically constructed from the JDK1.2 source for
the Collections API's using a sed script to substitute the new
package name (com.sun.java.util.collections) for the existing JDK1.2
package name(s) (java.util and java.lang). Therefoe they are bug for
bug compatible!!!
Classes included (just .class files, of course):
java.util.AbstractCollection
java.util.AbstractList
java.util.AbstractMap
java.util.AbstractSequentialList
java.util.AbstractSet
java.util.ArrayList
java.util.Arrays
java.util.Collection
java.util.Collections
java.util.Comparator
java.util.ConcurrentModificationException
java.util.HashMap
java.util.HashSet
java.util.Hashtable
java.util.Iterator
java.util.LinkedList
java.util.List
java.util.ListIterator
java.util.Map
java.util.NoSuchElementException
java.util.Random
java.util.Set
java.util.SortedMap
java.util.SortedSet
java.util.TreeMap
java.util.TreeSet
java.util.Vector
java.lang.Comparable
java.lang.UnsupportedOperationException
... although they are repackaged under com.sun.java.util.collections.
tags: ComputersAndTechnology
