Java SE Collections

The Java SE Collections exam covers collection classes from the java.util package, including some from the .concurrent sub-package.

You'll need a strong knowledge of Iterators, Collections and Maps, and sorting, converting and copying them. Java 5 new features concerning collections are covered.

Prerequisites: We recommend that you first complete the Java SE - Basic and Java SE Core - Intermed exams.

Generics are covered in a specific sub-category, but questions in other categories can also use generics which is considered as a core feature, used in the signature of many methods of the API.

	Released	Beta	Frozen
Interfaces 2 questions Write code that uses the Collections interfaces (Collection, Set, List, Queue, Map, SortedSet and SortedMap) including their bulk operation methods and array operation methods, such as containsAll(), addAll(), retainAll(), toArray(), etc.	105	238	122	Add a question Beta questions
Implementation
General-purpose Implementations 3 questions Write code that use the classic implementation of Collections. Set interface : HashSet, TreeSet, LinkedHashSet List interface : ArrayList, LinkedList, Vector Map interface : HashMap, TreeMap, LinkedHashMap, Hashtable Queue interface : PriorityQueue	78	780	178	Add a question Beta questions
Special-purpose Implementations 2 questions Identify cases where the usage of these classes is appropriate, and write code that use them. Set interface : EnumSet, CopyOnWriteArraySet List interface : CopyOnWriteArrayList Map interface : EnumMap, WeakHashMap, IdentityHashMap	18	10	86	Add a question Beta questions
Wrapper Implementations 2 questions Produce wrapper implementations from the Collections class, and identify their behaviours: synchronization wrappers, unmodifiable wrappers and checked wrappers.	7	0	35	Add a question Beta questions
Convenience Implementations 2 questions Write code that use the following methods appropriately: Arrays.asList, Collections.nCopies, Collections.singleton.. and Collections.empty..	23	0	64	Add a question Beta questions
Custom Collection Implementations 2 questions Identify abstract collection classes, and extend them to create custom collection classes: AbstractCollection, AbstractList, AbstractSet, AbstractSequentialList, AbstractQueue, AbstractMap.	2	0	23	Add a question Beta questions
Ordering 2 questions Sort collections and arrays (natural and non natural orders) using the sort method of the classes Collections and Arrays. Implement the Comparable and Comparator interfaces to customize sorting. Identify cases when a ClassCastException is thrown during sorting. Develop code using Collections.binarySearch, Arrays.binarySearch. Develop code using the finding and ordering methods from the Collections class: min, max, reverse, reverseOrder, rotate, shuffle and swap.	39	7	121	Add a question Beta questions
Misc Manipulations Collections class, Arrays class and bit twiddling.
Collections class 1 question Write code that makes appropriate use of these Collections class methods: addAll, copy, disjoint, enumeration, fill, frequency, indexOfSubList, lastIndexOfSubList, List and replaceAll. Methods not covered here: binarySearch, min, max, reverse, rotate, shuffle, sort, swap (Ordering category), empty.., nCopies, singleton.. (Convenience Implementations category). This category also excludes the synchronization, unmodifiable and checked wrappers (Wrapper Implementation).	22	59	58	Add a question Beta questions
Arrays class 1 question Write code that makes appropriate use of the Arrays class methods containing the words equals, hashCode, fill and toString. Methods not covered here: asList (Convenience Implementations category), sort and binarySearch (Ordering category).	19	0	43	Add a question Beta questions
Bit Twiddling 1 question Use the bit manipulation methods (that start with reverse, rotate and bitCount), from the Long and Integer classes. Not covered: other methods of the Long and Integer classes.	1	0	24	Add a question Beta questions