Java Coding Problems

Thread-safe set

The thread-safe version of a Set is CopyOnWriteArraySet. The following table enumerates the Java built-in single-threaded and multithreaded sets:

Single thread	Multithreaded
HashSet TreeSet (sorted set) LinkedHashSet (maintain insertions order) BitSet EnumSet	ConcurrentSkipListSet (sorted set) CopyOnWriteArraySet (often reads, seldom updates)

This is a Set that uses an internal CopyOnWriteArrayList for all of its operations. Creating such a Set can be done as follows:

Set<Integer> set = new CopyOnWriteArraySet<>();

Use this collection when reads are frequent and changes are seldom.

The thread-safe version of NavigableSet is ConcurrentSkipListSet (concurrent SortedSet implementation, with most basic operations ...