HashSet implementation principle?
Set interface detailed analysis:
the Java container --Set Interface Analysis
(1) HashSet is a class that implements the Set interface.
(2) the underlying implemented using HashMap (array + chain). The object is stored in the HashMap key value, the key may be utilized HashMap unrepeatable characteristics HashSet to ensure that no duplicate data object. Wherein the target value the value stored in unity: private static final Object PRESENT = new Object ().
(3) random, non-repeatable. Element allows the collection is null.
HashSet specific analysis and simulation codes to achieve its underlying principles, the first visible text links.
