Java Common Collection Selection guide

Java collection in the selection of the time should choose that appropriate? A table that tells you how to choose a Java collection

	Java collection classes	is thread safe	Whether the key value pair	Sort	Performance	Whether the element can be duplicated	Scaling strategy
List interface	ArrayList	Whether	Whether	Maintain the order of the time	High query performance, and the performance of adding and deleting elements is low	Is	1.5 times-fold expansion with an element greater than 100% of the current capacity
	LinkedList	Whether	Whether	Have order	Low query performance, and high performance of elements and additions	Is
	Vector	Is	Whether	Have order	Low	Is
	Stack	Is	Whether	Have order, advanced after out	Low	Is
Map interface	HashMap	Whether	Is	Not sorted	Quick Insert and find	Key cannot be duplicated, value can be duplicated	Twice-fold expansion with an element greater than 75% of the current capacity
	Hashtable	Is	Is	Not sorted	Low	Key cannot be duplicated, value can be duplicated
	TreeMap	Whether	Is	Auto Sort by key	Quick Insert and find	Key cannot be duplicated, value can be duplicated
Set interface	HashSet	Whether	Whether	Not sorted	Quick Insert and find	Whether
	TreeSet	Whether	Whether	Default ascending sort (return value by compare to interface)	Quick Insert and find	Whether

User guide:

1 in the case of the set scenario, specify the initialization capacity, because the capacity is not specified, the initial capacity is 10, each expansion will be a copy of the underlying array, consumption performance;

2 All sets the underlying storage is an array, the array can hold the base type, and the collection can only save objects

The 3 Java.lang.reflect.Array tool provides an array of operations; The Java.util.collection tool provides a collection of operations

4 HashMap can be synchronized with map M = Collections.synchronizedmap (HASHMAP)

Java Common Collection Selection guide