Class TreeList<E>
- Type Parameters:
E- the type of the elements in the list.
- All Implemented Interfaces:
Iterable<E>,Collection<E>,List<E>
List implementation that is optimized for fast insertions and
removals at any index in the list.
This list implementation utilises a tree structure internally to ensure that
all insertions and removals are O(log n). This provides much faster performance
than both an ArrayList and a LinkedList where elements
are inserted and removed repeatedly from anywhere in the list.
The following relative performance statistics are indicative of this class:
get add insert iterate remove
TreeList 3 5 1 2 1
ArrayList 1 1 40 1 40
LinkedList 5800 1 350 2 325
ArrayList is a good general purpose list implementation.
It is faster than TreeList for most operations except inserting
and removing in the middle of the list. ArrayList also uses less
memory as TreeList uses one object per entry.
LinkedList is rarely a good choice of implementation.
TreeList is almost always a good replacement for it, although it
does use slightly more memory.
- Since:
- 3.1
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Field Summary
Fields inherited from class java.util.AbstractList
modCount -
Constructor Summary
ConstructorsConstructorDescriptionTreeList()Constructs a new empty list.TreeList(Collection<? extends E> coll) Constructs a new empty list that copies the specified collection. -
Method Summary
Modifier and TypeMethodDescriptionvoidAdds a new element to the list.booleanaddAll(Collection<? extends E> c) Appends all the elements in the specified collection to the end of this list, in the order that they are returned by the specified collection's Iterator.voidclear()Clears the list, removing all entries.booleanSearches for the presence of an object in the list.get(int index) Gets the element at the specified index.intSearches for the index of an object in the list.iterator()Gets an iterator over the list.Gets a ListIterator over the list.listIterator(int fromIndex) Gets a ListIterator over the list.remove(int index) Removes the element at the specified index.Sets the element at the specified index.intsize()Gets the current size of the list.Object[]toArray()Converts the list into an array.Methods inherited from class java.util.AbstractList
add, addAll, equals, hashCode, lastIndexOf, removeRange, subListMethods inherited from class java.util.AbstractCollection
containsAll, isEmpty, remove, removeAll, retainAll, toArray, toStringMethods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, waitMethods inherited from interface java.util.Collection
parallelStream, removeIf, streamMethods inherited from interface java.util.List
containsAll, isEmpty, remove, removeAll, replaceAll, retainAll, sort, spliterator, toArray
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Constructor Details
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TreeList
public TreeList()Constructs a new empty list. -
TreeList
Constructs a new empty list that copies the specified collection.- Parameters:
coll- the collection to copy- Throws:
NullPointerException- if the collection is null
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Method Details
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add
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addAll
Appends all the elements in the specified collection to the end of this list, in the order that they are returned by the specified collection's Iterator.This method runs in O(n + log m) time, where m is the size of this list and n is the size of
c.- Specified by:
addAllin interfaceCollection<E>- Specified by:
addAllin interfaceList<E>- Overrides:
addAllin classAbstractCollection<E>- Parameters:
c- the collection to be added to this list- Returns:
trueif this list changed as a result of the call- Throws:
NullPointerException- if the specified collection contains a null element and this collection does not permit null elements, or if the specified collection is null
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clear
Clears the list, removing all entries.- Specified by:
clearin interfaceCollection<E>- Specified by:
clearin interfaceList<E>- Overrides:
clearin classAbstractList<E>
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contains
Searches for the presence of an object in the list.- Specified by:
containsin interfaceCollection<E>- Specified by:
containsin interfaceList<E>- Overrides:
containsin classAbstractCollection<E>- Parameters:
object- the object to check- Returns:
- true if the object is found
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get
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indexOf
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iterator
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listIterator
Gets a ListIterator over the list.- Specified by:
listIteratorin interfaceList<E>- Overrides:
listIteratorin classAbstractList<E>- Returns:
- the new iterator
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listIterator
Gets a ListIterator over the list.- Specified by:
listIteratorin interfaceList<E>- Overrides:
listIteratorin classAbstractList<E>- Parameters:
fromIndex- the index to start from- Returns:
- the new iterator
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remove
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set
Sets the element at the specified index.- Specified by:
setin interfaceList<E>- Overrides:
setin classAbstractList<E>- Parameters:
index- the index to setobj- the object to store at the specified index- Returns:
- the previous object at that index
- Throws:
IndexOutOfBoundsException- if the index is invalid
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size
Gets the current size of the list.- Specified by:
sizein interfaceCollection<E>- Specified by:
sizein interfaceList<E>- Specified by:
sizein classAbstractCollection<E>- Returns:
- the current size
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toArray
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