Package com.aspectran.core.util
Class ArrayStack<E>
- java.lang.Object
-
- java.util.AbstractCollection<E>
-
- java.util.AbstractList<E>
-
- java.util.ArrayList<E>
-
- com.aspectran.core.util.ArrayStack<E>
-
- Type Parameters:
E
- the type of elements in this list
- All Implemented Interfaces:
java.io.Serializable
,java.lang.Cloneable
,java.lang.Iterable<E>
,java.util.Collection<E>
,java.util.List<E>
,java.util.RandomAccess
public class ArrayStack<E> extends java.util.ArrayList<E>
This class is a clone of org.apache.commons.collections4.ArrayStack
An implementation of theStack
API that is based on anArrayList
instead of aVector
, so it is not synchronized to protect against multi-threaded access. The implementation is therefore operates faster in environments where you do not need to worry about multiple thread contention.The removal order of an
ArrayStack
is based on insertion order: The most recently added element is removed first. The iteration order is not the same as the removal order. The iterator returns elements from the bottom up, whereas thepop()
method removes them from the top down.Unlike
Stack
,ArrayStack
accepts null entries.- See Also:
Stack
, Serialized Form
-
-
Constructor Summary
Constructors Constructor Description ArrayStack()
Constructs a new emptyArrayStack
.ArrayStack(int initialSize)
Constructs a new emptyArrayStack
with an initial size.
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description E
peek()
Returns the top item off of this stack without removing it.E
peek(int n)
Returns the n'th item down (zero-relative) from the top of this stack without removing it.E
peek(java.lang.Class<?> target)
E
pop()
Pops the top item off of this stack and return it.E
push(E item)
Pushes a new item onto the top of this stack.int
search(E object)
Returns the one-based position of the distance from the top that the specified object exists on this stack, where the top-most element is considered to be at distance1
.E
update(int n, E item)
Replaces the n'th item down (zero-relative) from the top of this stack with another item without removing it.E
update(E item)
Replaces the top item of this stack with another item without removing it.-
Methods inherited from class java.util.ArrayList
add, add, addAll, addAll, clear, clone, contains, ensureCapacity, equals, forEach, get, hashCode, indexOf, isEmpty, iterator, lastIndexOf, listIterator, listIterator, remove, remove, removeAll, removeIf, removeRange, replaceAll, retainAll, set, size, sort, spliterator, subList, toArray, toArray, trimToSize
-
-
-
-
Constructor Detail
-
ArrayStack
public ArrayStack()
Constructs a new emptyArrayStack
. The initial size is controlled byArrayList
and is currently 10.
-
ArrayStack
public ArrayStack(int initialSize)
Constructs a new emptyArrayStack
with an initial size.- Parameters:
initialSize
- the initial size to use- Throws:
java.lang.IllegalArgumentException
- if the specified initial size is negative
-
-
Method Detail
-
peek
public E peek() throws java.util.EmptyStackException
Returns the top item off of this stack without removing it.- Returns:
- the top item on the stack
- Throws:
java.util.EmptyStackException
- if the stack is empty
-
peek
public E peek(int n) throws java.util.EmptyStackException
Returns the n'th item down (zero-relative) from the top of this stack without removing it.- Parameters:
n
- the number of items down to go- Returns:
- the n'th item on the stack, zero relative
- Throws:
java.util.EmptyStackException
- if there are not enough items on the stack to satisfy this request
-
peek
public E peek(java.lang.Class<?> target) throws java.util.EmptyStackException
- Throws:
java.util.EmptyStackException
-
pop
public E pop() throws java.util.EmptyStackException
Pops the top item off of this stack and return it.- Returns:
- the top item on the stack
- Throws:
java.util.EmptyStackException
- if the stack is empty
-
push
public E push(E item)
Pushes a new item onto the top of this stack. The pushed item is also returned. This is equivalent to callingadd
.- Parameters:
item
- the item to be added- Returns:
- the item just pushed
-
update
public E update(E item) throws java.util.EmptyStackException
Replaces the top item of this stack with another item without removing it.- Returns:
- the top item previously on the stack
- Throws:
java.util.EmptyStackException
- if the stack is empty
-
update
public E update(int n, E item) throws java.util.EmptyStackException
Replaces the n'th item down (zero-relative) from the top of this stack with another item without removing it.- Parameters:
n
- the number of items down to go- Returns:
- the n'th item previously on the stack, zero relative
- Throws:
java.util.EmptyStackException
- if there are not enough items on the stack to satisfy this request
-
search
public int search(E object)
Returns the one-based position of the distance from the top that the specified object exists on this stack, where the top-most element is considered to be at distance1
. If the object is not present on the stack, return-1
instead. Theequals()
method is used to compare to the items in this stack.- Parameters:
object
- the object to be searched for- Returns:
- the 1-based depth into the stack of the object, or -1 if not found
-
-