Package org.springframework.webflow.core.collection

Class CollectionUtils

java.lang.Object

org.springframework.webflow.core.collection.CollectionUtils

public class CollectionUtils
extends Object

A utility class for working with attribute and parameter collections used by Spring Web FLow.

Author:

Keith Donald, Erwin Vervaet

Field Summary

Fields

Modifier and Type	Field	Description
static final AttributeMap<Object>	EMPTY_ATTRIBUTE_MAP	The shared, singleton empty attribute map instance.
static final Iterator	EMPTY_ITERATOR	The shared, singleton empty iterator instance.

Method Summary

Modifier and Type	Method	Description
static <T> boolean	addAllNoDuplicates(List<T> target, T... objects)	Add all given objects to given target list.
static <E> Iterator<E>	emptyIterator()
static <V> AttributeMap<V>	singleEntryMap(String attributeName, V attributeValue)	Factory method that returns a unmodifiable attribute map with a single entry.
static <E> Iterator<E>	toIterator(Enumeration<E> enumeration)	Factory method that adapts an enumeration to an iterator.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

EMPTY_ITERATOR

public static final Iterator EMPTY_ITERATOR

The shared, singleton empty iterator instance.

EMPTY_ATTRIBUTE_MAP

public static final AttributeMap<Object> EMPTY_ATTRIBUTE_MAP

The shared, singleton empty attribute map instance.

Method Details

emptyIterator

public static <E> Iterator<E> emptyIterator()

toIterator

public static <E> Iterator<E> toIterator(Enumeration<E> enumeration)

Factory method that adapts an enumeration to an iterator.

Parameters:

enumeration - the enumeration

Returns:

the iterator

singleEntryMap

public static <V> AttributeMap<V> singleEntryMap(String attributeName,
 V attributeValue)

Factory method that returns a unmodifiable attribute map with a single entry.

Parameters:

attributeName - the attribute name

attributeValue - the attribute value

Returns:

the unmodifiable map with a single element

addAllNoDuplicates

public static <T> boolean addAllNoDuplicates(List<T> target,
 T... objects)

Add all given objects to given target list. No duplicates will be added. The contains() method of the given target list will be used to determine whether or not an object is already in the list.

Parameters:

target - the collection to which to objects will be added

objects - the objects to add

Returns:

whether or not the target collection changed