public
class
CollectionUtil
extends Object| java.lang.Object | |
| ↳ | com.pnfsoftware.jeb.util.collect.CollectionUtil |
Class Overview
Convenience methods for Java Collection collections, in particular, List lists.
Summary
| Public Constructors | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| CollectionUtil() | |||||||||||
| Public Methods | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| static <T> Collection<T> | addNonNulls(Collection<T> dst, T... elts) | ||||||||||
| static <T> Collection<T> | addNonNulls(Collection<T> dst, Collection<? extends T> src) | ||||||||||
| static <T, K extends Comparable<K>> T |
binarySearch(List<T> list, K key, IExtractor<T, K> extractor)
Perform a binary search in an ordered list.
| ||||||||||
| static <T, K extends Comparable<K>> int |
binarySearchEx(List<? extends T> list, K key, IExtractor<T, ? extends K> extractor, Comparator<K> cc)
Perform a binary search in an ordered list.
| ||||||||||
| static <T> boolean | compare(Collection<? extends T> c1, Collection<? extends T> c2, boolean sorted) | ||||||||||
| static <T> boolean | compareByReference(Collection<? extends T> c1, Collection<? extends T> c2, boolean sorted) | ||||||||||
| static boolean |
contains(Collection<?> c, Object v)
Safely check if an object is present within a collection.
| ||||||||||
| static boolean |
containsNonNull(Iterable<?> c)
Determine if the given iterable contains one or more non-null elements.
| ||||||||||
| static boolean |
containsNull(Iterable<?> c)
Determine if the given iterable contains one or more null elements.
| ||||||||||
| static <T> boolean |
containsReference(Collection<? extends T> c, T o)
Determine if the collection contains the object reference (differs from
contains(Object) by checking reference equality == instead
of equals(Object) equality) | ||||||||||
| static <T> int |
count(Collection<T> coll, T item)
Count elements using
equals(Object). | ||||||||||
| static <T> Iterable<T> |
doubleCollectionIterable(Collection<T> coll1, Collection<T> coll2)
Create a generator that will iterate over two collections, starting with the first one, then
the second one.
| ||||||||||
| static <T> boolean | hasIntersection(Collection<? extends T> c1, Collection<? extends T> c2) | ||||||||||
| static <T> int |
identityCount(Collection<T> coll, T item)
Count elements using
==. | ||||||||||
| static <T> Set<T> |
intersect(Collection<? extends T> c1, Collection<? extends T> c2)
Return the intersection of 2 collections (order of collection parameters does not matter).
| ||||||||||
| static <T> List<T> |
intersection(List<? extends T> c1, List<? extends T> c2)
This method is deprecated.
Use
intersect(Collection, Collection) | ||||||||||
|
[Expand]
Inherited Methods | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
From class
java.lang.Object
| |||||||||||
Public Constructors
public CollectionUtil ()
Public Methods
public static Collection<T> addNonNulls (Collection<T> dst, T... elts)
public static Collection<T> addNonNulls (Collection<T> dst, Collection<? extends T> src)
public static T binarySearch (List<T> list, K key, IExtractor<T, K> extractor)
Perform a binary search in an ordered list.
Parameters
| list | a list of ordered items |
|---|---|
| key | the ordering key for the items. |
| extractor | key extractor |
Returns
- the element, null if not found
public static int binarySearchEx (List<? extends T> list, K key, IExtractor<T, ? extends K> extractor, Comparator<K> cc)
Perform a binary search in an ordered list.
Parameters
| list | a list of ordered items |
|---|---|
| key | the ordering key for the items. |
| extractor | key extractor |
Returns
- the zero+ index of the found element; else, the negative insertion index of the ghost element
public static boolean compare (Collection<? extends T> c1, Collection<? extends T> c2, boolean sorted)
public static boolean compareByReference (Collection<? extends T> c1, Collection<? extends T> c2, boolean sorted)
public static boolean contains (Collection<?> c, Object v)
Safely check if an object is present within a collection.
Parameters
| c | collection, potentially null |
|---|---|
| v | object, potentially null |
Returns
- true IFF the object is contained in the collection
public static boolean containsNonNull (Iterable<?> c)
Determine if the given iterable contains one or more non-null elements.
public static boolean containsNull (Iterable<?> c)
Determine if the given iterable contains one or more null elements.
public static boolean containsReference (Collection<? extends T> c, T o)
Determine if the collection contains the object reference (differs from
contains(Object) by checking reference equality == instead
of equals(Object) equality)
Parameters
| c | collection to loop into |
|---|---|
| o | element whose presence in this collection is to be tested |
Returns
- true if the collection contains the specified element
public static Iterable<T> doubleCollectionIterable (Collection<T> coll1, Collection<T> coll2)
Create a generator that will iterate over two collections, starting with the first one, then the second one.
This method is convenient to iterate over two collections without having to create an intermediate list holding the elements.
Parameters
| coll1 | first collection |
|---|---|
| coll2 | second collection |
Returns
- an iterable
public static boolean hasIntersection (Collection<? extends T> c1, Collection<? extends T> c2)
public static int identityCount (Collection<T> coll, T item)
Count elements using ==.
public static Set<T> intersect (Collection<? extends T> c1, Collection<? extends T> c2)
Return the intersection of 2 collections (order of collection parameters does not matter).
Parameters
| c1 | first collection |
|---|---|
| c2 | second collection |
Returns
- a set of intersection
public static List<T> intersection (List<? extends T> c1, List<? extends T> c2)
This method is deprecated.
Use intersect(Collection, Collection)
Return the intersection of 2 lists. May contain duplicated elements.