public class CollectionUtil
extends java.lang.Object
Modifier and Type | Class and Description |
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static class |
CollectionUtil.DefaultingMap<K,V>
A defaulting map, which returns a default value when a value that does not exist in the map is looked up.
|
static class |
CollectionUtil.MultiMap<K,V>
Simple multi-map for convenience of storing collections in map values.
|
static class |
CollectionUtil.Partitioner<V,K>
Deprecated.
use Collectors.groupingBy instead
|
Modifier and Type | Field and Description |
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static java.util.Comparator<java.lang.Object> |
OBJECT_TOSTRING_COMPARATOR
Simple case-insensitive lexical comparator of objects using their
Object.toString() value. |
Constructor and Description |
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CollectionUtil() |
Modifier and Type | Method and Description |
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static <T> T |
getSoleElement(java.util.Collection<T> items) |
static java.lang.String |
join(java.util.Collection<?> items,
java.lang.String inBetween)
Construct a string by toString()ing each item in the collection with inBetween between each item.
|
static <T> java.util.Collection<T> |
makeCollection(java.util.Iterator<T> i) |
static <T> java.util.List<T> |
makeList(T... list) |
static <T> java.util.Set<T> |
makeSet(T... list) |
static <K,V> java.util.Map<K,java.util.Collection<V>> |
partition(java.util.Collection<V> collection,
CollectionUtil.Partitioner<V,K> p)
Deprecated.
use java8 .stream().collect(Collectors.groupingBy(()-> function)) instead
|
static <K,V> java.util.Map<K,java.util.Collection<V>> |
partition(java.util.Collection<V> collection,
java.util.function.Function<? super V,? extends K> keyer)
Partitions a collection into groups based on a characteristics of that group.
|
public static final java.util.Comparator<java.lang.Object> OBJECT_TOSTRING_COMPARATOR
Object.toString()
value.public static <T> java.util.List<T> makeList(T... list)
public static <T> java.util.Set<T> makeSet(T... list)
public static <T> java.util.Collection<T> makeCollection(java.util.Iterator<T> i)
public static java.lang.String join(java.util.Collection<?> items, java.lang.String inBetween)
public static <T> T getSoleElement(java.util.Collection<T> items)
@Deprecated public static <K,V> java.util.Map<K,java.util.Collection<V>> partition(java.util.Collection<V> collection, CollectionUtil.Partitioner<V,K> p)
public static <K,V> java.util.Map<K,java.util.Collection<V>> partition(java.util.Collection<V> collection, java.util.function.Function<? super V,? extends K> keyer)