net.gdface.utils

Class CollectionUtils

java.lang.Object

net.gdface.utils.CollectionUtils

public class CollectionUtils
extends java.lang.Object

Author:

guyadong

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	CollectionUtils.DualTransformer<L,R> dual transform type between L and R CollectionUtils.DualTransformer.toRight(Object) L -> R CollectionUtils.DualTransformer.fromRight(Object) R -> L
static interface	CollectionUtils.Function<F,T>

Method Summary

Modifier and Type	Method and Description
static <L,R> CollectionUtils.DualTransformer<L,R>	asDualTransformer(CollectionUtils.Function<L,R> t1, CollectionUtils.Function<R,L> t2)
static <L,R> CollectionUtils.Function<R,L>	asFromRightTransformer(CollectionUtils.DualTransformer<L,R> dual)
static <L,R> CollectionUtils.Function<L,R>	asToRightTransformer(CollectionUtils.DualTransformer<L,R> dual)
static <T> T	checkNotNull(T reference) Ensures that an object reference passed as a parameter to the calling method is not null.
static <T> T	checkNotNull(T reference, java.lang.Object errorMessage) Ensures that an object reference passed as a parameter to the calling method is not null.
static <C extends java.util.Collection<?>> C	checkNotNullElement(C c) Ensures that a collection reference passed as a parameter to the calling method not exists null element if it's not null.
static <K1,K2,V> java.util.Map<K2,V>	tranformKeys(java.util.Map<K1,V> fromMap, CollectionUtils.DualTransformer<K1,K2> transformer) Returns a view of a map where each value is transformed by a function.
static <K1,K2,V> java.util.Map<K2,V>	tranformKeys(java.util.Map<K1,V> fromMap, CollectionUtils.Function<K1,K2> transformer2, CollectionUtils.Function<K2,K1> transformer1)
static <F,T> java.util.Iterator<T>	transform(java.util.Iterator<F> fromIterator, CollectionUtils.Function<? super F,? extends T> transformer) Returns an iterator that applies function to each element of fromIterator. see also Iterators.transform(Iterator, com.google.common.base.Function)
static <E1,E2> java.util.Set<E2>	transform(java.util.Set<E1> fromSet, CollectionUtils.DualTransformer<E1,E2> transformer) Returns a view of a set where each key is transformed by a function.
static <E1,E2> java.util.Set<E2>	transform(java.util.Set<E1> fromSet, CollectionUtils.Function<E1,E2> transformer2, CollectionUtils.Function<E2,E1> transformer1)

Methods inherited from class java.lang.Object

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

Method Detail

asDualTransformer

public static final <L,R> CollectionUtils.DualTransformer<L,R> asDualTransformer(CollectionUtils.Function<L,R> t1,
                                                                                 CollectionUtils.Function<R,L> t2)

asToRightTransformer

public static final <L,R> CollectionUtils.Function<L,R> asToRightTransformer(CollectionUtils.DualTransformer<L,R> dual)

asFromRightTransformer

public static final <L,R> CollectionUtils.Function<R,L> asFromRightTransformer(CollectionUtils.DualTransformer<L,R> dual)

checkNotNull

public static <T> T checkNotNull(T reference)

Ensures that an object reference passed as a parameter to the calling method is not null.

Returns:

the non-null reference that was validated

checkNotNull

public static <T> T checkNotNull(T reference,
                                 java.lang.Object errorMessage)

Ensures that an object reference passed as a parameter to the calling method is not null.

Returns:

the non-null reference that was validated

checkNotNullElement

public static <C extends java.util.Collection<?>> C checkNotNullElement(C c)

Ensures that a collection reference passed as a parameter to the calling method not exists null element if it's not null.

Returns:

the non-null-element reference that was validated

tranformKeys

public static final <K1,K2,V> java.util.Map<K2,V> tranformKeys(java.util.Map<K1,V> fromMap,
                                                               CollectionUtils.Function<K1,K2> transformer2,
                                                               CollectionUtils.Function<K2,K1> transformer1)

See Also:

tranformKeys(Map, DualTransformer)

tranformKeys

public static final <K1,K2,V> java.util.Map<K2,V> tranformKeys(java.util.Map<K1,V> fromMap,
                                                               CollectionUtils.DualTransformer<K1,K2> transformer)

Returns a view of a map where each value is transformed by a function. All other properties of the map, such as iteration order, are left intact.
see also Maps.transformEntries(Map, com.google.common.collect.Maps.EntryTransformer)

Parameters:

fromMap -

transformer -

Returns:

transform

public static final <E1,E2> java.util.Set<E2> transform(java.util.Set<E1> fromSet,
                                                        CollectionUtils.Function<E1,E2> transformer2,
                                                        CollectionUtils.Function<E2,E1> transformer1)

See Also:

transform(Set, DualTransformer)

transform

public static final <E1,E2> java.util.Set<E2> transform(java.util.Set<E1> fromSet,
                                                        CollectionUtils.DualTransformer<E1,E2> transformer)

Returns a view of a set where each key is transformed by a function. All other properties of the map, such as iteration order, are left intact.
see also Maps.transformEntries(Map, com.google.common.collect.Maps.EntryTransformer)

Parameters:

fromSet -

transformer -

Returns:

transform

public static <F,T> java.util.Iterator<T> transform(java.util.Iterator<F> fromIterator,
                                                    CollectionUtils.Function<? super F,? extends T> transformer)

Returns an iterator that applies function to each element of fromIterator.
see also Iterators.transform(Iterator, com.google.common.base.Function)

Parameters:

fromIterator -

transformer -

Returns: