org.jdbi.v3.guava

Class GuavaCollectors

java.lang.Object

org.jdbi.v3.guava.GuavaCollectors

public class GuavaCollectors
extends Object

Provides Collectors for Guava collection types.

Supported container types:

• com.google.common.base.Optional<T> (throws an exception if more than one row in result)
• com.google.common.collect.ImmutableList<T>
• com.google.common.collect.ImmutableSet<T>
• com.google.common.collect.ImmutableSortedSet<T extends Comparable>

Supported Maps and Multimaps types - for rows mapped to Map.Entry<K, V>:

• com.google.common.collect.BiMap<K, V>
• com.google.common.collect.ImmutableMap<K, V>
• com.google.common.collect.Multimap<K, V>
• com.google.common.collect.ListMultimap<K, V>
• com.google.common.collect.ArrayListMultimap<K, V>
• com.google.common.collect.LinkedListMultimap<K, V>
• com.google.common.collect.SetMultimap<K, V>
• com.google.common.collect.HashMultimap<K, V>
• com.google.common.collect.TreeMultimap<K, V>
• com.google.common.collect.ImmutableMultimap<K, V>
• com.google.common.collect.ImmutableListMultimap<K, V>
• com.google.common.collect.ImmutableSetMultimap<K, V>

Method Summary

Modifier and Type	Method and Description
static CollectorFactory	factory()
static <K,V> Collector<Map.Entry<K,V>,?,com.google.common.collect.ArrayListMultimap<K,V>>	toArrayListMultimap() Returns a Collector that accumulates Map.Entry<K, V> input elements into an ArrayListMultimap<K, V>.
static <K,V> Collector<Map.Entry<K,V>,?,com.google.common.collect.BiMap<K,V>>	toHashBiMap() Returns a Collector that accumulates Map.Entry<K, V> input elements into a HashBiMap<K, V>.
static <K,V> Collector<Map.Entry<K,V>,?,com.google.common.collect.HashMultimap<K,V>>	toHashMultimap() Returns a Collector that accumulates Map.Entry<K, V> input elements into a HashMultimap<K, V>.
static <K,V> Collector<Map.Entry<K,V>,?,com.google.common.collect.ImmutableListMultimap<K,V>>	toImmutableListMultimap() Returns a Collector that accumulates Map.Entry<K, V> input elements into an ImmutableListMultimap<K, V>.
static <K,V> Collector<Map.Entry<K,V>,?,com.google.common.collect.ImmutableMap<K,V>>	toImmutableMap() Returns a Collector that accumulates Map.Entry<K, V> input elements into an ImmutableMap<K, V>.
static <K,V> Collector<Map.Entry<K,V>,?,com.google.common.collect.ImmutableSetMultimap<K,V>>	toImmutableSetMultimap() Returns a Collector that accumulates Map.Entry<K, V> input elements into an ImmutableSetMultimap<K, V>.
static <K,V> Collector<Map.Entry<K,V>,?,com.google.common.collect.LinkedListMultimap<K,V>>	toLinkedListMultimap() Returns a Collector that accumulates Map.Entry<K, V> input elements into a LinkedListMultimap<K, V>.
static <K,V,M extends com.google.common.collect.Multimap<K,V>> Collector<Map.Entry<K,V>,?,M>	toMultimap(Supplier<M> multimapFactory) Returns a Collector that accumulates Map.Entry<K, V> input elements into a Multimap<K, V> of the supplied type.
static <T> Collector<T,?,com.google.common.base.Optional<T>>	toOptional() Returns a Collector that accumulates 0 or 1 input elements into Guava's Optional<T>.
static <K extends Comparable,V extends Comparable> Collector<Map.Entry<K,V>,?,com.google.common.collect.TreeMultimap<K,V>>	toTreeMultimap() Returns a Collector that accumulates Map.Entry<K, V> input elements into a TreeMultimap<K, V>.

Methods inherited from class java.lang.Object

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

Method Detail

factory

public static CollectorFactory factory()

Returns:

a CollectorFactory which knows how to create all supported Guava types

toOptional

public static <T> Collector<T,?,com.google.common.base.Optional<T>> toOptional()

Returns a Collector that accumulates 0 or 1 input elements into Guava's Optional<T>. The returned collector will throw IllegalStateException whenever 2 or more elements are present in a stream. Null elements are mapped to Optional.absent().

Type Parameters:

T - the collected type

Returns:

a Collector which collects 0 or 1 input elements into a Guava Optional<T>.

toImmutableMap

public static <K,V> Collector<Map.Entry<K,V>,?,com.google.common.collect.ImmutableMap<K,V>> toImmutableMap()

Returns a Collector that accumulates Map.Entry<K, V> input elements into an ImmutableMap<K, V>.

Type Parameters:

K - the type of map keys

V - the type of map values

Returns:

a Collector which collects map entry elements into an ImmutableMap, in encounter order.

toHashBiMap

public static <K,V> Collector<Map.Entry<K,V>,?,com.google.common.collect.BiMap<K,V>> toHashBiMap()

Returns a Collector that accumulates Map.Entry<K, V> input elements into a HashBiMap<K, V>. The returned collector will throw IllegalStateException whenever a set of input elements contains multiple entries with the same key.

Type Parameters:

K - the type of map keys

V - the type of map values

Returns:

a Collector which collects map entry elements into a HashBiMap, in encounter order.

toImmutableListMultimap

public static <K,V> Collector<Map.Entry<K,V>,?,com.google.common.collect.ImmutableListMultimap<K,V>> toImmutableListMultimap()

Returns a Collector that accumulates Map.Entry<K, V> input elements into an ImmutableListMultimap<K, V>.

Type Parameters:

K - the type of map keys

V - the type of map values

Returns:

a Collector which collects map entry elements into an ImmutableListMultimap, in encounter order.

toImmutableSetMultimap

public static <K,V> Collector<Map.Entry<K,V>,?,com.google.common.collect.ImmutableSetMultimap<K,V>> toImmutableSetMultimap()

Returns a Collector that accumulates Map.Entry<K, V> input elements into an ImmutableSetMultimap<K, V>.

Type Parameters:

K - the type of map keys

V - the type of map values

Returns:

a Collector which collects map entry elements into an ImmutableSetMultimap, in encounter order.

toArrayListMultimap

public static <K,V> Collector<Map.Entry<K,V>,?,com.google.common.collect.ArrayListMultimap<K,V>> toArrayListMultimap()

Returns a Collector that accumulates Map.Entry<K, V> input elements into an ArrayListMultimap<K, V>.

Type Parameters:

K - the type of map keys

V - the type of map values

Returns:

a Collector which collects map entry elements into an ArrayListMultimap, in encounter order.

toLinkedListMultimap

public static <K,V> Collector<Map.Entry<K,V>,?,com.google.common.collect.LinkedListMultimap<K,V>> toLinkedListMultimap()

Returns a Collector that accumulates Map.Entry<K, V> input elements into a LinkedListMultimap<K, V>.

Type Parameters:

K - the type of map keys

V - the type of map values

Returns:

a Collector which collects map entry elements into a LinkedListMultimap, in encounter order.

toHashMultimap

public static <K,V> Collector<Map.Entry<K,V>,?,com.google.common.collect.HashMultimap<K,V>> toHashMultimap()

Returns a Collector that accumulates Map.Entry<K, V> input elements into a HashMultimap<K, V>.

Type Parameters:

K - the type of map keys

V - the type of map values

Returns:

a Collector which collects map entry elements into a ArrayListMultimap, in encounter order.

toTreeMultimap

public static <K extends Comparable,V extends Comparable> Collector<Map.Entry<K,V>,?,com.google.common.collect.TreeMultimap<K,V>> toTreeMultimap()

Returns a Collector that accumulates Map.Entry<K, V> input elements into a TreeMultimap<K, V>.

Type Parameters:

K - the type of map keys

V - the type of map values

Returns:

a Collector which collects map entry elements into a TreeMultimap, in encounter order.

toMultimap

public static <K,V,M extends com.google.common.collect.Multimap<K,V>> Collector<Map.Entry<K,V>,?,M> toMultimap(Supplier<M> multimapFactory)

Returns a Collector that accumulates Map.Entry<K, V> input elements into a Multimap<K, V> of the supplied type.

Type Parameters:

K - the type of map keys

V - the type of map values

M - a supplier of your multimap type

Parameters:

multimapFactory - a Supplier which return a new, empty Multimap of the appropriate type.

Returns:

a Collector which collects map entry elements into a Multiamp, in encounter order.