K0 - An upper bound on the key type of the generated multimap.V0 - An upper bound on the value type of the generated multimap.@Beta @GwtCompatible @CheckReturnValue public abstract class MultimapBuilder<K0,V0> extends Object
A builder for a multimap implementation that allows customization of the backing map and value collection implementations used in a particular multimap.
This can be used to easily configure multimap data structure implementations not provided explicitly in com.diffplug.common.collect, for example:
ListMultimap<String, Integer> treeListMultimap =
MultimapBuilder.treeKeys().arrayListValues().build();
SetMultimap<Integer, MyEnum> hashEnumMultimap =
MultimapBuilder.hashKeys().enumSetValues(MyEnum.class).build();
MultimapBuilder instances are immutable. Invoking a configuration method has no effect on the receiving instance; you must store and use the new builder instance it returns instead.
The generated multimaps are serializable if the key and value types are serializable, unless stated otherwise in one of the configuration methods.
| Modifier and Type | Class and Description |
|---|---|
static class |
MultimapBuilder.ListMultimapBuilder<K0,V0>
A specialization of
MultimapBuilder that generates ListMultimap instances. |
static class |
MultimapBuilder.MultimapBuilderWithKeys<K0>
An intermediate stage in a
MultimapBuilder in which the key-value collection map implementation has been specified, but the value collection implementation has not. |
static class |
MultimapBuilder.SetMultimapBuilder<K0,V0>
A specialization of
MultimapBuilder that generates SetMultimap instances. |
static class |
MultimapBuilder.SortedSetMultimapBuilder<K0,V0>
A specialization of
MultimapBuilder that generates SortedSetMultimap instances. |
| Modifier and Type | Method and Description |
|---|---|
abstract <K extends K0,V extends V0> |
build()
Returns a new, empty
Multimap with the specified implementation. |
<K extends K0,V extends V0> |
build(Multimap<? extends K,? extends V> multimap)
Returns a
Multimap with the specified implementation, initialized with the entries of multimap. |
static <K0 extends Enum<K0>> |
enumKeys(Class<K0> keyClass)
Uses an
EnumMap to map keys to value collections. |
static MultimapBuilder.MultimapBuilderWithKeys<Object> |
hashKeys()
Uses a
HashMap to map keys to value collections. |
static MultimapBuilder.MultimapBuilderWithKeys<Object> |
hashKeys(int expectedKeys)
Uses a
HashMap to map keys to value collections, initialized to expect the specified number of keys. |
static MultimapBuilder.MultimapBuilderWithKeys<Object> |
linkedHashKeys()
Uses a
LinkedHashMap to map keys to value collections. |
static MultimapBuilder.MultimapBuilderWithKeys<Object> |
linkedHashKeys(int expectedKeys)
Uses a
LinkedHashMap to map keys to value collections, initialized to expect the specified number of keys. |
static MultimapBuilder.MultimapBuilderWithKeys<Comparable> |
treeKeys()
Uses a naturally-ordered
TreeMap to map keys to value collections. |
static <K0> MultimapBuilder.MultimapBuilderWithKeys<K0> |
treeKeys(Comparator<K0> comparator)
Uses a
TreeMap sorted by the specified comparator to map keys to value collections. |
public static MultimapBuilder.MultimapBuilderWithKeys<Object> hashKeys()
Uses a HashMap to map keys to value collections.
public static MultimapBuilder.MultimapBuilderWithKeys<Object> hashKeys(int expectedKeys)
Uses a HashMap to map keys to value collections, initialized to expect the specified number of keys.
IllegalArgumentException - if expectedKeys < 0public static MultimapBuilder.MultimapBuilderWithKeys<Object> linkedHashKeys()
Uses a LinkedHashMap to map keys to value collections.
The collections returned by Multimap.keySet(), Multimap.keys(), and Multimap.asMap() will iterate through the keys in the order that they were first added to the multimap, save that if all values associated with a key are removed and then the key is added back into the multimap, that key will come last in the key iteration order.
public static MultimapBuilder.MultimapBuilderWithKeys<Object> linkedHashKeys(int expectedKeys)
Uses a LinkedHashMap to map keys to value collections, initialized to expect the specified number of keys.
The collections returned by Multimap.keySet(), Multimap.keys(), and Multimap.asMap() will iterate through the keys in the order that they were first added to the multimap, save that if all values associated with a key are removed and then the key is added back into the multimap, that key will come last in the key iteration order.
public static MultimapBuilder.MultimapBuilderWithKeys<Comparable> treeKeys()
Uses a naturally-ordered TreeMap to map keys to value collections.
The collections returned by Multimap.keySet(), Multimap.keys(), and Multimap.asMap() will iterate through the keys in sorted order.
For all multimaps generated by the resulting builder, the Multimap.keySet() can be safely cast to a SortedSet, and the Multimap.asMap() can safely be cast to a SortedMap.
public static <K0> MultimapBuilder.MultimapBuilderWithKeys<K0> treeKeys(Comparator<K0> comparator)
Uses a TreeMap sorted by the specified comparator to map keys to value collections.
The collections returned by Multimap.keySet(), Multimap.keys(), and Multimap.asMap() will iterate through the keys in sorted order.
For all multimaps generated by the resulting builder, the Multimap.keySet() can be safely cast to a SortedSet, and the Multimap.asMap() can safely be cast to a SortedMap.
Multimaps generated by the resulting builder will not be serializable if comparator is not serializable.
public static <K0 extends Enum<K0>> MultimapBuilder.MultimapBuilderWithKeys<K0> enumKeys(Class<K0> keyClass)
Uses an EnumMap to map keys to value collections.
public abstract <K extends K0,V extends V0> Multimap<K,V> build()
Returns a new, empty Multimap with the specified implementation.