com.landawn.abacus.util

Class Maps

java.lang.Object

com.landawn.abacus.util.Maps

public final class Maps
extends java.lang.Object

Note: It's copied from OpenJDK at: http://hg.openjdk.java.net/jdk8u/hs-dev/jdk
Import the useful default Map methods from JDK 1.8 for programming on JDK 7 and Android.

Method Summary

Modifier and Type	Method and Description
static <K,V> V	compute(java.util.Map<K,V> map, K key, BiFunction<? super K,? super V,? extends V> remappingFunction) Attempts to compute a mapping for the specified key and its current mapped value (or null if there is no current mapping).
static <K,V> V	computeIfAbsent(java.util.Map<K,V> map, K key, Function<? super K,? extends V> mappingFunction) If the specified key is not already associated with a value (or is mapped to null), attempts to compute its value using the given mapping function and enters it into this map unless null.
static <K,V> V	computeIfPresent(java.util.Map<K,V> map, K key, BiFunction<? super K,? super V,? extends V> remappingFunction) If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value.
static boolean	contains(java.util.Map<?,?> map, java.util.Map.Entry<?,?> entry) Check if the specified Map contains the specified Entry
static boolean	contains(java.util.Map<?,?> map, java.lang.Object key, java.lang.Object value)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	deepEntity2Map(java.util.Collection<?> entityList)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	deepEntity2Map(java.util.Collection<?> entityList, boolean ignoreNullProperty)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	deepEntity2Map(java.util.Collection<?> entityList, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	deepEntity2Map(java.util.Collection<?> entityList, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames, NamingPolicy keyNamingPolicy)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	deepEntity2Map(java.util.Collection<?> entityList, java.util.Collection<java.lang.String> ignoredPropNames)
static java.util.Map<java.lang.String,java.lang.Object>	deepEntity2Map(java.lang.Object entity)
static java.util.Map<java.lang.String,java.lang.Object>	deepEntity2Map(java.lang.Object entity, boolean ignoreNullProperty)
static java.util.Map<java.lang.String,java.lang.Object>	deepEntity2Map(java.lang.Object entity, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames)
static java.util.Map<java.lang.String,java.lang.Object>	deepEntity2Map(java.lang.Object entity, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames, NamingPolicy keyNamingPolicy)
static java.util.Map<java.lang.String,java.lang.Object>	deepEntity2Map(java.lang.Object entity, java.util.Collection<java.lang.String> ignoredPropNames)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	deepEntity2Map(T resultMap, java.lang.Object entity)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	deepEntity2Map(T resultMap, java.lang.Object entity, boolean ignoreNullProperty)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	deepEntity2Map(T resultMap, java.lang.Object entity, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	deepEntity2Map(T resultMap, java.lang.Object entity, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames, NamingPolicy keyNamingPolicy)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	deepEntity2Map(T resultMap, java.lang.Object entity, java.util.Collection<java.lang.String> ignoredPropNames)
static <K,V> java.util.Map<K,V>	diff(java.util.Map<K,V> map, java.util.Map<? extends K,? extends V> map2)
static <K,V> java.util.Map<K,Pair<V,Nullable<V>>>	difference(java.util.Map<K,V> map, java.util.Map<K,V> map2)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	entity2FlatMap(java.util.Collection<?> entityList)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	entity2FlatMap(java.util.Collection<?> entityList, boolean ignoreNullProperty)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	entity2FlatMap(java.util.Collection<?> entityList, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	entity2FlatMap(java.util.Collection<?> entityList, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames, NamingPolicy keyNamingPolicy)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	entity2FlatMap(java.util.Collection<?> entityList, java.util.Collection<java.lang.String> ignoredPropNames)
static java.util.Map<java.lang.String,java.lang.Object>	entity2FlatMap(java.lang.Object entity)
static java.util.Map<java.lang.String,java.lang.Object>	entity2FlatMap(java.lang.Object entity, boolean ignoreNullProperty)
static java.util.Map<java.lang.String,java.lang.Object>	entity2FlatMap(java.lang.Object entity, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames)
static java.util.Map<java.lang.String,java.lang.Object>	entity2FlatMap(java.lang.Object entity, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames, NamingPolicy keyNamingPolicy)
static java.util.Map<java.lang.String,java.lang.Object>	entity2FlatMap(java.lang.Object entity, java.util.Collection<java.lang.String> ignoredPropNames)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	entity2FlatMap(T resultMap, java.lang.Object entity)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	entity2FlatMap(T resultMap, java.lang.Object entity, boolean ignoreNullProperty)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	entity2FlatMap(T resultMap, java.lang.Object entity, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	entity2FlatMap(T resultMap, java.lang.Object entity, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames, NamingPolicy keyNamingPolicy)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	entity2FlatMap(T resultMap, java.lang.Object entity, java.util.Collection<java.lang.String> ignoredPropNames)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	entity2Map(java.util.Collection<?> entityList)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	entity2Map(java.util.Collection<?> entityList, boolean ignoreNullProperty)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	entity2Map(java.util.Collection<?> entityList, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	entity2Map(java.util.Collection<?> entityList, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames, NamingPolicy keyNamingPolicy)
static java.util.List<java.util.Map<java.lang.String,java.lang.Object>>	entity2Map(java.util.Collection<?> entityList, java.util.Collection<java.lang.String> ignoredPropNames)
static java.util.Map<java.lang.String,java.lang.Object>	entity2Map(java.lang.Object entity)
static java.util.Map<java.lang.String,java.lang.Object>	entity2Map(java.lang.Object entity, boolean ignoreNullProperty)
static java.util.Map<java.lang.String,java.lang.Object>	entity2Map(java.lang.Object entity, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames)
static java.util.Map<java.lang.String,java.lang.Object>	entity2Map(java.lang.Object entity, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames, NamingPolicy keyNamingPolicy)
static java.util.Map<java.lang.String,java.lang.Object>	entity2Map(java.lang.Object entity, java.util.Collection<java.lang.String> ignoredPropNames)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	entity2Map(T resultMap, java.lang.Object entity)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	entity2Map(T resultMap, java.lang.Object entity, boolean ignoreNullProperty)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	entity2Map(T resultMap, java.lang.Object entity, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	entity2Map(T resultMap, java.lang.Object entity, boolean ignoreNullProperty, java.util.Collection<java.lang.String> ignoredPropNames, NamingPolicy keyNamingPolicy)
static <T extends java.util.Map<java.lang.String,java.lang.Object>> T	entity2Map(T resultMap, java.lang.Object entity, java.util.Collection<java.lang.String> ignoredPropNames)
static <K,V> java.util.Map<K,V>	filter(java.util.Map<K,V> map, BiPredicate<? super K,? super V> predicate)
static <K,V> java.util.Map<K,V>	filterByKey(java.util.Map<K,V> map, Predicate<? super K> predicate)
static <K,V> java.util.Map<K,V>	filterByValue(java.util.Map<K,V> map, Predicate<? super V> predicate)
static <K,V> void	forEach(java.util.Map<K,V> map, BiConsumer<? super K,? super V> action) Performs the given action for each entry in this map until all entries have been processed or the action throws an exception.
static <K,V> Nullable<V>	get(java.util.Map<K,V> map, java.lang.Object key)
static <K,V> java.util.List<V>	getIfPresentForEach(java.util.Map<K,V> map, java.util.Collection<?> keys) Returns a list of values of the keys which exist in the specified Map.
static <K,V> V	getOrDefault(java.util.Map<K,V> map, java.lang.Object key, V defaultValue) Returns the value to which the specified key is mapped, or defaultValue if this map contains no mapping for the key.
static <K,V> java.util.List<V>	getOrDefaultForEach(java.util.Map<K,V> map, java.util.Collection<?> keys, V defaultValue)
static <K,V> java.util.Map<K,V>	intersection(java.util.Map<K,V> map, java.util.Map<? extends K,? extends V> map2)
static <K,V> java.util.Map<V,java.util.List<K>>	inverse(java.util.Map<K,? extends java.util.Collection<V>> map)
static <K,V> java.util.Map<V,K>	invert(java.util.Map<K,V> map)
static java.lang.String	join(java.util.Map<?,?> m)
static java.lang.String	join(java.util.Map<?,?> m, char entryDelimiter)
static java.lang.String	join(java.util.Map<?,?> m, char entryDelimiter, char keyValueDelimiter)
static java.lang.String	join(java.util.Map<?,?> m, int fromIndex, int toIndex, char entryDelimiter)
static java.lang.String	join(java.util.Map<?,?> m, int fromIndex, int toIndex, char entryDelimiter, boolean trim)
static java.lang.String	join(java.util.Map<?,?> m, int fromIndex, int toIndex, char entryDelimiter, char keyValueDelimiter)
static java.lang.String	join(java.util.Map<?,?> m, int fromIndex, int toIndex, char entryDelimiter, char keyValueDelimiter, boolean trim)
static java.lang.String	join(java.util.Map<?,?> m, int fromIndex, int toIndex, java.lang.String entryDelimiter)
static java.lang.String	join(java.util.Map<?,?> m, int fromIndex, int toIndex, java.lang.String entryDelimiter, boolean trim)
static java.lang.String	join(java.util.Map<?,?> m, int fromIndex, int toIndex, java.lang.String entryDelimiter, java.lang.String keyValueDelimiter)
static java.lang.String	join(java.util.Map<?,?> m, int fromIndex, int toIndex, java.lang.String entryDelimiter, java.lang.String keyValueDelimiter, boolean trim)
static java.lang.String	join(java.util.Map<?,?> m, java.lang.String entryDelimiter)
static java.lang.String	join(java.util.Map<?,?> m, java.lang.String entryDelimiter, java.lang.String keyValueDelimiter)
static <T> java.util.List<T>	map2Entity(java.lang.Class<T> targetClass, java.util.Collection<java.util.Map<java.lang.String,java.lang.Object>> mList)
static <T> java.util.List<T>	map2Entity(java.lang.Class<T> targetClass, java.util.Collection<java.util.Map<java.lang.String,java.lang.Object>> mList, boolean igoreNullProperty, boolean ignoreUnknownProperty)
static <T> T	map2Entity(java.lang.Class<T> targetClass, java.util.Map<java.lang.String,java.lang.Object> m)
static <T> T	map2Entity(java.lang.Class<T> targetClass, java.util.Map<java.lang.String,java.lang.Object> m, boolean ignoreNullProperty, boolean ignoreUnknownProperty)
static <K,V> V	merge(java.util.Map<K,V> map, K key, V value, BiFunction<? super V,? super V,? extends V> remappingFunction) If the specified key is not already associated with a value or is associated with null, associates it with the given non-null value.
static <K,T> java.util.Map<K,T>	newLinkedHashMap(java.util.Collection<? extends T> c, Function<? super T,? extends K> keyExtractor)
static <K,T> java.util.Map<K,T>	newMap(java.util.Collection<? extends T> c, Function<? super T,? extends K> keyExtractor)
static <K,V> V	putIfAbsent(java.util.Map<K,V> map, K key, V value) If the specified key is not already associated with a value (or is mapped to null) associates it with the given value and returns null, else returns the current value.
static <K,V> boolean	remove(java.util.Map<K,V> map, java.util.Map.Entry<?,?> entry)
static <K,V> boolean	remove(java.util.Map<K,V> map, java.lang.Object key, java.lang.Object value) Removes the entry for the specified key only if it is currently mapped to the specified value.
static boolean	removeAll(java.util.Map<?,?> map, java.util.Collection<?> keys)
static boolean	removeAll(java.util.Map<?,?> map, java.util.Map<?,?> entriesToRemove) The the entries from the specified Map
static <K,V> V	replace(java.util.Map<K,V> map, K key, V value) Replaces the entry for the specified key only if it is currently mapped to some value.
static <K,V> boolean	replace(java.util.Map<K,V> map, K key, V oldValue, V newValue) Replaces the entry for the specified key only if currently mapped to the specified value.
static <K,V> void	replaceAll(java.util.Map<K,V> map, BiFunction<? super K,? super V,? extends V> function) Replaces each entry's value with the result of invoking the given function on that entry until all entries have been processed or the function throws an exception.
static <K,V> java.util.Map<K,Pair<Nullable<V>,Nullable<V>>>	symmetricDifference(java.util.Map<K,V> map, java.util.Map<K,V> map2)

Methods inherited from class java.lang.Object

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

Method Detail

newMap

public static <K,T> java.util.Map<K,T> newMap(java.util.Collection<? extends T> c,
                                              Function<? super T,? extends K> keyExtractor)

newLinkedHashMap

public static <K,T> java.util.Map<K,T> newLinkedHashMap(java.util.Collection<? extends T> c,
                                                        Function<? super T,? extends K> keyExtractor)

get

public static <K,V> Nullable<V> get(java.util.Map<K,V> map,
                                    java.lang.Object key)

getIfPresentForEach

public static <K,V> java.util.List<V> getIfPresentForEach(java.util.Map<K,V> map,
                                                          java.util.Collection<?> keys)

Returns a list of values of the keys which exist in the specified Map. If the key dosn't exist in the Map, No value will be added into the returned list.

Parameters:

map -

keys -

Returns:

getOrDefault

public static <K,V> V getOrDefault(java.util.Map<K,V> map,
                                   java.lang.Object key,
                                   V defaultValue)

Returns the value to which the specified key is mapped, or defaultValue if this map contains no mapping for the key.

Parameters:

key - the key whose associated value is to be returned

defaultValue - the default mapping of the key

Returns:

the value to which the specified key is mapped, or defaultValue if this map contains no mapping for the key

Throws:

java.lang.ClassCastException - if the key is of an inappropriate type for this map (optional)

java.lang.NullPointerException - if the specified key is null and this map does not permit null keys (optional)

Since:

1.8

getOrDefaultForEach

public static <K,V> java.util.List<V> getOrDefaultForEach(java.util.Map<K,V> map,
                                                          java.util.Collection<?> keys,
                                                          V defaultValue)

contains

public static boolean contains(java.util.Map<?,?> map,
                               java.util.Map.Entry<?,?> entry)

Check if the specified Map contains the specified Entry

Parameters:

map -

entry -

Returns:

contains

public static boolean contains(java.util.Map<?,?> map,
                               java.lang.Object key,
                               java.lang.Object value)

intersection

public static <K,V> java.util.Map<K,V> intersection(java.util.Map<K,V> map,
                                                    java.util.Map<? extends K,? extends V> map2)

diff

public static <K,V> java.util.Map<K,V> diff(java.util.Map<K,V> map,
                                            java.util.Map<? extends K,? extends V> map2)

difference

public static <K,V> java.util.Map<K,Pair<V,Nullable<V>>> difference(java.util.Map<K,V> map,
                                                                    java.util.Map<K,V> map2)

symmetricDifference

public static <K,V> java.util.Map<K,Pair<Nullable<V>,Nullable<V>>> symmetricDifference(java.util.Map<K,V> map,
                                                                                       java.util.Map<K,V> map2)

putIfAbsent

public static <K,V> V putIfAbsent(java.util.Map<K,V> map,
                                  K key,
                                  V value)

If the specified key is not already associated with a value (or is mapped to null) associates it with the given value and returns null, else returns the current value.

Parameters:

key - key with which the specified value is to be associated

value - value to be associated with the specified key

Returns:

the previous value associated with the specified key, or null if there was no mapping for the key. (A null return can also indicate that the map previously associated null with the key, if the implementation supports null values.)

Throws:

java.lang.UnsupportedOperationException - if the put operation is not supported by this map (optional)

java.lang.ClassCastException - if the key or value is of an inappropriate type for this map (optional)

java.lang.NullPointerException - if the specified map is null, or if the specified key or value is null, and this map does not permit null keys or values (optional)

java.lang.IllegalArgumentException - if some property of the specified key or value prevents it from being stored in this map (optional)

Since:

1.8

remove

public static <K,V> boolean remove(java.util.Map<K,V> map,
                                   java.util.Map.Entry<?,?> entry)

remove

public static <K,V> boolean remove(java.util.Map<K,V> map,
                                   java.lang.Object key,
                                   java.lang.Object value)

Removes the entry for the specified key only if it is currently mapped to the specified value.

Parameters:

key - key with which the specified value is associated

value - value expected to be associated with the specified key

Returns:

true if the value was removed

Throws:

java.lang.UnsupportedOperationException - if the remove operation is not supported by this map (optional)

java.lang.ClassCastException - if the key or value is of an inappropriate type for this map (optional)

java.lang.NullPointerException - if the specified key or value is null, and this map does not permit null keys or values (optional)

Since:

1.8

removeAll

public static boolean removeAll(java.util.Map<?,?> map,
                                java.util.Collection<?> keys)

Parameters:

map -

keys -

Returns:

true if any key/value was removed, otherwise false.

removeAll

public static boolean removeAll(java.util.Map<?,?> map,
                                java.util.Map<?,?> entriesToRemove)

The the entries from the specified Map

Parameters:

map -

entriesToRemove -

Returns:

true if any key/value was removed, otherwise false.

replace

public static <K,V> boolean replace(java.util.Map<K,V> map,
                                    K key,
                                    V oldValue,
                                    V newValue)

Replaces the entry for the specified key only if currently mapped to the specified value.

Parameters:

key - key with which the specified value is associated

oldValue - value expected to be associated with the specified key

newValue - value to be associated with the specified key

Returns:

true if the value was replaced

Throws:

java.lang.UnsupportedOperationException - if the put operation is not supported by this map (optional)

java.lang.ClassCastException - if the class of a specified key or value prevents it from being stored in this map

java.lang.NullPointerException - if a specified key or newValue is null, and this map does not permit null keys or values

java.lang.NullPointerException - if oldValue is null and this map does not permit null values (optional)

java.lang.IllegalArgumentException - if some property of a specified key or value prevents it from being stored in this map

Since:

1.8

replace

public static <K,V> V replace(java.util.Map<K,V> map,
                              K key,
                              V value)

Replaces the entry for the specified key only if it is currently mapped to some value.

Parameters:

key - key with which the specified value is associated

value - value to be associated with the specified key

Returns:

the previous value associated with the specified key, or null if there was no mapping for the key. (A null return can also indicate that the map previously associated null with the key, if the implementation supports null values.)

Throws:

java.lang.UnsupportedOperationException - if the put operation is not supported by this map (optional)

java.lang.ClassCastException - if the class of the specified key or value prevents it from being stored in this map (optional)

java.lang.NullPointerException - if the specified key or value is null, and this map does not permit null keys or values

java.lang.IllegalArgumentException - if some property of the specified key or value prevents it from being stored in this map

Since:

1.8

replaceAll

public static <K,V> void replaceAll(java.util.Map<K,V> map,
                                    BiFunction<? super K,? super V,? extends V> function)

Replaces each entry's value with the result of invoking the given function on that entry until all entries have been processed or the function throws an exception. Exceptions thrown by the function are relayed to the caller.

Parameters:

function - the function to apply to each entry

Throws:

java.lang.UnsupportedOperationException - if the set operation is not supported by this map's entry set iterator.

java.lang.ClassCastException - if the class of a replacement value prevents it from being stored in this map

java.lang.NullPointerException - if the specified function is null, or the specified replacement value is null, and this map does not permit null values

java.lang.ClassCastException - if a replacement value is of an inappropriate type for this map (optional)

java.lang.NullPointerException - if function or a replacement value is null, and this map does not permit null keys or values (optional)

java.lang.IllegalArgumentException - if some property of a replacement value prevents it from being stored in this map (optional)

java.util.ConcurrentModificationException - if an entry is found to be removed during iteration

Since:

1.8

computeIfAbsent

public static <K,V> V computeIfAbsent(java.util.Map<K,V> map,
                                      K key,
                                      Function<? super K,? extends V> mappingFunction)

If the specified key is not already associated with a value (or is mapped to null), attempts to compute its value using the given mapping function and enters it into this map unless null.

If the function returns null no mapping is recorded. If the function itself throws an (unchecked) exception, the exception is rethrown, and no mapping is recorded. The most common usage is to construct a new object serving as an initial mapped value or memoized result, as in:

 
 map.computeIfAbsent(key, k -> new Value(f(k)));
 

Or to implement a multi-value map, Map<K,Collection<V>>, supporting multiple values per key:

 
 map.computeIfAbsent(key, k -> new HashSet<V>()).add(v);
 

Parameters:

key - key with which the specified value is to be associated

mappingFunction - the function to compute a value

Returns:

the current (existing or computed) value associated with the specified key, or null if the computed value is null

Throws:

java.lang.NullPointerException - if the specified map is null, or the specified key is null and this map does not support null keys, or the mappingFunction is null

java.lang.UnsupportedOperationException - if the put operation is not supported by this map (optional)

java.lang.ClassCastException - if the class of the specified key or value prevents it from being stored in this map (optional)

Since:

1.8

computeIfPresent

public static <K,V> V computeIfPresent(java.util.Map<K,V> map,
                                       K key,
                                       BiFunction<? super K,? super V,? extends V> remappingFunction)

If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value.

If the function returns null, the mapping is removed. If the function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged.

Parameters:

key - key with which the specified value is to be associated

remappingFunction - the function to compute a value

Returns:

the new value associated with the specified key, or null if none

Throws:

java.lang.NullPointerException - if the specified map is null, or the specified key is null and this map does not support null keys, or the remappingFunction is null

java.lang.UnsupportedOperationException - if the put operation is not supported by this map (optional)

java.lang.ClassCastException - if the class of the specified key or value prevents it from being stored in this map (optional)

Since:

1.8

compute

public static <K,V> V compute(java.util.Map<K,V> map,
                              K key,
                              BiFunction<? super K,? super V,? extends V> remappingFunction)

Attempts to compute a mapping for the specified key and its current mapped value (or null if there is no current mapping). For example, to either create or append a String msg to a value mapping:

 
 map.compute(key, (k, v) -> (v == null) ? msg : v.concat(msg))

(Method merge() is often simpler to use for such purposes.)

If the function returns null, the mapping is removed (or remains absent if initially absent). If the function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged.

Parameters:

key - key with which the specified value is to be associated

remappingFunction - the function to compute a value

Returns:

the new value associated with the specified key, or null if none

Throws:

java.lang.NullPointerException - if the specified map is null, or the specified key is null and this map does not support null keys, or the remappingFunction is null

java.lang.UnsupportedOperationException - if the put operation is not supported by this map (optional)

java.lang.ClassCastException - if the class of the specified key or value prevents it from being stored in this map (optional)

Since:

1.8

merge

public static <K,V> V merge(java.util.Map<K,V> map,
                            K key,
                            V value,
                            BiFunction<? super V,? super V,? extends V> remappingFunction)

If the specified key is not already associated with a value or is associated with null, associates it with the given non-null value. Otherwise, replaces the associated value with the results of the given remapping function, or removes if the result is null. This method may be of use when combining multiple mapped values for a key. For example, to either create or append a String msg to a value mapping:

 
 map.merge(key, msg, String::concat)
 

If the function returns null the mapping is removed. If the function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged.

Parameters:

key - key with which the resulting value is to be associated

value - the non-null value to be merged with the existing value associated with the key or, if no existing value or a null value is associated with the key, to be associated with the key

remappingFunction - the function to recompute a value if present

Returns:

the new value associated with the specified key, or null if no value is associated with the key

Throws:

java.lang.UnsupportedOperationException - if the put operation is not supported by this map (optional)

java.lang.ClassCastException - if the class of the specified key or value prevents it from being stored in this map (optional)

java.lang.NullPointerException - if the specified map is null, or the specified key is null and this map does not support null keys or the value or remappingFunction is null

Since:

1.8

forEach

public static <K,V> void forEach(java.util.Map<K,V> map,
                                 BiConsumer<? super K,? super V> action)

Performs the given action for each entry in this map until all entries have been processed or the action throws an exception. Unless otherwise specified by the implementing class, actions are performed in the order of entry set iteration (if an iteration order is specified.) Exceptions thrown by the action are relayed to the caller.

Parameters:

action - The action to be performed for each entry

Throws:

java.lang.NullPointerException - if the specified action is null

java.util.ConcurrentModificationException - if an entry is found to be removed during iteration

Since:

1.8

filterByKey

public static <K,V> java.util.Map<K,V> filterByKey(java.util.Map<K,V> map,
                                                   Predicate<? super K> predicate)

filterByValue

public static <K,V> java.util.Map<K,V> filterByValue(java.util.Map<K,V> map,
                                                     Predicate<? super V> predicate)

filter

public static <K,V> java.util.Map<K,V> filter(java.util.Map<K,V> map,
                                              BiPredicate<? super K,? super V> predicate)

invert

public static <K,V> java.util.Map<V,K> invert(java.util.Map<K,V> map)

inverse

public static <K,V> java.util.Map<V,java.util.List<K>> inverse(java.util.Map<K,? extends java.util.Collection<V>> map)

map2Entity

public static <T> T map2Entity(java.lang.Class<T> targetClass,
                               java.util.Map<java.lang.String,java.lang.Object> m)

map2Entity

public static <T> T map2Entity(java.lang.Class<T> targetClass,
                               java.util.Map<java.lang.String,java.lang.Object> m,
                               boolean ignoreNullProperty,
                               boolean ignoreUnknownProperty)

map2Entity

public static <T> java.util.List<T> map2Entity(java.lang.Class<T> targetClass,
                                               java.util.Collection<java.util.Map<java.lang.String,java.lang.Object>> mList)

map2Entity

public static <T> java.util.List<T> map2Entity(java.lang.Class<T> targetClass,
                                               java.util.Collection<java.util.Map<java.lang.String,java.lang.Object>> mList,
                                               boolean igoreNullProperty,
                                               boolean ignoreUnknownProperty)

entity2Map

public static java.util.Map<java.lang.String,java.lang.Object> entity2Map(java.lang.Object entity)

entity2Map

public static java.util.Map<java.lang.String,java.lang.Object> entity2Map(java.lang.Object entity,
                                                                          boolean ignoreNullProperty)

entity2Map

public static java.util.Map<java.lang.String,java.lang.Object> entity2Map(java.lang.Object entity,
                                                                          java.util.Collection<java.lang.String> ignoredPropNames)

entity2Map

public static java.util.Map<java.lang.String,java.lang.Object> entity2Map(java.lang.Object entity,
                                                                          boolean ignoreNullProperty,
                                                                          java.util.Collection<java.lang.String> ignoredPropNames)

entity2Map

public static java.util.Map<java.lang.String,java.lang.Object> entity2Map(java.lang.Object entity,
                                                                          boolean ignoreNullProperty,
                                                                          java.util.Collection<java.lang.String> ignoredPropNames,
                                                                          NamingPolicy keyNamingPolicy)

entity2Map

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T entity2Map(T resultMap,
                                                                                        java.lang.Object entity)

Parameters:

resultMap -

entity -

Returns:

the input resultMap

entity2Map

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T entity2Map(T resultMap,
                                                                                        java.lang.Object entity,
                                                                                        boolean ignoreNullProperty)

Parameters:

resultMap -

entity -

ignoreNullProperty -

Returns:

the input resultMap

entity2Map

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T entity2Map(T resultMap,
                                                                                        java.lang.Object entity,
                                                                                        java.util.Collection<java.lang.String> ignoredPropNames)

Parameters:

resultMap -

entity -

ignoredPropNames -

Returns:

the input resultMap

entity2Map

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T entity2Map(T resultMap,
                                                                                        java.lang.Object entity,
                                                                                        boolean ignoreNullProperty,
                                                                                        java.util.Collection<java.lang.String> ignoredPropNames)

Parameters:

resultMap -

entity -

ignoreNullProperty -

ignoredPropNames -

Returns:

the input resultMap

entity2Map

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T entity2Map(T resultMap,
                                                                                        java.lang.Object entity,
                                                                                        boolean ignoreNullProperty,
                                                                                        java.util.Collection<java.lang.String> ignoredPropNames,
                                                                                        NamingPolicy keyNamingPolicy)

Parameters:

resultMap -

entity -

ignoreNullProperty -

ignoredPropNames -

keyNamingPolicy -

Returns:

the input resultMap

entity2Map

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> entity2Map(java.util.Collection<?> entityList)

entity2Map

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> entity2Map(java.util.Collection<?> entityList,
                                                                                          boolean ignoreNullProperty)

entity2Map

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> entity2Map(java.util.Collection<?> entityList,
                                                                                          java.util.Collection<java.lang.String> ignoredPropNames)

entity2Map

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> entity2Map(java.util.Collection<?> entityList,
                                                                                          boolean ignoreNullProperty,
                                                                                          java.util.Collection<java.lang.String> ignoredPropNames)

entity2Map

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> entity2Map(java.util.Collection<?> entityList,
                                                                                          boolean ignoreNullProperty,
                                                                                          java.util.Collection<java.lang.String> ignoredPropNames,
                                                                                          NamingPolicy keyNamingPolicy)

deepEntity2Map

public static java.util.Map<java.lang.String,java.lang.Object> deepEntity2Map(java.lang.Object entity)

deepEntity2Map

public static java.util.Map<java.lang.String,java.lang.Object> deepEntity2Map(java.lang.Object entity,
                                                                              boolean ignoreNullProperty)

deepEntity2Map

public static java.util.Map<java.lang.String,java.lang.Object> deepEntity2Map(java.lang.Object entity,
                                                                              java.util.Collection<java.lang.String> ignoredPropNames)

deepEntity2Map

public static java.util.Map<java.lang.String,java.lang.Object> deepEntity2Map(java.lang.Object entity,
                                                                              boolean ignoreNullProperty,
                                                                              java.util.Collection<java.lang.String> ignoredPropNames)

deepEntity2Map

public static java.util.Map<java.lang.String,java.lang.Object> deepEntity2Map(java.lang.Object entity,
                                                                              boolean ignoreNullProperty,
                                                                              java.util.Collection<java.lang.String> ignoredPropNames,
                                                                              NamingPolicy keyNamingPolicy)

deepEntity2Map

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T deepEntity2Map(T resultMap,
                                                                                            java.lang.Object entity)

Parameters:

resultMap -

entity -

Returns:

the input resultMap

deepEntity2Map

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T deepEntity2Map(T resultMap,
                                                                                            java.lang.Object entity,
                                                                                            boolean ignoreNullProperty)

Parameters:

resultMap -

entity -

ignoreNullProperty -

Returns:

the input resultMap

deepEntity2Map

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T deepEntity2Map(T resultMap,
                                                                                            java.lang.Object entity,
                                                                                            java.util.Collection<java.lang.String> ignoredPropNames)

Parameters:

resultMap -

entity -

ignoredPropNames -

Returns:

the input resultMap

deepEntity2Map

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T deepEntity2Map(T resultMap,
                                                                                            java.lang.Object entity,
                                                                                            boolean ignoreNullProperty,
                                                                                            java.util.Collection<java.lang.String> ignoredPropNames)

Parameters:

resultMap -

entity -

ignoreNullProperty -

ignoredPropNames -

Returns:

the input resultMap

deepEntity2Map

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T deepEntity2Map(T resultMap,
                                                                                            java.lang.Object entity,
                                                                                            boolean ignoreNullProperty,
                                                                                            java.util.Collection<java.lang.String> ignoredPropNames,
                                                                                            NamingPolicy keyNamingPolicy)

Parameters:

resultMap -

entity -

ignoreNullProperty -

ignoredPropNames -

keyNamingPolicy -

Returns:

the input resultMap

deepEntity2Map

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> deepEntity2Map(java.util.Collection<?> entityList)

deepEntity2Map

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> deepEntity2Map(java.util.Collection<?> entityList,
                                                                                              boolean ignoreNullProperty)

deepEntity2Map

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> deepEntity2Map(java.util.Collection<?> entityList,
                                                                                              java.util.Collection<java.lang.String> ignoredPropNames)

deepEntity2Map

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> deepEntity2Map(java.util.Collection<?> entityList,
                                                                                              boolean ignoreNullProperty,
                                                                                              java.util.Collection<java.lang.String> ignoredPropNames)

deepEntity2Map

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> deepEntity2Map(java.util.Collection<?> entityList,
                                                                                              boolean ignoreNullProperty,
                                                                                              java.util.Collection<java.lang.String> ignoredPropNames,
                                                                                              NamingPolicy keyNamingPolicy)

entity2FlatMap

public static java.util.Map<java.lang.String,java.lang.Object> entity2FlatMap(java.lang.Object entity)

entity2FlatMap

public static java.util.Map<java.lang.String,java.lang.Object> entity2FlatMap(java.lang.Object entity,
                                                                              boolean ignoreNullProperty)

entity2FlatMap

public static java.util.Map<java.lang.String,java.lang.Object> entity2FlatMap(java.lang.Object entity,
                                                                              java.util.Collection<java.lang.String> ignoredPropNames)

entity2FlatMap

public static java.util.Map<java.lang.String,java.lang.Object> entity2FlatMap(java.lang.Object entity,
                                                                              boolean ignoreNullProperty,
                                                                              java.util.Collection<java.lang.String> ignoredPropNames)

entity2FlatMap

public static java.util.Map<java.lang.String,java.lang.Object> entity2FlatMap(java.lang.Object entity,
                                                                              boolean ignoreNullProperty,
                                                                              java.util.Collection<java.lang.String> ignoredPropNames,
                                                                              NamingPolicy keyNamingPolicy)

entity2FlatMap

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T entity2FlatMap(T resultMap,
                                                                                            java.lang.Object entity)

Parameters:

resultMap -

entity -

Returns:

the input resultMap

entity2FlatMap

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T entity2FlatMap(T resultMap,
                                                                                            java.lang.Object entity,
                                                                                            boolean ignoreNullProperty)

Parameters:

resultMap -

entity -

ignoreNullProperty -

Returns:

the input resultMap

entity2FlatMap

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T entity2FlatMap(T resultMap,
                                                                                            java.lang.Object entity,
                                                                                            java.util.Collection<java.lang.String> ignoredPropNames)

Parameters:

resultMap -

entity -

ignoredPropNames -

Returns:

the input resultMap

entity2FlatMap

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T entity2FlatMap(T resultMap,
                                                                                            java.lang.Object entity,
                                                                                            boolean ignoreNullProperty,
                                                                                            java.util.Collection<java.lang.String> ignoredPropNames)

Parameters:

resultMap -

entity -

ignoreNullProperty -

ignoredPropNames -

Returns:

the input resultMap

entity2FlatMap

public static <T extends java.util.Map<java.lang.String,java.lang.Object>> T entity2FlatMap(T resultMap,
                                                                                            java.lang.Object entity,
                                                                                            boolean ignoreNullProperty,
                                                                                            java.util.Collection<java.lang.String> ignoredPropNames,
                                                                                            NamingPolicy keyNamingPolicy)

Parameters:

resultMap -

entity -

ignoreNullProperty -

ignoredPropNames -

keyNamingPolicy -

Returns:

the input resultMap

entity2FlatMap

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> entity2FlatMap(java.util.Collection<?> entityList)

entity2FlatMap

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> entity2FlatMap(java.util.Collection<?> entityList,
                                                                                              boolean ignoreNullProperty)

entity2FlatMap

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> entity2FlatMap(java.util.Collection<?> entityList,
                                                                                              java.util.Collection<java.lang.String> ignoredPropNames)

entity2FlatMap

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> entity2FlatMap(java.util.Collection<?> entityList,
                                                                                              boolean ignoreNullProperty,
                                                                                              java.util.Collection<java.lang.String> ignoredPropNames)

entity2FlatMap

public static java.util.List<java.util.Map<java.lang.String,java.lang.Object>> entity2FlatMap(java.util.Collection<?> entityList,
                                                                                              boolean ignoreNullProperty,
                                                                                              java.util.Collection<java.lang.String> ignoredPropNames,
                                                                                              NamingPolicy keyNamingPolicy)

join

public static java.lang.String join(java.util.Map<?,?> m)

join

public static java.lang.String join(java.util.Map<?,?> m,
                                    char entryDelimiter)

join

public static java.lang.String join(java.util.Map<?,?> m,
                                    java.lang.String entryDelimiter)

join

public static java.lang.String join(java.util.Map<?,?> m,
                                    int fromIndex,
                                    int toIndex,
                                    char entryDelimiter)

join

public static java.lang.String join(java.util.Map<?,?> m,
                                    int fromIndex,
                                    int toIndex,
                                    char entryDelimiter,
                                    boolean trim)

join

public static java.lang.String join(java.util.Map<?,?> m,
                                    int fromIndex,
                                    int toIndex,
                                    java.lang.String entryDelimiter)

join

public static java.lang.String join(java.util.Map<?,?> m,
                                    int fromIndex,
                                    int toIndex,
                                    java.lang.String entryDelimiter,
                                    boolean trim)

join

public static java.lang.String join(java.util.Map<?,?> m,
                                    char entryDelimiter,
                                    char keyValueDelimiter)

join

public static java.lang.String join(java.util.Map<?,?> m,
                                    java.lang.String entryDelimiter,
                                    java.lang.String keyValueDelimiter)

join

public static java.lang.String join(java.util.Map<?,?> m,
                                    int fromIndex,
                                    int toIndex,
                                    char entryDelimiter,
                                    char keyValueDelimiter)

join

public static java.lang.String join(java.util.Map<?,?> m,
                                    int fromIndex,
                                    int toIndex,
                                    char entryDelimiter,
                                    char keyValueDelimiter,
                                    boolean trim)

join

public static java.lang.String join(java.util.Map<?,?> m,
                                    int fromIndex,
                                    int toIndex,
                                    java.lang.String entryDelimiter,
                                    java.lang.String keyValueDelimiter)

join

public static java.lang.String join(java.util.Map<?,?> m,
                                    int fromIndex,
                                    int toIndex,
                                    java.lang.String entryDelimiter,
                                    java.lang.String keyValueDelimiter,
                                    boolean trim)