Package org.apache.camel.util

Class CollectionHelper

java.lang.Object

org.apache.camel.util.CollectionHelper

public final class CollectionHelper
extends Object

A number of helper methods for working with collections

Method Summary

Modifier and Type	Method	Description
static void	appendValue(Map<String,Object> map, String key, Object value)	Sets the value of the entry in the map for the given key, though if the map already contains a value for the given key then the value is appended to a list of values.
static String	collectionAsCommaDelimitedString(Collection<?> col)
static <T> Set<T>	createSetContaining(T... contents)
static Map<String,Object>	flattenKeysInMap(Map<String,Object> map, String separator)	Traverses the given map recursively and flattern the keys by combining them with the optional separator.
static <K,V> Map<K,V>	immutableMapOf(Supplier<Map<K,V>> creator, K key, V value, Object... keyVals)	Build an immutable map from varargs.
static <K,V> Map<K,V>	immutableMapOf(K key, V value, Object... keyVals)	Build an immutable map from varargs.
static <K,V> Map<K,V>	mapOf(Supplier<Map<K,V>> creator, K key, V value, Object... keyVals)	Build a map from varargs.
static <K,V> Map<K,V>	mapOf(K key, V value, Object... keyVals)	Build a map from varargs.
static <K,V> Map<K,V>	mergeMaps(Map<K,V> map, Map<K,V>... maps)	Build a new map that is the result of merging the given list of maps.
static Properties	propertiesOf(String key, String value, String... keyVals)	Build a Properties from varargs.
static Integer	size(Object value)	Returns the size of the collection if it can be determined to be a collection
static <K,V> Map<K,V>	unmodifiableMap(Map<K,V> map)	Build an unmodifiable map on top of a given map.

Methods inherited from class java.lang.Object

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

Method Detail

size

public static Integer size(Object value)

Returns the size of the collection if it can be determined to be a collection

Parameters:

value - the collection

Returns:

the size, or null if not a collection

appendValue

public static void appendValue(Map<String,Object> map,
                               String key,
                               Object value)

Sets the value of the entry in the map for the given key, though if the map already contains a value for the given key then the value is appended to a list of values.

Parameters:

map - the map to add the entry to

key - the key in the map

value - the value to put in the map

createSetContaining

@SafeVarargs
public static <T> Set<T> createSetContaining(T... contents)

collectionAsCommaDelimitedString

public static String collectionAsCommaDelimitedString(Collection<?> col)

flattenKeysInMap

public static Map<String,Object> flattenKeysInMap(Map<String,Object> map,
                                                        String separator)

Traverses the given map recursively and flattern the keys by combining them with the optional separator.

Parameters:

map - the map

separator - optional separator to use in key name, for example a hyphen or dot.

Returns:

the map with flattern keys

unmodifiableMap

public static <K,V> Map<K,V> unmodifiableMap(Map<K,V> map)

Build an unmodifiable map on top of a given map. Note tha thew given map is copied if not null.

Parameters:

map - a map

Returns:

an unmodifiable map.

mapOf

public static <K,V> Map<K,V> mapOf(Supplier<Map<K,V>> creator,
                                               K key,
                                               V value,
                                               Object... keyVals)

Build a map from varargs.

immutableMapOf

public static <K,V> Map<K,V> immutableMapOf(Supplier<Map<K,V>> creator,
                                                        K key,
                                                        V value,
                                                        Object... keyVals)

Build an immutable map from varargs.

mapOf

public static <K,V> Map<K,V> mapOf(K key,
                                               V value,
                                               Object... keyVals)

Build a map from varargs.

immutableMapOf

public static <K,V> Map<K,V> immutableMapOf(K key,
                                                        V value,
                                                        Object... keyVals)

Build an immutable map from varargs.

propertiesOf

public static Properties propertiesOf(String key,
                                      String value,
                                      String... keyVals)

Build a Properties from varargs.

mergeMaps

@SafeVarargs
public static <K,V> Map<K,V> mergeMaps(Map<K,V> map,
                                                   Map<K,V>... maps)

Build a new map that is the result of merging the given list of maps.