Class CollectionUtil

  • public class CollectionUtil
    extends Object
    • Constructor Detail

      • CollectionUtil

        public CollectionUtil()
    • Method Detail

      • powerSet

        public static <T> Set<Set<T>> powerSet​(Collection<T> originalSet)
      • createIfNull

        public static <T> List<T> createIfNull​(List<T> currentValue)
        Returns passed currentValue if it is not null and creates a new ArrayList if it is null.

        Example: values = createIfNull(values)
      • createIfNull

        public static <T> T[] createIfNull​(T[] arguments)
        Returns a new empty array if the passed array is null.
      • createIfNull

        public static <T> Set<T> createIfNull​(Set<T> currentValue)
        Returns a new empty set if the passed set is null.
      • createIfNull

        public static <T,​E> Map<T,​E> createIfNull​(Map<T,​E> currentValue)
        Returns a new empty map if the passed map is null.
      • flatten

        public static Map<String,​Object> flatten​(Map<String,​Object> map)
        Converts a set of nested maps (like from yaml/json) into a flat map with dot-separated properties
      • findKeyInMapIgnoreCase

        public static String findKeyInMapIgnoreCase​(String key,
                                                    Map<String,​Object> map)
        Find the actual key in a map, by searching the keys in the map and checking them ignoring case.
        key - the key to search for, in any case
        map - the map in which to search
        the properly cased key, if found, or null if not found