Class CollectionUtil


  • public class CollectionUtil
    extends Object
    helper/convience methods for working with collections.
    Author:
    Joram Barrez
    • Method Detail

      • singletonMap

        public static Map<String,​Object> singletonMap​(String key,
                                                            Object value)
        Helper method that creates a singleton map. Alternative for Collections.singletonMap(), since that method returns a generic typed map depending on the input type, but we often need a map.
      • asArrayList

        public static <T> List<T> asArrayList​(T[] values)
        Arrays.asList cannot be reliably used for SQL parameters on MyBatis < 3.3.0
      • asHashSet

        public static <T> Set<T> asHashSet​(T... elements)
      • addToMapOfLists

        public static <S,​T> void addToMapOfLists​(Map<S,​List<T>> map,
                                                       S key,
                                                       T value)
      • addToMapOfSets

        public static <S,​T> void addToMapOfSets​(Map<S,​Set<T>> map,
                                                      S key,
                                                      T value)
      • addCollectionToMapOfSets

        public static <S,​T> void addCollectionToMapOfSets​(Map<S,​Set<T>> map,
                                                                S key,
                                                                Collection<T> values)
      • partition

        public static <T> List<List<T>> partition​(List<T> list,
                                                  int partitionSize)
        Chops a list into non-view sublists of length partitionSize. Note: the argument list may be included in the result.
      • collectInList

        public static <T> List<T> collectInList​(Iterator<T> iterator)
      • isEmpty

        public static boolean isEmpty​(Collection<?> collection)