enumset

How to store EnumSet in the DB (using Hibernate)? @Entity public class A { public static enum SOME_ENUM { A, B, C }; private EnumSet<SOME_ENUM> myEnumSet = EnumSet.of(SOME_ENUM.A, SOME_ENUM.B); ... ... } If I try to persist the above, I get exception of course. I wanted to use @CollectionOfElements, but it is deprecated. Is there any alternative of @CollectionOfElements? Is there a way to store EnumSet in a single column without writing UserType? Thanks! hibernate does not have built in support for such things. Note that when dealing with hibernate and collections you should really only be

The following is from the Implementation Note section of Java doc of EnumMap : Implementation note: All basic operations execute in constant time. They are likely (though not guaranteed) to be faster than their HashMap counterparts. I have seen a similar line in the java doc for EnumSet also . I want to know why is it more likely that EnumSets and EnumMaps will be more faster than their hashed counterparts ? EnumSet is backed by a bit array. Since the number of different items you can put in EnumSet is known in advance, we can simply reserve one bit for each enum value. You can imagine similar

While going through the EnumSet<E> of method, I have seen multiple overloaded implementations of of method: public static <E extends Enum<E>> EnumSet<E> of(E e) public static <E extends Enum<E>> EnumSet<E> of(E e1, E e2) . . public static <E extends Enum<E>> EnumSet<E> of(E e1, E e2, E e3, E e4, E e5) and then another overloaded method with varargs public static <E extends Enum<E>> EnumSet<E> of(E first, E... rest) { EnumSet<E> result = noneOf(first.getDeclaringClass()); result.add(first); for (E e : rest) result.add(e); return result; } When this varargs could have handled the other

EnumSet , as old as the enum itself (both since Java 5), is supposed to be a noncompromizing replacement for the use case of bitfields: as fast and lean as the bitfield (well, except for not being a primitive type), and typesafe to boot. On the other hand, the most recent and for years the most anticipated Java API—the Streams API—unashamedly employs bitfields for Spliterator 's characteristics . Should I consider the above as a clear admission by the core Java experts that EnumSet is not that good after all? Should I reconsider the common best-practice advice to never use bitfields? Rohit

I have the following example: import java.util.EnumSet; import java.util.Iterator; public class SizeSet { public static void main(String[] args) { EnumSet largeSize = EnumSet.of(Size.XL,Size.XXL,Size.XXXL); for(Iterator it = largeSize.iterator();it.hasNext();){ Size size = (Size)it.next(); System.out.println(size); } } } enum Size { S, M, L, XL, XXL, XXXL; } In this code I can understand that the Enum creates an Enum type of Sizes. My question is: is largeSize an object of EnumSet type? What does it really mean? I really want to understand it better. JB Nizet As for any variable, its type is

I maintain a large document archive and I often use bit fields to record the status of my documents during processing or when validating them. My legacy code simply uses static int constants such as: static int DOCUMENT_STATUS_NO_STATE = 0 static int DOCUMENT_STATUS_OK = 1 static int DOCUMENT_STATUS_NO_TIF_FILE = 2 static int DOCUMENT_STATUS_NO_PDF_FILE = 4 This makes it pretty easy to indicate the state a document is in, by setting the appropriate flags. For example: status = DOCUMENT_STATUS_NO_TIF_FILE | DOCUMENT_STATUS_NO_PDF_FILE; Since the approach of using static constants is bad