The best way to assign an immutable instance to a Collection in Java
- by Ali
Today I was reading through some Hibernate code and I encounter something interesting.
There is a class called CollectionHelper that defines the following constant varibale:
public final class CollectionHelper {
public static final List EMPTY_LIST = Collections.unmodifiableList( new ArrayList(0 ) ;
public static final Collection EMPTY_COLLECTION = Collections.unmodifiableCollection(new ArrayList(0) );
public static final Map EMPTY_MAP = Collections.unmodifiableMap( new HashMap(0) );
They have used these constants to initialize collections with immutable instances. Why they didn't simply use the Collections.EMPTY_LIST for initializing lists? Is there a benefit in using the following method?