On Jul 18, 2017 2:25 PM, "Rob Tompkins" <chtom...@gmail.com> wrote:
I'm stuck in the in-between here with the following thought: HashTable certainly feels like a collection of objects, but it clearly extends Dictionary and isn't in the collections family. But we are in java.util here and not in java.lang, so that feels more like it could be in collections. Plus properties are essentially a map, despite they're being implemented on top of hashtable. HashTable<K, V> extends Dictionary<K,V> implements Map<K,V>. Of course, Properties extends HashTable <Object, Object> because legacy. In jdk 9, Properties still extends HashTable. However, HashTable now has a magic package private constructor "HashTable(Void)", which is used by Properties to tell HashTable to go sit in a corner, with all fields left set to default values. Properties now uses a ConcurrentHashMap internally, with only a few methods remaining synchronized. Everything gets delegated to the chm. Still full of unchecked goodness. And a great example of how sometimes inheritance is so useless you just compose and delegate anyway. Simon
