What classes are subclasses of the Collection interface in Java?

In Java, the Collection interface is the base for most collections and has several main subclasses (implementations) that extend its functionality. The main subclasses of the Collection interface include:

• List — an ordered collection that allows duplicates. Examples of implementations:

  • ArrayList
  • LinkedList
  • Vector

• Set — a collection that does not allow duplicates. Examples of implementations:

  • HashSet
  • LinkedHashSet
  • TreeSet

• Queue — a collection for storing elements in processing order (usually FIFO). Examples of implementations:

  • LinkedList (implements both List and Queue)
  • PriorityQueue

Thus, all these classes are subclasses (implementations) of the Collection interface and provide different ways to store and manage groups of objects.