Java.util.HashMap -- why HashMap extends AbstractMap and implement Map?
134042
Why do many Collection classes in Java extend the abstract class and implement the interface as well?
93555
HashMap with multiple values under the same key
132020
Why nested abstract class in java
27908
Can we instantiate an abstract class?
143178
Java abstract interface
63308
Why does ArrayList have "implements List"?
89342
How to putAll on Java hashMap contents of one to another, but not replace existing keys and values?
36203
Why isn't ArrayList marked [Obsolete]?
132711
Generics and inheritance: need a complex Map instance
21883
Difference between HashSet and HashMap?
62369
Iterate through a HashMap
40523
Component.find() Called From Child Extending an Abstract Component Fails
92741
Iterating over the map and calling another method
76854
When does HashSet 'add' method calls equals?
57929
How to read and write a HashMap to a file?
139818
Why implement interface explicitly?
6330
What's the difference between ConcurrentHashMap and Collections.synchronizedMap(Map)?