Collections were redesigned to improve below:
- performance of HashMap with key collisions. The new HashMaps were handling collisions with a balanced tree instead of a LinkedList. These changes were only applied to HashMap , LinkedHashMap and ConcurrentHashMap.
- Aggregate Functions are defined in collection frameworks to collaborate with lambda expressions (This will be explained in Lambda expressions)
- Now Collections have forEach methods as default implementation to facilitate streams.
- Java 8 allows interfaces to have default implementations .