1. The difference between List and Set
2. How does HashSet ensure non-repetitiveness
3. Is HashMap thread-safe, and why is it not thread-safe (it is best to draw a picture to illustrate that it is not safe in a multi-threaded environment)?
4. HashMap expansion process
5 , The difference between HashMap 1.7 and 1.8, explain what optimizations have been made in 1.8 and how to optimize them?
6, final finally finalize
7, strong reference, soft reference, weak reference, virtual reference
8, Java reflection
9, Arrays.sort implementation principle and Collection implementation principle
10, LinkedHashMap application
11, cloneable interface implementation principle
12, exception classification and processing Mechanism
13, the difference between wait and sleep
14, how arrays are allocated in memory
2. How does HashSet ensure non-repetitiveness
3. Is HashMap thread-safe, and why is it not thread-safe (it is best to draw a picture to illustrate that it is not safe in a multi-threaded environment)?
4. HashMap expansion process
5 , The difference between HashMap 1.7 and 1.8, explain what optimizations have been made in 1.8 and how to optimize them?
6, final finally finalize
7, strong reference, soft reference, weak reference, virtual reference
8, Java reflection
9, Arrays.sort implementation principle and Collection implementation principle
10, LinkedHashMap application
11, cloneable interface implementation principle
12, exception classification and processing Mechanism
13, the difference between wait and sleep
14, how arrays are allocated in memory