About the Java collection knowledge necessary for the Java interview, some big guys finally summarized it!

I think Java collection is the most important knowledge point in Java foundation, and Java collection must be mastered. In the internship/autumn recruitment interview, as long as you face Java, you must have Java collections.

Java Collection Mind Map



Java collection source notes

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One, study guide

1. Java Collection Study Guide

• 1.1 Before learning a technology, you must know why you want to learn it!

• 1.2 How to start learning Java collections

• 1.3 Assemble advancement and interview



二、Collection

1. Introduction to Collection

• 1.1 Why do you need Collection

• 1.2 The difference between array and collection

• 1.3 The origin and function of Collection

2. Introduction to Iterator

3. Introduction to List Collection

• 3.1 List collection commonly used subclasses

4. Introduction to Set collection

• 4.1 Common Subclasses of Set Collection



Three, List collection

1. ArrayList analysis

• 1.1 Construction method

• 1.2Add method

• 1.3 get method

• 1.4 set method

• 1.5remove method

• 1.6 More details

2. The difference between Vector and ArrayList

3. LinkedList analysis

• 3.1 Construction method

• 3.2add method

• 3.3remove method

• 3.4 get method

• 3.5set method

4. List collection summary



Four, Map collection

1. Introduction to Map

• 1.1 Why do we need Map

• 1.2 The difference between Map and Collection

• 1.3Map function

2. Introduction to hash tables

• 2.1 Working principle of hash table

3. Introduction to Red-Black Tree

• 3.1 Review the binary search tree

• 3.2 Knowing the new 2-3 tree

• 3.3 From 2-3 trees to red-black trees

• 3.4 Basic knowledge of red-black tree



Five, HashMap

1. HashMap analysis

• 1.1 HashMap construction method

• 1.2put method

• 1.3 get method

• 1.4remove method

2. Comparison of HashMap and Hashtable

3. HashMap summary

The notes are handwritten throughout. I hope you don’t throw them into your favorites when you get them! Forward + follow, add VX (tkzl6666) to get the full version of "Java Collection Source Study Notes"

六、LinkedHashMap

1 、 LinkedHashMap

• 1.1LinkedHashMap domain

• 1.2 LinkedHashMap rewriting method

• 1.3 Construction method

• 1.4put method

• 1.5 get method

• 1.6remove method

• 1.7 Ways to traverse

2, LinkedHashMap summary



Seven, TreeMap

1. Anatomy of TreeMap

• 1.1TreeMap domain

• 1.2TreeMap construction method

• 1.3put method

• 1.4 get method

• 1.5remove method

• 1.6 Traversal method

2. TreeMap summary



Eight, ConcurrentHashMap

1. Anatomy of ConCurrentHashMap

• 1.1 First knowledge of ConCurrentHashMap

• 1.2 JDK1.7 low-level implementation

• 1.3 Why do I need ConCurrentHashMap with Hashtable

• 1.4 A brief introduction to CAS algorithm and volatile

• 1.5ConCurrentHashMap domain

• 1.6ConCurrentHashMap construction method

• 1.7put method

• 1.8get method

2. ConcurrentHashMap summary



Nine, Set

• 1. Anatomy of HashSet

• 2. Anatomy of TreeSet

• 3. Anatomy of LinkedHashSet

• 4. Set collection summary



十、CopyOnWriteArrayList

1、Vector和SynchronizedList

• 1.1 Review the thread-safe Vector and SynchronizedList

• 1.2 Vector and SynchronizedList may have problems

2. Introduction to CopyOnWriteArrayList(Set)

• 2.1 CopyOnWriteArrayList implementation principle



Eleven, Java collection interview questions

• 1. The difference between ArrayList and Vector

• 2. The difference between HashMap and Hashtable

• 3. The difference between List and Map

• 4. The elements in the Set cannot be repeated, so what method is used to distinguish whether they are repeated or not? Is it to use == or equals()?

• 5. The difference between Collection and Collections

• 6. Tell me the storage performance and characteristics of ArrayList and LinkedList

• 7. The difference between Enumeration and Iterator interfaces

• 8. What are the characteristics of ListIterator

• 9. What is the concurrent collection class?

• 10. If the key value of HashMap in Java is a class object, what conditions need to be met by the class?

• 11. What are the best practices related to the Java collection framework

• 12. How to improve efficiency by adding 10,000 pieces of data to the ArrayList collection