HashMap source code and thread unsafe analysis

This article analyzes HashMap from 4 aspects:
1. Initialize HashMap
2. HashMap's put method source code
3. HashMap's get method source code
4. Why HashMap is thread-unsafe For the

specific content, please refer to my article in the WeChat public account: https ://mp.weixin.qq.com/s/ZPl2ND9j2phSBBpod4fGSg