HTTP - 304

https://blog.csdn.net/testcs_dn/article/details/84833920/?utm_medium=distribute.pc_relevant.none-task-blog-2_defaultbaidujs_baidulandingword~default-1--blog-107571015.235^v43pc_blog_bottom_relevance_base4&spm=1001.2101.3001.4242.2&utm_relevant_index=4

https://blog.csdn.net/hutongxue434/article/details/107571015