笔记
https://howtodoinjava.com/spring-boot2/h2-database-example/
https://www.cnblogs.com/v1haoge/p/9959855.html
http://www.h2database.com/html/features.html#in_memory_databases
https://www.baeldung.com/spring-boot-h2-database
https://www.cnblogs.com/cnjavahome/p/8995650.html
https://www.cnblogs.com/xdp-gacl/p/4171024.html
https://www.cnblogs.com/langtianya/p/3807639.html
junit5
https://javabydeveloper.com/junit-5-tutorial/
https://javabydeveloper.com/spring-boot-junit-5-test-example/
GC viewer
https://liuhao163.github.io/%E6%9F%A5%E7%9C%8BGC%E7%9A%84%E5%88%A9%E5%99%A8%E4%B9%8B%E4%B8%80GCVIEWER/
https://segmentfault.com/a/1190000039097867
https://github.com/chewiebug/GCViewer
GC
https://blog.devgenius.io/java-garbage-collection-what-is-the-young-generation-old-generation-and-permanent-generation-953462ae2598
https://www.oracle.com/webfolder/technetwork/tutorials/obe/java/gc01/index.html#t5
https://www.jianshu.com/p/72f08b621e32