use freeform to generate some diagrams when reading spring framework code.

this is useful for security-related configuration like password.

https://docs.spring.io/spring-integration/reference/html/dsl.html#java-dsl

https://docs.spring.io/spring-framework/docs/3.0.x/spring-framework-reference/html/jms.html

https://spring.io/guides/gs/batch-processing/

https://www.baeldung.com/jackson