json in spring boot

1. https://stackoverflow.com/questions/44839753/returning-json-object-as-response-in-spring-boot?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa
2. https://stackoverflow.com/questions/40874012/object-to-json-serialization-inside-thymeleaf-template?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa
3.