"Spring" is one of the two major Java frameworks today. I will explain what are the major features of this framework, DI (Dependency Injection) and Thymeleaf.
DI is to externally set the information required for the formation requirements of an object. For example, if you have the following situation:
Class A → Class B Class A has a dependency on class B (class B has a dependency on class A)
When DI is applied, the class B information required for class A is cut out to the outside, so the situation of class B can be ignored and class A can be executed.
In other words, there is no such thing as "I can't test class A because there is still an error in class B". This is the advantage of DI.
Thymeleaf is a template engine that is used as standard in Spring Boot. Since Thymeleaf describes the variable part with the attribute value, it does not collapse even if it is displayed on the browser.
So, "If you modify the design, it will not work. However, if you modify the function so that it works normally, the design will collapse." This is the advantage of Thymeleaf.