Spring Spel

In Spring framework, we mainly use SpEL as annotation in a bean. But SpEL has other use cases as well. 

Like evaluating the expression on the fly. e.g. You can store expression in database & execute on demand.

More documentation can be found on:

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

https://docs.spring.io/spring-framework/reference/core/expressions.html 

https://dzone.com/articles/learn-spring-expression-language-with-examples