Expression Language (EL) - Is it specific to JSP or general purpose?

Question

I am trying to understand Expression Language (EL) . I referred the wiki for this.

I still have some doubts on this:

1. What exactly is Expression Language?

2. Is Expression Language closely related to JSP Or used as an independent technology?

3. Is it applicable in web-technologies only or a general purposes technology?

Answer 1

What exactly is Expression Language?

It is a language of expressions for interrogating the state of JavaBeans.

Is Expression Language closely related to JSP Or used as an independent technology?

EL is used in JSPs and JSF, and a similar expression language is used in Spring. (There are probably other examples too.) Certainly Spring EL is used in contexts that have nothing to do with the web.

Is it applicable in web-technologies only or a general purposes technology?

In theory, EL could be used as part of any framework that uses components that follow the JavaBeans "protocol". All someone needs to do is adapt the specification and implement it.