Difference between include directive, include action and JSTL import tag in JSP? Answer

There are three main ways to include the content of one JSP into another:

include directive

JSP include action

and JSTL import tag

The include directive provides static inclusion. It adds the content of the resource specified by its file attribute, which could be HTML, JSP, or any other resource at translation time.

Any change you make in the file to be included after JSP is translated will not be picked up by the include directive.

Difference between include() and forward() methods of RequestDispatcher in Servlert

What is the difference between include and forward methods of RequestDispatcher interface is one of the frequently asked Servlet questions from Java EE interviews and we'll see how you can answer this question on your interview. You get the RequestDispatcher reference either from ServletContext or ServletRequest interface and even though both include() and forward() method allow a Servlet to interact with another servlet, the main difference between include() and forward is that the include() method is used to load the contents of the specified resource (could be a Servlet, JSP, or static resource like HTML files) directly into the Servlet's response, as if it is part of the calling Servlet. 

Difference between jsp:include and jsp:forward action- Example

JSP provides standard actions to do things without using Java inside the scriptlet. Two of such standard actions, which help JSP to interact with other server resources e.g. another JSP, Servlet, or HTML files are, include and forward actions. The <jsp:forward> action enables you to forward an HTTP request to a static HTML file, a servlet, or another JSP. It has an attribute called page, which accepts the URL of another resource as shown below:
<jsp:forward page="URL" />