Why is it not recommended to use scriptlets and scripting elements in JSP?

Servlets, expressions, and declarations in JSP mix presentation logic and business logic, which makes maintenance and testing difficult. The MVC architecture is violated, pages become less readable and manageable.

It is recommended to use:

• Expression Language (EL): For accessing data from context.
• JSTL (JSP Standard Tag Library): For loops, conditional operators, and data formatting.
• Custom Tags: For encapsulating complex presentation logic.

Example of EL and JSTL:

<!-- Accessing an attribute from request scope -->
<p>User name: ${requestScope.userName}</p>

<!-- Loop over a list -->
<c:forEach items="${users}" var="user">
  <p>${user.firstName} ${user.lastName}</p>
</c:forEach>

<!-- Conditional operator -->
<c:if test="${user.isActive}">
  <p>Active user</p>
</c:if>

Advantages of abandoning scriptlets:

• Separation of concerns: Clear separation of presentation and business logic.
• Improved readability: JSP pages become declarative, not procedural.
• Ease of maintenance and testing: Presentation logic is separated from other code.
• Reusability: Custom tags can be reused across pages.
• Security: Less chance of malicious code injection through scriptlets.