Last checked and updated on April 20, 2026What Is New in JSP 4.0
Jakarta Server Pages 4.0 is a maintenance release that primarily focuses on aligning with its new platform home under the Jakarta EE namespace. The core functionality remains stable, with key updates being the required support for newer expression language features and namespace changes.
| Category | Description |
|---|---|
| Namespace Update | All APIs and tag libraries have moved from javax.servlet.jsp to the jakarta.servlet.jsp namespace. |
| Expression Language | Now requires Expression Language 4.0, which introduces new operators and functionality that JSP can leverage. |
| Specification Clarifications | Includes various clarifications and minor updates to the specification document for better precision. |
Why did the package names change from javax to jakarta?
The package name change is the most significant update for developers. This change was necessary due to the transition of Java EE from Oracle to the Eclipse Foundation, which required a rebranding to Jakarta EE.
In practice, this means you'll need to update all your import statements and taglib URI declarations in your JSP files. For example, the old javax.servlet.jsp.JspWriter is now jakarta.servlet.jsp.JspWriter.
This is a breaking change for existing applications, but it's a crucial step for the future of the platform under an open-source governance model.
What new Expression Language features can I use in my JSPs?
JSP 4.0 mandates support for Expression Language (EL) 4.0. This brings powerful new operators directly into your JSP pages, making scriptlets even less necessary.
You now have access to the Elvis operator for safe navigation and default values, and the assignment operator within expressions. This allows for more concise and expressive logic directly in your template.
For instance, you can write ${user.profile?.name ?: 'Guest'} to safely navigate and provide a default, which simplifies a lot of common null-checking patterns.
Are there any new tags or directives in this release?
No, JSP 4.0 does not introduce new tags or directives. The core JSP syntax remains unchanged and stable.
The release is about modernization and alignment, not expanding the core feature set. The stability is actually a benefit for maintenance, as you don't have to learn new syntax while updating your namespace imports.
This approach reinforces that JSP's role is as a mature, reliable view technology within the broader Jakarta EE ecosystem.
FAQ
Is JSP 4.0 backwards compatible with my existing applications?
No, it is not directly backwards compatible due to the mandatory package name change from javax.* to jakarta.*. Your application will require code changes to compile and run on a JSP 4.0 implementation.
Do I have to use EL 4.0 in my JSPs now?
While the specification requires that the container supports EL 4.0, your existing JSP pages using older EL syntax will continue to work. You can choose to adopt the new EL 4.0 operators at your own pace.
What is the main reason for this release if there are no new features?
The primary goal was to complete the namespace migration to Jakarta EE. This ensures JSP's continued development as part of the Jakarta EE platform and provides a consistent foundation for all related technologies.
Which Jakarta Servlet version is required for JSP 4.0?
Jakarta Server Pages 4.0 requires Jakarta Servlet 6.0. The specifications are tightly coupled, and you will need a server that supports both the Servlet 6.0 and JSP 4.0 APIs.
Where can I find the official specification document?
The complete Jakarta Server Pages 4.0 Specification is available for reference on the Jakarta EE website (PDF).