What Is New in Apache Tomcat 5.5
Tomcat 5.5 is a significant update focused on aligning with the latest Java standards and refining its core servlet container functionality. This release primarily streamlines the upgrade path from older versions while introducing key support for newer Java platforms.
| Category | Key Changes |
|---|---|
| Java Version Support | Requires JRE 1.4 or later; official support for Java 5 |
| Performance | Faster JSP compilation and reduced memory usage |
| Compatibility | Updated to support newer versions of Eclipse JDT for JSP compilation |
| Configuration | Deprecated the old jasper JSP compiler |
| Bug Fixes | Numerous fixes for memory leaks, class loading, and request handling |
Why did the Java requirement change for Tomcat 5.5?
Tomcat 5.5 dropped support for Java 1.3 to take advantage of performance and stability improvements in newer Java runtimes. This shift allows the container to utilize features in JRE 1.4 and Java 5, which results in a more efficient server.
In practice, this meant you had to upgrade your JDK to at least version 1.4 to run Tomcat 5.5. This was a necessary move for the project to keep pace with the evolving Java ecosystem and to phase out older, less secure JVMs.
How was JSP compilation improved?
The biggest change was replacing the old jasper compiler with the Eclipse JDT compiler. This switch significantly sped up the compilation of Java Server Pages, which directly reduces the time it takes to reload applications during development.
This matters because slow JSP compilation was a common pain point for developers. The new compiler is not only faster but also more reliable, leading to fewer intermittent compilation failures and a smoother development experience overall.
What are the key memory management fixes?
This release addressed several critical memory leaks related to class loading and application reloading. One notable fix prevents memory from being consumed when web applications are stopped and redeployed repeatedly.
For anyone running long-lived production instances, these fixes were crucial. They prevent the container from gradually running out of memory, which was a common cause of instability and required periodic restarts in previous versions.
FAQ
Can I run Tomcat 5.5 with Java 1.3?
No. Tomcat 5.5 requires at least a JRE 1.4. This change was made to utilize newer Java features and improve overall performance and stability.
What happened to the old jasper JSP compiler?
It was deprecated in favor of the Eclipse JDT compiler. The new compiler is significantly faster and is the recommended option for JSP compilation in this version.
Is it safe to upgrade from Tomcat 5.0?
Yes, the upgrade path is well-tested. The main consideration is ensuring your JDK is version 1.4 or later and verifying that your applications are compatible with the newer JSP compiler.
Were there any security fixes in this release?
While not the primary focus of this version's release notes, various underlying improvements contribute to a more stable and secure container. Always refer to the specific security advisories for detailed information.
Does Tomcat 5.5 support Java 5 features in JSPs?
Yes, with its requirement for JRE 1.4 or later, Tomcat 5.5 fully supports the syntax and features introduced in Java 5 within your JSP pages.