Top Apache Tomcat Alternatives

Apache Tomcat is a server-based interactive Java servlet execution environment. It enables developers to build web applications purely based on Java Server Pages and Java Expression Language. The system powers many of the enterprise-grade applications hosted on the internet. It also allows WebSockets to be implemented. Tomcat has several Connectors that serve as integrations to third-party applications and services. Started as a Java Servlet container, it has now expanded to support a variety of Java implementations, and enterprises choose Tomcat for hosting its web apps.

Tomcat server explained

Apache Tomcat server is a special kind of Java server supported by the Java ecosystem. It supports mainly the Java servlet applications and acts as a JSP container tool. JSP requires server-side configuration for it to execute and produce outputs. JSP routing is handled by Apache Tomcat, while the source code is written by the developer and hosted on the Tomcat server.

Tomcat can be expanded using a variety of different components, including Coyote, Catalina, and Jasper. These components have different functionalities but work together to implement the working of the server. Tomcat is a well-documented technology with a good core engine extensibility ratio. Several various Java API and JSP specifications still use Apache Tomcat as a reliable environment.

Components of Tomcat

Tomcat consists of several different components that perform various tasks, and these together are the reason why it is the most trusted web server framework in the world, even after decades of its release. The main components are Catalina, Coyote, and Jasper. The Catalina is a component that enables its servlet container feature and is the backbone of Apache Tomcat. Cataline implements the execution methods of Java Server Pages and Servlets. The database is divided into Realms consisting of users, passwords, and access roles. It can help to enforce Container-Managed Security, as mentioned in the Servlet specifications.

Coyote refers to the Tomcat Server component. It is a connector that talks to the webserver part over HTTP protocol and listens to incoming data requests over the specific TCP port on the webserver. The application is processed and forwarded to the Tomcat engine, which analyses the request and sends back data. Coyote helped Tomcat to support a variety of API, including the Java Persistence API.

Functions of the JSP Engine

It has a built-in JSP Engine component named Jasper. It compiles JSP files into pure Java servlet codes that could be handled by the Catalina component. It also converts these back to JSP files and recompiles them at runtime. Jasper makes the older code available for server execution even when the newer version is being compiled. This enables a downtime-free implementation of the webserver. Once the servlet is compiled completely, it replaces the older version.

It also has three more components added in Tomcat 7 version, which is called Cluster, High Availability, and Web application. These aim to manage large applications and provide efficient load balancing. The availability feature builds on Jasper's less downtime approach and makes it better by scheduling system updates on the production server. It routes traffic to a temporary location and port number without affecting the primary environment.