Java Servlet Containers
Java Servlet Containers
Java Servlet Containers are the core runtime environments where Java web applications run. They manage the execution of Java Servlets, which are server-side components used to handle HTTP requests and responses.
What is a Servlet Container?
A Servlet Container (also known as a Web Container) is part of a web server or application server that interacts with Java Servlets. It provides the lifecycle management, multi-threading, security, and communication services required for running web applications based on Java EE (Jakarta EE) standards.
It is responsible for:
- Loading servlet classes.
- Creating and managing servlet instances.
- Handling requests and responses.
- Managing servlet lifecycle methods (
init(),service(),destroy()).
Servlet Container Features
Some of the features are as follows:
- Request handling: Routes incoming HTTP requests to appropriate servlets.
- Lifecycle management: Manages servlet initialization, execution, and destruction.
- Session management: Tracks user sessions using cookies or URL rewriting.
- Security: Provides authentication, authorization, and HTTPS support.
- Concurrency: Handles multiple user requests using multithreading.
- Deployment: Supports deployment of
.war(Web Application Archive) files.
Java Servlet Containers
Apache Tomcat
- Most popular open-source servlet container.
- Supports Servlets, JSP, and WebSocket.
- Lightweight and ideal for standalone web applications.
Jetty
- Lightweight and embeddable.
- Suitable for microservices and asynchronous processing.
- Often used in machine-to-machine communication.
GlassFish
- Full Jakarta EE (formerly Java EE) application server.
- Includes servlet container and other Java EE components (EJB, JPA, etc.).
- Suitable for enterprise applications.
WildFly (formerly JBoss AS)
- Developed by Red Hat.
- Robust, scalable, and full-featured Java EE server.
- Servlet container is part of a larger application server.
WebLogic Server
- Commercial offering by Oracle.
- Enterprise-level performance and scalability.
- Integrates with Oracle products.
WebSphere
- IBM’s enterprise-grade Java application server.
- Includes a servlet container and many enterprise features.
- Often used in large enterprise environments.
Servlet Container vs Application Server
| Servlet Container | Application Server | |
|---|---|---|
| Scope | Manages Servlets and JSP | Manages full Java EE stack |
| Lightweight | Yes | No (typically heavier) |
| Examples | Tomcat, Jetty | GlassFish, WildFly, WebLogic |
| Use case | Simple web apps, REST APIs | Full-scale enterprise applications |
Java Tutorial on this website:
