🚀 J2EE-Interceptors

📝 Project Overview

J2EE-Interceptors is a simple yet detailed Java EE project that demonstrates the power of interceptors in enterprise applications. The project showcases how to use custom annotations and interceptors to manage cross-cutting concerns such as logging, authentication, and timer event handling in EJB components. By leveraging interceptor bindings, this project provides a modular and reusable approach to adding behavior before, after, or around business method invocations.

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📽️ Demo Video

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🗂️ Project Structure

J2EE-Interceptors/
├── src/
│   └── main/
│       ├── java/
│       │   └── lk.jlat.web.interceptor/
│       │       ├── annotation/
│       │       │   ├── Login.java
│       │       │   └── TimeOutLogger.java
│       │       ├── ejb/
│       │       │   ├── TimerSessionBean.java
│       │       │   └── UserSessionBean.java
│       │       ├── interceptor/
│       │       │   ├── AInterceptor.java
│       │       │   ├── LoginInterceptor.java
│       │       │   ├── TestInterceptor.java
│       │       │   └── TimerInterceptor.java
│       │       └── servlet/
│       │           └── Test.java
│       └── resources/
├── pom.xml

📦 Module Details

🟦 annotation

• Login.java
  Custom annotation for marking methods or classes that require login-related interception.

• TimeOutLogger.java
  Custom annotation for binding timeout logging interceptors to EJB timer methods.

🟦 ejb

• TimerSessionBean.java
  Stateless EJB demonstrating scheduled tasks with timer events, using the @TimeOutLogger annotation for interception.

• UserSessionBean.java
  Stateless EJB for user actions, annotated with @Login to trigger authentication and logging interceptors.

🟦 interceptor

• AInterceptor.java
  Interceptor bound to @Login, logs and processes method invocations with a specified priority.

• LoginInterceptor.java
  Another @Login-bound interceptor, demonstrating ordered execution and authentication checks.

• TestInterceptor.java
  Demonstrates lifecycle interception (@AroundConstruct, @PostConstruct, @PreDestroy) and method-level interception.

• TimerInterceptor.java
  Intercepts timer events (@AroundTimeout) for beans annotated with @TimeOutLogger.

🟦 servlet

• Test.java
  Servlet that triggers EJB methods to demonstrate interceptor execution in action.

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⚙️ Key Features

• ✅ Demonstrates creation and use of custom interceptor binding annotations.
• ✅ Shows how to apply multiple interceptors to EJB components and control execution order with priorities.
• ✅ Covers both business method and timer event interception.
• ✅ Includes lifecycle event interception for advanced use cases.
• ✅ Modular and extensible structure for easy learning and experimentation.

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💡 How It Works

• Custom Annotations:
  @Login and @TimeOutLogger are used to declaratively bind interceptors to EJB methods or classes.

• Multiple Interceptors:
  Interceptors like AInterceptor and LoginInterceptor are executed in order of their @Priority values, enabling layered cross-cutting logic.

• Timer Interception:
  TimerSessionBean uses @Schedule for periodic tasks, with TimerInterceptor capturing and logging timer events.

• Lifecycle Interception:
  TestInterceptor demonstrates how to intercept bean construction, initialization, and destruction phases.

• Servlet Trigger:
  The Test servlet invokes EJB methods, providing an entry point to observe interceptor behavior in a real web environment.

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🛠️ Technologies Used

• Java 11
• Jakarta EE 10 (EJB, Interceptors, Servlet)
• Maven

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📚 Learning Outcomes

• ✅ Understand the concept and implementation of interceptors in Java EE.
• ✅ Learn to design custom interceptor binding annotations.
• ✅ Explore advanced use cases like timer and lifecycle event interception.
• ✅ Gain practical experience with modular enterprise Java application structure.

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🧑‍💻 Author

Chamika Gayashan
Undergraduate Software Engineer | Sri Lanka
Linkedin: @chamikathereal
Current date: Sunday, June 22, 2025, 12:30 AM +0530