Java Projects with Source Code

Java Projects for Every Skill Level

Java projects on CodeAj range from straightforward CRUD apps to multi-module enterprise systems. Whether you're a student building your first Spring Boot app or a developer who needs a reference implementation for a design pattern, we have something for you.

Spring Boot Web Applications

Our Spring Boot collection includes REST APIs with Spring Security (JWT and OAuth2), web apps with Thymeleaf templates, and microservice architectures with Spring Cloud. Each project uses Spring Data JPA for database access, Spring Validation for input checking, and proper exception handling with @ControllerAdvice. The application.yml files are organized with profiles for dev, test, and production.

Enterprise Patterns

Larger projects demonstrate patterns you'll encounter in professional Java development — repository pattern, service layer, DTO mapping with MapStruct, pagination with Spring Data, audit logging, event-driven communication, and caching with Redis. These patterns are what interviewers ask about and what real codebases use.

Android Applications

Android projects use Kotlin or Java with the latest Android SDK. They include proper MVVM architecture with ViewModel and LiveData, Room database for local storage, Retrofit for API calls, and Navigation Component for screen management. UI follows Material Design 3 guidelines.

Build and Dependency Management

All projects use Maven or Gradle with properly defined dependencies. You won't see version conflicts or missing transitive dependencies. Build files are clean and commented, so you understand what each dependency is for. Multi-module projects use parent POMs or Gradle composite builds.

Setting Up Java Projects

You need JDK 17 or later and your preferred IDE (IntelliJ IDEA Community Edition works great). Import the project as a Maven or Gradle project, let the IDE download dependencies, configure your database connection in application.yml, and run the main class. Spring Boot projects start on port 8080 by default.

Database Setup

Most projects use MySQL or PostgreSQL. SQL dump files and migration scripts (Flyway or Liquibase) are included. Some simpler projects use H2 in-memory database for zero-config setup. The README includes exact database creation commands for your OS.

Java for Academic Submissions

Java is accepted by virtually every university for final year projects. Our Spring Boot projects score well in evaluations because they demonstrate enterprise-level architecture. The included documentation covers system design, class diagrams, and API specifications that professors expect in project reports.