messenger-java-spring-api

Spring Boot backend for a messenger app, providing authentication, chat, presence, and file handling APIs.

Features

• JWT-based auth and Spring Security
• REST APIs for users, friends, chats, and messages
• WebSocket support for realtime updates
• Postgres persistence via Spring Data JPA
• Media/file uploads for avatars and messages

Tech Stack

• Java 17
• Spring Boot 3.5
• PostgreSQL
• Maven
• MapStruct, Lombok

Requirements

• Java 17
• Maven (or use the included Maven Wrapper)
• PostgreSQL

Quick Start

1. Create a Postgres database (default: cryptDB).
2. Update database credentials and JWT secret in application.properties.
3. Run the app.

Run (Maven Wrapper)

./mvnw spring-boot:run

Run (Maven)

mvn spring-boot:run

The server starts on the default Spring Boot port 8080.

Configuration

Main config lives in src/main/resources/application.properties.

Key settings you may want to change:

• spring.datasource.* for Postgres connection
• jwt.secret for JWT signing
• app.avatars.* and app.messages.* for uploads paths and URLs

Uploads are stored under uploads/ by default.

Project Structure

.
├── pom.xml
├── README.md
├── src
│   ├── main
│   │   ├── java
│   │   │   └── com/example/piccrypt
│   │   │       ├── PicCryptBackendApplication.java
│   │   │       ├── config
│   │   │       ├── controllers
│   │   │       ├── dtos
│   │   │       ├── exceptions
│   │   │       ├── mapper
│   │   │       ├── models
│   │   │       ├── repositories
│   │   │       ├── serviceImpl
│   │   │       ├── services
│   │   │       └── types
│   │   └── resources
│   │       └── application.properties
│   └── test
│       └── java/com/example/piccrypt
├── uploads
│   ├── avatars
│   └── messages
└── target
	└── ...

Tests

./mvnw test

Notes

• The default JWT secret in application.properties is for local development only. Replace it for real deployments.
• If you use a different port, set server.port in application.properties.