LetsTalk

LetsTalk is a Java Swing desktop chat and photo-sharing application backed by a MySQL relational database. The repository includes the application source code, database scripts, ERD/report artifacts.

Tech Stack

Layer	Technology
UI	Java Swing
Application	Java 8, Maven
Persistence	JDBC
Database	MySQL
Media handling	Java ImageIO, BLOB storage

Repository Structure

.
+-- src/main/java
|   +-- Constants
|   +-- Helper
|   +-- JDBC
|   +-- Panels
|   +-- TableStruture
|   +-- Thread
|   +-- Main.java
+-- src/main/resources/Image
+-- document
|   +-- LetsTalk Data Script.sql
|   +-- LetsTalk Query List.pdf
|   +-- LetsTalk Tables Script.pdf
|   +-- LetsTalkERD.pdf
|   +-- report.pdf
|   +-- screenshots
+-- pom.xml
+-- LetsTalk_Executable.jar

Core Features

• User registration and login
• Profile editing with avatar upload
• Friend management and group creation
• One-to-one chat history retrieval
• Text and image message sending
• Emoji ownership and selection
• Photo post upload and browsing
• Analytical SQL queries used for project reporting, such as average user age by gender and users with complete friendship coverage

Application Walkthrough

Registration	Chat Workspace
New users enter profile details, choose a headshot image, select gender, and submit to create a database-backed account.	The main chat view combines navigation, friend selection, conversation history, message input, and attachment actions.

Profile And Friendship	Friend Discovery
Users can view profile information, interests, birthday, age, and friendship actions from the profile panel.	The add-friend panel demonstrates database-backed user lookup and reporting-style queries from the course requirements.

ERD

For the full usage report, see document/report.pdf.

Architecture

The project is organized around three main layers:

• Panels: Swing UI screens and interaction flows.
• JDBC: database connection and query operations.
• TableStruture: Java model classes that map to database tables.

Typical chat flow:

1. MainPanel manages the current application state.
2. ChatSelectPanel chooses a friend conversation.
3. ChatPanel renders messages and sends new messages.
4. Insert writes message, text/image subtype, and communication event rows.
5. Read loads conversation history and enriches it with sender and timestamp data.
6. MessageReceiver refreshes the active conversation periodically.

Local Setup

Prerequisites:

• JDK 8 or newer
• Maven
• MySQL 8.x

Create a MySQL database named letstalk, recreate the schema from document/LetsTalk Tables Script.pdf, then load the seed data from document/LetsTalk Data Script.sql if you want the demo records.

Configure the database connection with environment variables:

$env:LETSTALK_DB_URL="jdbc:mysql://localhost:3306/letstalk"
$env:LETSTALK_DB_USER="letstalk"
$env:LETSTALK_DB_PASSWORD="your-password"

Build and run:

mvn clean package
java -jar target/LetsTalk-jar-with-dependencies.jar

Future Improvements

• Add password hashing instead of storing raw passwords.
• Replace polling refresh with WebSocket or server-push messaging.
• Add automated tests around JDBC operations with a local test database.
• Move image resizing and file conversion into a reusable media service.
• Add schema SQL as a plain .sql file instead of relying on PDF artifacts.
• Introduce a clearer MVC or service-layer boundary between Swing panels and persistence code.

Authors

Built by Sibei Zhou, Gray Keng, and Lester Li.