Knowledge Engine — Personal Search & Knowledge Management System

A full-stack, portfolio-quality personal knowledge base and search engine built with Java/Spring Boot, PostgreSQL, and React.

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Architecture

knowledge-engine/
├── backend/          → Spring Boot REST API (Java 21, Maven)
├── frontend/         → React SPA (Vite)
└── README.md

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Tech Stack

Layer	Technology
Backend	Java 21, Spring Boot 3.x, Maven
Database	PostgreSQL 15+ (with full-text search)
Frontend	React 18, Vite, React Router v6
HTTP Client	Axios
Migrations	Flyway
Styling	CSS Modules + CSS Variables

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Prerequisites

• Java 21+
• Node.js 18+
• PostgreSQL 15+
• Maven 3.8+

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Database Setup

-- Run as postgres superuser
CREATE DATABASE knowledge_engine;
CREATE USER ke_user WITH ENCRYPTED PASSWORD 'ke_password';
GRANT ALL PRIVILEGES ON DATABASE knowledge_engine TO ke_user;

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Backend Setup

cd backend

# Copy and configure environment
cp src/main/resources/application.properties.example src/main/resources/application.properties
# Edit application.properties with your DB credentials

# Run (Flyway will auto-apply migrations)
mvn spring-boot:run

Backend starts on http://localhost:8080

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Frontend Setup

cd frontend
npm install
npm run dev

Frontend starts on http://localhost:5173

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API Reference

Documents

Method	Endpoint	Description
GET	/api/documents	List all (paginated)
GET	/api/documents/{id}	Get single document
POST	/api/documents	Create document
PUT	/api/documents/{id}	Update document
DELETE	/api/documents/{id}	Delete document
GET	/api/documents/search	Search (q, tags, sort, page)

Tags

Method	Endpoint	Description
GET	/api/tags	List all tags
POST	/api/tags	Create tag
DELETE	/api/tags/{id}	Delete tag

Query Parameters for /api/documents and /api/documents/search

Param	Type	Description
q	string	Full-text search query
tags	string	Comma-separated tag names
page	int	Page number (0-indexed, default: 0)
size	int	Page size (default: 10, max: 50)
sort	string	Field to sort by (createdAt, title)
dir	string	Sort direction: asc / desc