Executor

A Spring Boot demo that processes CSV uploads using Java's ExecutorService and Spring's ThreadPoolTaskExecutor, exposing REST endpoints that run the same workload single-threaded, multi-threaded (parallel), and asynchronously with task-status polling.

Features

• Single-threaded (synchronous) CSV processing endpoint
• Multi-threaded parallel CSV processing endpoint
• Asynchronous CSV processing with a task id returned immediately
• Task-status polling endpoint backed by a database table
• Configurable ThreadPoolTaskExecutor (core/max pool size, queue capacity)
• CSV parsing via univocity-parsers and persistence via Spring Data JPA

Tech Stack

• Java 17
• Spring Boot 2.7.18 (spring-boot-starter-web, spring-boot-starter-data-jpa)
• univocity-parsers 2.9.1 (CSV parsing)
• MySQL (mysql-connector-j) with HikariCP
• Lombok
• Gradle

Getting Started

Prerequisites

• JDK 17
• A running MySQL instance with a schema matching the configured datasource URL

Build and Run

./gradlew bootRun

The application starts on port 8080 with context path /executor, so endpoints are served under http://localhost:8080/executor.

To build a jar:

./gradlew build

Configuration

Configuration lives in src/main/resources/application.properties:

server.port=8080
server.servlet.context-path=/executor

spring.datasource.url=jdbc:mysql://<DB_HOST>:<DB_PORT>/<DB_NAME>?allowPublicKeyRetrieval=true&useSSL=false
spring.datasource.username=<DB_USERNAME>
spring.datasource.password=<DB_PASSWORD>
spring.jpa.hibernate.ddl-auto=update

## Thread pool executor configs
thread.executor.core.pool.size=4
thread.executor.max.pool.size=6
thread.executor.queue.capacity=20

Usage

All upload endpoints accept a JSON body wrapping an UploadRequest that carries the CSV file path:

{
  "data": {
    "path": "/absolute/path/to/file.csv"
  }
}

Endpoints

• POST /executor/v1/task/upload/single — process the CSV in a single thread (synchronous)
• POST /executor/v1/task/upload/multi — process the CSV across multiple parallel threads (synchronous)
• POST /executor/v1/task/upload/async — process the CSV asynchronously; returns a task id
• GET /executor/v1/task/status?task_id=<id> — poll the status of an asynchronous task