SimpleTimer is a lightweight, high-performance distributed timer service built with Kotlin and Netty. It provides scheduled task execution with topic-based message publishing and subscription functionality.
- 🚀 High Performance: Built on Netty for excellent network performance
- ⏰ Delayed Task Scheduling: Schedule tasks to execute after a specified delay
- 📡 Topic-based Pub/Sub: Support for topic-based message publishing and subscription
- 💓 Heartbeat Mechanism: Built-in heartbeat for connection health monitoring
- 🔄 Automatic Cleanup: Automatic cleanup of timeout channels
- 🛡️ Thread Safe: Concurrent-safe operations using ConcurrentHashMap
The project consists of several key components:
- SimplerTimer: Main server class that manages Netty server bootstrap
- TopicManager: Manages topic subscriptions and message publishing
- ScheduleTaskProcessor: Handles delayed task scheduling using HashedWheelTimer
- Message Protocol: Custom binary protocol for client-server communication
- Network Layer: Message encoding/decoding and channel management
- PING/PONG (Type 1): Heartbeat messages for connection health
- Schedule Task (Type 2): Schedule a delayed task
- Triggered (Type 3): Notification when a scheduled task is triggered
- Java 21 or higher
- Gradle 7.0 or higher
# Clone the repository
git clone <repository-url>
cd SimpleTimer
# Build the project
./gradlew build
# Run the server (default port: 8080)
./gradlew run
# Or build and run the JAR
./gradlew shadowJar
java -jar build/libs/SimpleTimer-dev.jarThe server starts on port 8080 by default. You can modify the port in TimerStarter.kt:
fun main() = SimplerTimer().run(8081) // Custom portThe server accepts binary messages with the following protocol:
Message Structure:
- Magic Number (4 bytes): 0x7355608
- Version (4 bytes): 1
- Type (4 bytes): Message type (1=PING/PONG, 2=Schedule, 3=Triggered)
- Topic Length (4 bytes): Length of topic string
- Topic (variable): Topic name
- Delay (8 bytes): Delay in milliseconds
- Payload (variable): Message payload
- Netty 4.2.4.Final: High-performance network framework
- SLF4J 2.0.17: Logging facade
- Logback 1.5.18: Logging implementation
- Kotlin 2.2.0: Programming language
- Fork the repository
- Create a feature branch
- Commit your changes
- Push to the branch
- Create a Pull Request
This project is open source. Please check the license file for details.
A cross-platform open source client library is available for SimpleTimer:
This library makes it easy to connect to the SimpleTimer server, schedule tasks, and subscribe to topics from your own applications.
SimpleTimer 是一个基于 Kotlin 和 Netty 构建的轻量级、高性能分布式定时器服务。它提供延时任务执行功能，并支持基于主题的消息发布订阅。
- 🚀 高性能: 基于 Netty 构建，提供卓越的网络性能
- ⏰ 延时任务调度: 支持指定延时后执行的任务调度
- 📡 基于主题的发布订阅: 支持基于主题的消息发布和订阅功能
- 💓 心跳机制: 内置心跳机制用于连接健康监控
- 🔄 自动清理: 自动清理超时的连接通道
- 🛡️ 线程安全: 使用 ConcurrentHashMap 确保并发安全操作
项目由以下核心组件组成：
- SimplerTimer: 主服务器类，管理 Netty 服务器启动
- TopicManager: 管理主题订阅和消息发布
- ScheduleTaskProcessor: 使用 HashedWheelTimer 处理延时任务调度
- 消息协议: 客户端-服务器通信的自定义二进制协议
- 网络层: 消息编码/解码和通道管理
- PING/PONG (类型 1): 用于连接健康检查的心跳消息
- 调度任务 (类型 2): 调度一个延时任务
- 任务触发 (类型 3): 计划任务被触发时的通知
- Java 21 或更高版本
- Gradle 7.0 或更高版本
# 克隆仓库
git clone <repository-url>
cd SimpleTimer
# 构建项目
./gradlew build
# 运行服务器（默认端口：8080）
./gradlew run
# 或者构建并运行 JAR 包
./gradlew shadowJar
java -jar build/libs/SimpleTimer-dev.jar服务器默认在 8080 端口启动。你可以在 TimerStarter.kt 中修改端口：
fun main() = SimplerTimer().run(8081) // 自定义端口服务器接受以下协议的二进制消息：
消息结构:
- 魔数 (4 字节): 0x7355608
- 版本 (4 字节): 1
- 类型 (4 字节): 消息类型 (1=PING/PONG, 2=调度, 3=触发)
- 主题长度 (4 字节): 主题字符串的长度
- 主题 (可变): 主题名称
- 延时 (8 字节): 延时时间（毫秒）
- 负载 (可变): 消息负载
- Netty 4.2.4.Final: 高性能网络框架
- SLF4J 2.0.17: 日志门面
- Logback 1.5.18: 日志实现
- Kotlin 2.2.0: 编程语言
- Fork 本仓库
- 创建功能分支
- 提交你的修改
- 推送到分支
- 创建 Pull Request
本项目为开源项目。详细信息请查看许可证文件。
SimpleTimer 提供了跨平台的开源客户端库，方便你的应用程序接入定时器服务：
该库支持连接 SimpleTimer 服务器、任务调度和主题订阅等功能。