SnowflakeAnnotation

SnowflakeAnnotation is a lightweight Java library designed for Spring Boot applications to generate unique, ordered, and distributed IDs. Based on Twitter's Snowflake algorithm, it allows you to automatically populate ID fields in your entity classes using a simple annotation.

Features

• Spring Boot Integration: Quick setup with minimal configuration.

• Annotation-Based: Keeps your business logic clean by using @SnowflakeId to handle ID generation.

• Distributed System Support: Prevents collisions across microservices with Worker ID and Datacenter ID support.

• Time-Ordered: IDs are generated based on timestamps, making them naturally sortable.

• High Performance: Generates IDs at the application level without relying on external database sequences or locks.

Installation

Maven

Add the following dependency to your pom.xml (after installing the library to your local or central repository):

XML

<dependency>
    <groupId>io.github.tolunaym</groupId>
    <artifactId>SnowflakeAnnotation</artifactId>
    <version>1.0.0</version>
</dependency>

Usage

1. Configuration

Define the following properties in your application.properties or application.yml to ensure unique ID generation across different nodes:

Properties

snowflake.worker-id=1
snowflake.datacenter-id=1

You can create your own service to retrieve these values from your environment.

2. Implementation in Entities

Simply add the @SnowflakeId annotation to the field you want and @SnowflakeData to the class you want to be automatically populated:

Java

@SnowflakeData
public class User {

    @SnowflakeId
    private Long id;

    private String username;
    private String email;

    // Getters and Setters
}

3. How it Works

The library intercepts the entity lifecycle (via an Aspect or a pre-persist hook depending on your configuration) and injects a 64-bit unique ID before the object is saved.

ID Structure

The 64-bit ID follows the standard Snowflake structure:

• 1 Bit: Unused (always 0).

• 41 Bits: Timestamp in milliseconds (provides ~69 years of IDs).

• 5 Bits: Datacenter ID.

• 5 Bits: Worker ID.

• 12 Bits: Sequence number (allows 4096 IDs per millisecond per node).

Contributing

Contributions are welcome! If you find a bug or have a feature request, please open an issue or submit a pull request.

License

This project is licensed under the MIT License - see the LICENSE file for details.