fix: prioerity queue issue

Author: sonus21

README.md

@@ -1,17 +1,17 @@
 <div>
    <img  align="left" src="https://raw.githubusercontent.com/sonus21/rqueue/master/rqueue-core/src/main/resources/public/rqueue/img/android-chrome-192x192.png" alt="Rqueue Logo" width="90">
-   <h1 style="float:left">Rqueue: Redis-Backed Job Queue and Scheduler for Spring and Spring Boot</h1>
+   <h1 style="float:left">Rqueue: Job Queue and Scheduler for Spring and Spring Boot (Redis &amp; NATS)</h1>
 </div>
 
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 [![Maven Central](https://img.shields.io/maven-central/v/com.github.sonus21/rqueue-core)](https://repo1.maven.org/maven2/com/github/sonus21/rqueue-core)
 [![Javadoc](https://javadoc.io/badge2/com.github.sonus21/rqueue-core/javadoc.svg)](https://javadoc.io/doc/com.github.sonus21/rqueue-core)
 [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](LICENSE)
 
-**Rqueue** is a Redis-backed job queue and producer-consumer system for Spring and Spring Boot. It
-supports both producers and consumers for background jobs, scheduled tasks, and event-driven
-workflows, similar to Sidekiq or Celery, but fully integrated into the Spring programming model with
-annotation-driven APIs and minimal setup.
+**Rqueue** is a job queue and producer-consumer system for Spring and Spring Boot with pluggable
+broker backends — **Redis** (default) and **NATS JetStream**. It supports producers and consumers
+for background jobs, scheduled tasks, and event-driven workflows, similar to Sidekiq or Celery,
+fully integrated into the Spring programming model with annotation-driven APIs and minimal setup.
 
 <br/>
 
@@ -49,19 +49,21 @@ annotation-driven APIs and minimal setup.
   * Monitor in-flight, queued, and scheduled messages with metrics
   * Use the built-in web dashboard for queue visibility and latency insights
 
-* **Redis and platform support**
+* **Backend and platform support**
+  * Switch backends with a single property (`rqueue.backend=redis|nats`)
   * Use a separate Redis setup for Rqueue if needed
   * Support Redis standalone, Sentinel, and Cluster setups
   * Work with Lettuce for Redis Cluster
   * Support reactive Redis and Spring WebFlux
+  * Use NATS JetStream as a drop-in Redis replacement (add `rqueue-nats` and set `rqueue.backend=nats`)
 
 ### Requirements
 
 * Spring 5+, 6+, 7+
-* Java 1.8+,17, 21
-* Spring boot 2+,3+,4+
-* Lettuce client for Redis cluster
-* Read master preference for Redis cluster
+* Java 1.8+, 17, 21
+* Spring Boot 2+, 3+, 4+
+* **Redis backend (default):** Lettuce client; read-master preference for Redis Cluster
+* **NATS backend:** NATS Server 2.2+ with JetStream enabled (`nats-server -js`); `rqueue-nats` on the classpath
 
 ## Getting Started
 
@@ -95,6 +97,40 @@ from [Maven central](https://search.maven.org/search?q=g:com.github.sonus21%20AN
 
   No additional configurations are required, only dependency is required.
 
+##### Spring Boot with NATS backend
+
+To use NATS JetStream instead of Redis, add `rqueue-nats` alongside the starter and set
+`rqueue.backend=nats` in `application.properties`:
+
+* Gradle
+  ```groovy
+  implementation 'com.github.sonus21:rqueue-spring-boot-starter:4.0.0-RELEASE'
+  implementation 'com.github.sonus21:rqueue-nats:4.0.0-RELEASE'
+  ```
+* Maven
+  ```xml
+  <dependency>
+      <groupId>com.github.sonus21</groupId>
+      <artifactId>rqueue-spring-boot-starter</artifactId>
+      <version>4.0.0-RELEASE</version>
+  </dependency>
+  <dependency>
+      <groupId>com.github.sonus21</groupId>
+      <artifactId>rqueue-nats</artifactId>
+      <version>4.0.0-RELEASE</version>
+  </dependency>
+  ```
+
+Then in `application.properties`:
+```properties
+rqueue.backend=nats
+rqueue.nats.connection.url=nats://localhost:4222
+```
+
+No `RedisConnectionFactory` bean is required. Start a JetStream-enabled NATS server with
+`nats-server -js` and the application is ready. See the [NATS backend](#nats-backend) section
+below for streams, KV buckets, and advanced configuration.
+
 ---
 
 #### Spring Framework

docs/index.md

@@ -2,18 +2,19 @@
 layout: default
 title: Home
 nav_order: 1
-description: Rqueue Redis Based Async Message Processor
+description: Rqueue Job Queue and Scheduler for Spring — Redis and NATS JetStream backends
 permalink: /
 ---
 
-# Rqueue | Redis-Backed Job Queue and Scheduler For Spring Framework
+# Rqueue | Job Queue and Scheduler For Spring Framework (Redis & NATS)
 
 {: .fs-4 }
 
-Rqueue is a Redis-backed job queue and producer-consumer system for Spring and Spring Boot. It
-supports both producers and consumers for background jobs, scheduled tasks, and event-driven
-workflows, similar to Sidekiq or Celery, while staying fully integrated with the Spring programming
-model through annotation-driven APIs and minimal setup.
+Rqueue is a job queue and producer-consumer system for Spring and Spring Boot with pluggable
+broker backends — **Redis** (default) and **NATS JetStream**. It supports producers and consumers
+for background jobs, scheduled tasks, and event-driven workflows, similar to Sidekiq or Celery,
+while staying fully integrated with the Spring programming model through annotation-driven APIs
+and minimal setup.
 
 {: .fs-6 .fw-300 }
 
@@ -55,19 +56,21 @@ model through annotation-driven APIs and minimal setup.
   * Use the built-in web dashboard for queue visibility, worker activity, and message operations
   * Override message ID generation with a custom `RqueueMessageIdGenerator` bean
 
-* **Redis and platform support**
+* **Backend and platform support**
+  * Switch backends with a single property (`rqueue.backend=redis|nats`)
   * Support Redis standalone, Sentinel, and Cluster setups
   * Support reactive Redis and Spring WebFlux
   * Keep Redis configuration flexible for different deployment models
+  * Use NATS JetStream as a drop-in Redis replacement (add `rqueue-nats` and set `rqueue.backend=nats`)
 
 ### Requirements
 
 * Spring 6+, 7+
 * Spring Boot 3+, 4+
 * Java 21+
 * Spring Reactive
-* Lettuce client for Redis cluster
-* Read master preference for Redis cluster
+* **Redis backend (default):** Lettuce client; read-master preference for Redis Cluster
+* **NATS backend:** NATS Server 2.2+ with JetStream enabled (`nats-server -js`); `rqueue-nats` on the classpath
 
 ## Getting Started
 
@@ -80,7 +83,8 @@ inconsistencies. Queues should **only** be created when using Rqueue as a produc
 {: .highlight }
 The Rqueue GitHub repository includes several sample applications for local testing and demonstration:
 
-* [Rqueue Spring Boot Example](https://github.com/sonus21/rqueue/tree/master/rqueue-spring-boot-example)
+* [Rqueue Spring Boot Example](https://github.com/sonus21/rqueue/tree/master/rqueue-spring-boot-example) — Redis backend
+* [Rqueue Spring Boot NATS Example](https://github.com/sonus21/rqueue/tree/master/rqueue-spring-boot-nats-example) — NATS JetStream backend
 * [Rqueue Spring Boot Reactive Example](https://github.com/sonus21/rqueue/tree/master/rqueue-spring-boot-reactive-example)
 * [Rqueue Spring Example](https://github.com/sonus21/rqueue/tree/master/rqueue-spring-example)
 
@@ -161,6 +165,69 @@ public class Application {
 
 ---
 
+### NATS JetStream Backend
+
+To use NATS JetStream instead of Redis, add `rqueue-nats` alongside the starter and set
+`rqueue.backend=nats`. No `RedisConnectionFactory` bean is required.
+
+{: .warning }
+The NATS backend does not support delayed enqueue, scheduled messages, or cron jobs (`enqueueIn`,
+`enqueueAt`, `enqueuePeriodic`). These throw `UnsupportedOperationException`. Use the Redis
+backend for workloads that require scheduling.
+
+#### Spring Boot 4.x — NATS Setup
+
+* Gradle
+  ```groovy
+  implementation 'com.github.sonus21:rqueue-spring-boot-starter:4.0.0-RELEASE'
+  implementation 'com.github.sonus21:rqueue-nats:4.0.0-RELEASE'
+  ```
+
+* Maven
+  ```xml
+  <dependency>
+      <groupId>com.github.sonus21</groupId>
+      <artifactId>rqueue-spring-boot-starter</artifactId>
+      <version>4.0.0-RELEASE</version>
+  </dependency>
+  <dependency>
+      <groupId>com.github.sonus21</groupId>
+      <artifactId>rqueue-nats</artifactId>
+      <version>4.0.0-RELEASE</version>
+  </dependency>
+  ```
+
+Then in `application.properties`:
+
+```properties
+rqueue.backend=nats
+rqueue.nats.connection.url=nats://localhost:4222
+```
+
+Start a JetStream-enabled NATS server:
+
+```sh
+# native binary
+nats-server -js
+
+# Docker
+docker run -p 4222:4222 nats:latest -js
+```
+
+Rqueue provisions streams and KV buckets at startup. For locked-down JetStream accounts where the
+application credentials cannot call `add_stream` / `kv_create` at runtime, set:
+
+```properties
+rqueue.nats.auto-create-streams=false
+rqueue.nats.auto-create-kv-buckets=false
+```
+
+…and pre-create the streams and buckets before starting the application. See the
+[rqueue-spring-boot-nats-example](https://github.com/sonus21/rqueue/tree/master/rqueue-spring-boot-nats-example)
+for a complete working example and the repository README for the full stream / KV bucket reference.
+
+---
+
 {: .highlight }
 
 Once Rqueue is configured, you can use its methods and annotations consistently