Process Orchestration and Plugin Extension for Business Isolation and Extensibility in Backend Systems

As a seasoned developer, the author stresses the importance of keeping solutions simple and avoiding over‑design, especially when handling multiple business lines that would otherwise lead to tangled if‑else statements.

Initially skeptical about workflow orchestration, the author realized its necessity in a middle‑platform team where each business requires isolated and extensible handling without breaking existing functionality.

Key problems identified include code isolation and business extension points, which can be addressed by two main mechanisms:

Using a flow engine to configure distinct execution chains for different business scenarios.

Employing a plugin extension engine to implement business‑specific variations.

The open‑source MemberClub project on Gitee demonstrates these solutions. It provides a paid‑membership transaction platform with various purchase scenarios, showcasing how to integrate SpringBoot with numerous components such as MyBatis‑Plus, ShardingSphere, Redis, Apollo, Spring Cloud, RabbitMQ, H2, Swagger, Lombok, and MapStruct.

Configuring Flow Execution Chains

Different membership products require distinct purchase processes, so the class DemoMemberPurchaseExtension defines three flow‑chain configurations, as illustrated in the accompanying screenshot.

Defining Flow Nodes

Each flow node implements the methods process , success , rollback , and callback to handle execution, success handling, error recovery, and final callbacks.

Flow Execution

To run a flow, provide a context object and invoke FlowChain.execute . The engine links nodes in a chain, executing each process method sequentially. If a process throws an exception, the engine triggers rollback on already‑executed nodes; otherwise, it calls success in reverse order, followed by callback for all nodes.

Flow Engine Execution Principle

The core implementation of FlowChain.execute is shown below:

public <T> void execute(FlowChain<T> chain, T context) { 
    Exception exception = null; 
    int index = -1; 
    for (FlowNode<T> node : chain.getNodes()) { 
        try { 
            node.process(context); 
            index++; 
        } catch (Exception e) { 
            if (e instanceof SkipException) { 
                CommonLog.warn("当前流程:{} 发出 Skip请求,后续流程不再执行", node.getClass().getSimpleName()); 
                break; 
            } 
            exception = e; 
            break; 
        } 
    } 
    if (exception != null) { 
        for (int i = index; i >= 0; i--) { 
            FlowNode<T> node = chain.getNodes().get(i); 
            try { 
                node.rollback(context, exception); 
            } catch (Exception e) { 
                CommonLog.error("rollback执行异常,忽略 name:{}", node.getClass().getSimpleName(), e); 
            } 
        } 
    } else { 
        for (int i = index; i >= 0; i--) { 
            FlowNode<T> node = chain.getNodes().get(i); 
            try { 
                node.success(context); 
            } catch (Exception e) { 
                CommonLog.error("success 执行异常,忽略 name:{}", node.getClass().getSimpleName(), e); 
            } 
        } 
    } 
    for (int i = index; i >= 0; i--) { 
        FlowNode<T> node = chain.getNodes().get(i); 
        try { 
            node.callback(context, exception); 
        } catch (Exception e) { 
            CommonLog.error("callback执行异常,忽略 name:{}", node.getClass().getSimpleName(), e); 
        } 
    } 
    if (exception != null) { 
        throw exception; 
    } 
}

The full source code is available in the MemberClub repository.

https://gitee.com/juejinwuyang/memberclub

MemberClub is an open‑source project that provides a comprehensive paid‑membership transaction solution, making it an excellent reference for learning middle‑platform architecture, workflow management, and various supporting components such as distributed retry, logging, inventory, distributed locks, Redis Lua scripts, and Spring context utilities.

Source links:

Gitee: https://gitee.com/juejinwuyang/memberclub

GitHub: https://github.com/juejin-wuyang/memberclub