context-propagation spring reactor 的上下文传递包

context-propagation 是一个比较强大的上下文传递包，对于上下文处理进行了一些抽象，可以兼容传统ThreadLocal的一些处理

参考玩法

包含了自动模式`Hooks.enableAutomaticContextPropagation();`

static final ThreadLocal<String> TL = new ThreadLocal<>();
    static final String TLKEY = "demo";

    public static void main(String[] args) throws InterruptedException {
        BlockHound.install();
        ReactorDebugAgent.init();
        Hooks.enableAutomaticContextPropagation();
        ContextRegistry.getInstance()
                .registerThreadLocalAccessor(
                        TLKEY,
                        TL::get,
                        TL::set,
                        TL::remove
                );
        TL.set("HELLO");
        var info = Mono.deferContextual(ctx ->
                        Mono.delay(Duration.ofSeconds(1))
                                // we're now in another thread, TL is not explicitly set
                                .map(v -> "delayed ctx[" + TLKEY + "]=" + ctx.getOrDefault(TLKEY, "not found") + ", TL=" + TL.get()))
                .block(); // returns "delayed ctx[TLKEY]=HELLO, TL=null" in default mode
        // returns "delayed ctx[TLKEY]=HELLO, TL=HELLO" in automatic mode
        System.out.println(info);
    }

说明

context-propagation 包是一个比较有用的，尤其在链路追踪场景中

参考资料

https://aabir-hassan.medium.com/demystifying-spring-webflux-the-reactor-context-part-4-3169d02ae2f4

https://docs.micrometer.io/context-propagation/reference/usage.html

https://github.com/micrometer-metrics/context-propagation

https://projectreactor.io/docs/core/3.8.6-SNAPSHOT/reference/advanced-contextPropagation.html