打印日志时，项目反应器始终在主线程中运行

Question

我是 Project Reactor 的新手，在研究 Project Reactor 时，我观察到一件事，总是以打印项目主管日志为主要内容。如果 reactor 运行s 不关心线程，那是怎么发生的？以及我如何在不同的不同线程上获得经过验证的反应代码运行？

Answer 1

作为默认 Reactor 运行基于您订阅的线程。如果您从自己的线程订阅，反应堆运行将基于该线程。也就是说不是每次都是主线程。你可以运行这个测试代码来验证。这是在主线程上创建的通量。那个流量是从另一个新创建的线程订阅的。在运行应用程序之后，查看日志。日志会证明这一点。日志已运行在我们新创建的新线程上。

    public void testTheThread() throws InterruptedException {
        //the flux created on the main thread.
        Flux<String> stringFlux = Flux
                .fromArray(new String[]{"a", "b"})
                .map(String::toUpperCase)
                .log();

        //the subscriber runs on another new thread. [my-new-thread]
        Thread newThread = new Thread(() -> {

            stringFlux.subscribe(s -> {
                System.out.println("String is  = " + s);
            });
        });
        newThread.setName("my-new-thread");
        newThread.start();
        //sleep the main thread until get the data from my-new-thread
        //otherwise the log will not be printed.
        Thread.sleep(1000);
    }

日志将是这样的。

17:04:30.867 [my-new-thread] INFO reactor.Flux.MapFuseable.1 - | onSubscribe([Fuseable] FluxMapFuseable.MapFuseableSubscriber)
17:04:30.874 [my-new-thread] INFO reactor.Flux.MapFuseable.1 - | request(unbounded)
17:04:30.874 [my-new-thread] INFO reactor.Flux.MapFuseable.1 - | onNext(A)
s = A
17:04:30.880 [my-new-thread] INFO reactor.Flux.MapFuseable.1 - | onNext(B)
s = B
17:04:30.881 [my-new-thread] INFO reactor.Flux.MapFuseable.1 - | onComplete()

Process finished with exit code 0

打印日志时，项目反应器始终在主线程中运行

project reactor always runs in the main thread when the logs get prints

reactive-programming

project-reactor