Question

这是一个简单的spring boot应用程序：

@SpringBootApplication
@RestController
public class ReactiveApplication {

    static Flux<String> fluxString;
    static volatile Queue<String> queue = new ConcurrentLinkedQueueProxy();

    private static class ConcurrentLinkedQueueProxy extends ConcurrentLinkedQueue<String> {
        private static final long serialVersionUID = 1L;

        @Override
        public boolean add(String e) {
            synchronized (this) {
                notify();
            }
            return super.add(e);
        }

        @Override
        public String poll() {
            synchronized (this) {
                if(isEmpty()) {
                    try {
                        wait();
                    } catch (InterruptedException ex) {}
                }
            }
            return super.peek() == null ? "" : super.poll();
        }
    }

    static Consumer<String> consumer = str -> queue.add(str);

    public static void main(String[] args) throws InterruptedException {
        SpringApplication.run(ReactiveApplication.class, args);
    }

    static {
        for(int i = 0; i < 10; i++)
            queue.add("testData " + i + " ");
    }

    @GetMapping(value = "/", produces = MediaType.APPLICATION_STREAM_JSON_VALUE)
    public Flux<String> home() {

        Scheduler sch = Schedulers.newParallel("parallel-sch", 1);
        List<String> list = new ArrayList<>(queue);
        queue.removeAll(queue);

        fluxString = Flux.<String>create(sink -> {
            sink.onRequest(n -> {
                for(int i = 0; i < n; i++) {
                    sink.next(queue.poll());
                }
            }).onCancel(() -> sch.dispose());
        }).log().subscribeOn(sch).mergeWith(Flux.<String>fromIterable(list));

        return fluxString;

    }

    @GetMapping("/add")
    public String add( @RequestParam String s) {
        consumer.accept(s);
        return s;
    }

}

因此，基本上，此应用程序创建一个String流。访问/将抢占所有存在的字符串队列，然后合并从/add资源中添加的所有内容（忽略“安全方法必须是幂等”）。

我感到奇怪的是，当我将public static void main(...)移动到第1行时，应用程序开始行为异常，并且向/add添加新值没有任何效果。我认为一定有一些有趣的事情正在导致应用程序行为异常。有什么解释吗？

Answer 1

我最终使用了它，效果很好：

@SpringBootApplication
@RestController
public class ReactiveApplication {

    private static BlockingQueue<String> queue = new ArrayBlockingQueue<>(1000);
    private static Consumer<String> consumer = str -> {
        try { queue.put(str); }
        catch (InterruptedException e) {}
    };
    static {
        for (int i = 0; i < 10; i++) queue.add("testData " + i + " ");
    }

    public static void main(String[] args) {
        SpringApplication.run(ReactiveApplication.class, args);
    }

    @GetMapping(value = "/", produces = MediaType.APPLICATION_STREAM_JSON_VALUE)
    public Flux<String> home() {

        final Scheduler sch = Schedulers.newSingle("async-flux");

        return Flux.<String>generate(sink -> {
            try { sink.next(queue.take()); }
            catch (InterruptedException e) { }
        }).log().subscribeOn(sch);

    }

    @GetMapping("/add")
    public String add(@RequestParam String s) {
        consumer.accept(s);
        return s;
    }

}

春季WebFlux消费者沉没

1 个答案: