本文整理了Java中io.reactivex.Observable.count()方法的一些代码示例，展示了Observable.count()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Observable.count()方法的具体详情如下：
包路径：io.reactivex.Observable
类名称：Observable
方法名：count

Observable.count介绍

[英]Returns a Single that counts the total number of items emitted by the source ObservableSource and emits this count as a 64-bit Long.

Scheduler: count does not operate by default on a particular Scheduler.
[中]返回对源ObservableSource发出的项目总数进行计数的单个值，并以64位长的形式发出此计数。
计划程序：默认情况下，计数不会在特定计划程序上运行。

代码示例

代码示例来源：origin: ReactiveX/RxJava

@Override
  public SingleSource<Long> apply(Observable<Object> o) throws Exception {
    return o.count();
  }
});

代码示例来源：origin: ReactiveX/RxJava

@Override
  public ObservableSource<Long> apply(Observable<Object> o) throws Exception {
    return o.count().toObservable();
  }
});

代码示例来源：origin: ReactiveX/RxJava

@Test
public void testCountError() {
  Observable<String> o = Observable.error(new Callable<Throwable>() {
    @Override
    public Throwable call() {
      return new RuntimeException();
    }
  });
  o.count().subscribe(wo);
  verify(wo, never()).onSuccess(anyInt());
  verify(wo, times(1)).onError(any(RuntimeException.class));
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void dispose() {
  TestHelper.checkDisposed(Observable.just(1).count());
  TestHelper.checkDisposed(Observable.just(1).count().toObservable());
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void testCountAFewItems() {
  Observable<String> o = Observable.just("a", "b", "c", "d");
  o.count().subscribe(wo);
  // we should be called only once
  verify(wo, times(1)).onSuccess(anyLong());
  verify(wo).onSuccess(4L);
  verify(wo, never()).onError(any(Throwable.class));
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void testCountAFewItemsObservable() {
  Observable<String> o = Observable.just("a", "b", "c", "d");
  o.count().toObservable().subscribe(w);
  // we should be called only once
  verify(w, times(1)).onNext(anyLong());
  verify(w).onNext(4L);
  verify(w, never()).onError(any(Throwable.class));
  verify(w, times(1)).onComplete();
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void testCountErrorObservable() {
  Observable<String> o = Observable.error(new Callable<Throwable>() {
    @Override
    public Throwable call() {
      return new RuntimeException();
    }
  });
  o.count().toObservable().subscribe(w);
  verify(w, never()).onNext(anyInt());
  verify(w, never()).onComplete();
  verify(w, times(1)).onError(any(RuntimeException.class));
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void testCountZeroItems() {
  Observable<String> o = Observable.empty();
  o.count().subscribe(wo);
  // we should be called only once
  verify(wo, times(1)).onSuccess(anyLong());
  verify(wo).onSuccess(0L);
  verify(wo, never()).onError(any(Throwable.class));
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void justUnsubscribed() throws Exception {
  o = new Object();
  WeakReference<Object> wr = new WeakReference<Object>(o);
  TestObserver<Long> to = Observable.just(o).count().toObservable().onTerminateDetach().test();
  o = null;
  to.cancel();
  System.gc();
  Thread.sleep(200);
  Assert.assertNull("Object retained!", wr.get());
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void testCountZeroItemsObservable() {
  Observable<String> o = Observable.empty();
  o.count().toObservable().subscribe(w);
  // we should be called only once
  verify(w, times(1)).onNext(anyLong());
  verify(w).onNext(0L);
  verify(w, never()).onError(any(Throwable.class));
  verify(w, times(1)).onComplete();
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void just() throws Exception {
  o = new Object();
  WeakReference<Object> wr = new WeakReference<Object>(o);
  TestObserver<Object> to = new TestObserver<Object>();
  Observable.just(o).count().toObservable().onTerminateDetach().subscribe(to);
  to.assertValue(1L);
  to.assertComplete();
  to.assertNoErrors();
  o = null;
  System.gc();
  Thread.sleep(200);
  Assert.assertNull("Object retained!", wr.get());
}

代码示例来源：origin: Polidea/RxAndroidBle

/**
 * Observable that emits `true` if the permission was granted on the time of subscription
 * @param locationServicesStatus the LocationServicesStatus
 * @param timerScheduler the Scheduler
 * @return the observable
 */
@NonNull
private static Single<Boolean> checkPermissionUntilGranted(
    final LocationServicesStatus locationServicesStatus,
    Scheduler timerScheduler
) {
  return Observable.interval(0, 1L, TimeUnit.SECONDS, timerScheduler)
      .takeWhile(new Predicate<Long>() {
        @Override
        public boolean test(Long timer) {
          return !locationServicesStatus.isLocationPermissionOk();
        }
      })
      .count()
      .map(new Function<Long, Boolean>() {
        @Override
        public Boolean apply(Long count) throws Exception {
          // if no elements were emitted then the permission was granted from the beginning
          return count == 0;
        }
      });
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void testTakeLastZeroProcessesAllItemsButIgnoresThem() {
  final AtomicInteger upstreamCount = new AtomicInteger();
  final int num = 10;
  long count = Observable.range(1, num).doOnNext(new Consumer<Integer>() {
    @Override
    public void accept(Integer t) {
      upstreamCount.incrementAndGet();
    }})
    .takeLast(0).count().blockingGet();
  assertEquals(num, upstreamCount.get());
  assertEquals(0L, count);
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void fromArityArgs1() {
  Observable<String> items = Observable.just("one");
  assertEquals((Long)1L, items.count().blockingGet());
  assertEquals("one", items.takeLast(1).blockingSingle());
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void testUpstreamIsProcessedButIgnoredObservable() {
  final int num = 10;
  final AtomicInteger upstreamCount = new AtomicInteger();
  long count = Observable.range(1, num)
      .doOnNext(new Consumer<Integer>() {
        @Override
        public void accept(Integer t) {
          upstreamCount.incrementAndGet();
        }
      })
      .ignoreElements()
      .toObservable()
      .count().blockingGet();
  assertEquals(num, upstreamCount.get());
  assertEquals(0, count);
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void fromIterable() {
  ArrayList<String> items = new ArrayList<String>();
  items.add("one");
  items.add("two");
  items.add("three");
  assertEquals((Long)3L, Observable.fromIterable(items).count().blockingGet());
  assertEquals("two", Observable.fromIterable(items).skip(1).take(1).blockingSingle());
  assertEquals("three", Observable.fromIterable(items).takeLast(1).blockingSingle());
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void testIssue1522() {
  // https://github.com/ReactiveX/RxJava/issues/1522
  assertNull(Observable
      .empty()
      .count()
      .filter(new Predicate<Long>() {
        @Override
        public boolean test(Long v) {
          return false;
        }
      })
      .blockingGet());
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void fromArityArgs3() {
  Observable<String> items = Observable.just("one", "two", "three");
  assertEquals((Long)3L, items.count().blockingGet());
  assertEquals("two", items.skip(1).take(1).blockingSingle());
  assertEquals("three", items.takeLast(1).blockingSingle());
}

代码示例来源：origin: ReactiveX/RxJava

@Test
public void fromArray() {
  String[] items = new String[] { "one", "two", "three" };
  assertEquals((Long)3L, Observable.fromArray(items).count().blockingGet());
  assertEquals("two", Observable.fromArray(items).skip(1).take(1).blockingSingle());
  assertEquals("three", Observable.fromArray(items).takeLast(1).blockingSingle());
}

代码示例来源：origin: silentbalanceyh/vertx-zero

private boolean isPlugin(final Class<?> clazz) {
    final Field[] fields = clazz.getDeclaredFields();
    final Long counter = Observable.fromArray(fields)
        .filter(field -> field.isAnnotationPresent(Plugin.class))
        .count().blockingGet();
    return 0 < counter;
  }
}