src/main/java/io/reactivex/Flowable.java
@CheckReturnValue
    @NonNull
    @BackpressureSupport(BackpressureKind.PASS_THROUGH)
    @SchedulerSupport(SchedulerSupport.NONE)
    private Flowable<T> doOnEach(Consumer<? super T> onNext, Consumer<? super Throwable> onError,
            Action onComplete, Action onAfterTerminate) {
        ObjectHelper.requireNonNull(onNext, "onNext is null");
        ObjectHelper.requireNonNull(onError, "onError is null");
        ObjectHelper.requireNonNull(onComplete, "onComplete is null");
        ObjectHelper.requireNonNull(onAfterTerminate, "onAfterTerminate is null");
        return RxJavaPlugins.onAssembly(new FlowableDoOnEach<T>(this, onNext, onError, onComplete, onAfterTerminate));
    }
@CheckReturnValue
    @NonNull
    @BackpressureSupport(BackpressureKind.PASS_THROUGH)
    @SchedulerSupport(SchedulerSupport.NONE)
    private Flowable<T> doOnEach(Consumer<? super T> onNext, Consumer<? super Throwable> onError,
            Action onComplete, Action onAfterTerminate) {
        ObjectHelper.requireNonNull(onNext, "onNext is null");
        ObjectHelper.requireNonNull(onError, "onError is null");
        ObjectHelper.requireNonNull(onComplete, "onComplete is null");
        ObjectHelper.requireNonNull(onAfterTerminate, "onAfterTerminate is null");
        return RxJavaPlugins.onAssembly(new FlowableDoOnEach<T>(this, onNext, onError, onComplete, onAfterTerminate));
    }
@ CheckReturnValue @ NonNull @ BackpressureSupport ( BackpressureKind . PASS_THROUGH ) @ SchedulerSupport ( SchedulerSupport . NONE ) private Flowable < T > doOnEach ( Consumer < ? super T > onNext , Consumer < ? super Throwable > onError , Action onComplete , Action onAfterTerminate ) { ObjectHelper . requireNonNull ( onNext , "onNext is null" ) ; ObjectHelper . requireNonNull ( onError , "onError is null" ) ; ObjectHelper . requireNonNull ( onComplete , "onComplete is null" ) ; ObjectHelper . requireNonNull ( onAfterTerminate , "onAfterTerminate is null" ) ; return RxJavaPlugins . onAssembly ( new FlowableDoOnEach < T > ( this , onNext , onError , onComplete , onAfterTerminate ) ) ; }
Calls the appropriate onXXX consumer (shared between all subscribers) whenever a signal with the same type
passes through, before forwarding them to downstream.
<p>
<img width="640" height="310" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/doOnEach.png" alt="">
<dl>
<dt><b>Backpressure:</b></dt>
<dd>The operator doesn't interfere with backpressure which is determined by the source {@code Publisher}'s
backpressure behavior.</dd>
<dt><b>Scheduler:</b></dt>
<dd>{@code doOnEach} does not operate by default on a particular {@link Scheduler}.</dd>
</dl>

@return the source Publisher with the side-effecting behavior applied
@see <a href="http://reactivex.io/documentation/operators/do.html">ReactiveX operators documentation: Do</a>
Calls the appropriate onXXX consumer ( shared between all subscribers ) whenever a signal with the same type passes through before forwarding them to downstream . <p > <img width = 640 height = 310 src = https : // raw . github . com / wiki / ReactiveX / RxJava / images / rx - operators / doOnEach . png alt = > <dl > <dt > <b > Backpressure : < / b > < / dt > <dd > The operator doesn t interfere with backpressure which is determined by the source { @code Publisher } s backpressure behavior . < / dd > <dt > <b > Scheduler : < / b > < / dt > <dd > { @code doOnEach } does not operate by default on a particular { @link Scheduler } . < / dd > < / dl >