- Mobikul

RxJava is a Java VM implementation of ReactiveX (Reactive Extensions): a library for composing asynchronous and event-based programs by using observable sequences.

The build blocks for RxJava code are the following:

observables representing sources of data
subscribers (or observers) listening to the observables
a set of methods for modifying and composing the data

Add dependency for Rx java in build.gradle.

compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
compile 'io.reactivex.rxjava2:rxjava:2.1.0'

1 2	compile 'io.reactivex.rxjava2:rxandroid:2.0.1' compile 'io.reactivex.rxjava2:rxjava:2.1.0'

Observable just produces an Observable that emits a single generic instance. For example:

Observable<String> observable = Observable.create(new ObservableOnSubscribe<String>() {
    @Override
    public void subscribe(@NonNull ObservableEmitter<String> e) throws Exception {
         e.onNext("hello");
        e.onNext("world");
    }
});

Observable<String> observable = Observable.create(new ObservableOnSubscribe<String>() {

@Override

public void subscribe(@NonNull ObservableEmitter<String> e) throws Exception {

e.onNext("hello");

e.onNext("world");

}

});

Create an instance of Observer to get the data from the data source (Observable). The data source push data to onNext() method in the observer.

Observer<String> observer = new Observer<String>() {
    @Override
    public void onSubscribe(@NonNull Disposable d) {
        Log.d(TAG, "onSubscribe: "+d);
    }

    @Override
    public void onNext(@NonNull String integer) {
        Log.d(TAG, "onNext: "+integer);
    }

    @Override
    public void onError(@NonNull Throwable e) {
        Log.d(TAG, "onError: "+e);
    }

    @Override
    public void onComplete() {
        Log.d(TAG, "onComplete: "+"DONE ALL WORK RXJAVA");
    }
};

Observer<String> observer = new Observer<String>() {

@Override

public void onSubscribe(@NonNull Disposable d) {

Log.d(TAG, "onSubscribe: "+d);

}

@Override

public void onNext(@NonNull String integer) {

Log.d(TAG, "onNext: "+integer);

}

@Override

public void onError(@NonNull Throwable e) {

Log.d(TAG, "onError: "+e);

}

@Override

public void onComplete() {

Log.d(TAG, "onComplete: "+"DONE ALL WORK RXJAVA");

}

};

Once the observable instance initialised subscribe the observer.

observable.subscribe(observer);

1	observable.subscribe(observer);

OUTPUT: hello world

Advantages of RxJava

Some advantages of RxJava are the following:

You can chain async operations, e.g., if a API call depends on the call of another API
A defined way to handle errors
It reduces the need for state variables, which can be the source of errors == Creating sources, subscribing to them and disposing them

manish choudhary

5 Jul, 2017
Created by - manish choudhary

. . .

OUTPUT: hello world

Advantages of RxJava

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