RXJAVA technical principle detailed explanation
Rxjava technical principle detailed explanation
RXJAVA is a Java programming library based on responsive programming ideas that can simplify asynchronous event processing and event flow -based programming model.RXJAVA is based on the observer mode and iterator mode, and provides rich operators and thread schedurs to facilitate handling and combining asynchronous events.
The core principle of RXJAVA is based on Observable and Observer.Observable represents an observed event source that can emit 0 or more events (including data, errors and completion signals).Observer represents an observer, which is used to subscribe to ObserVable and receive and processes the incidents of ObserVable launch.
The process of using rxjava for event processing is as follows:
1. Create Observable: Create an Observable object through Observable.create () method, and define how it launch an event stream.
2. Subscribe to Observable: Use observable.subscribe () method to subscribe to ObserVable to receive event streams for incident emitted from Observable.
3. Processing event: Observer implement the necessary methods to handle events emitted by ObserVable, such as onnext () to handle data events, onerRor () to handle error events, onComplete () to process completion events.
RXJAVA enriches the processing ability of the event flow through the operator. Common operators include MAP, Filter, Take, etc.These operators can transform, filter, and group operations such as the event flow, so as to achieve more flexible and complex event processing logic.
RXJAVA also provides a thread scheduler to simplify asynchronous incident processing.By using the static method of the Schedulers class, you can switch the ObserVable event flow to the specified thread, such as Schedulers.io () to I/O thread, schedulers.Computation () to the calculation thread.
Below is a basic RXJAVA example:
import io.reactivex.Observable;
import io.reactivex.Observer;
import io.reactivex.disposables.Disposable;
public class RxJavaExample {
public static void main(String[] args) {
// Create observable and emit data event stream
Observable<Integer> observable = Observable.create(emitter -> {
emitter.onNext(1);
emitter.onNext(2);
emitter.onNext(3);
emitter.onComplete();
});
// Create Observer Subscribe to Observable
Observer<Integer> observer = new Observer<Integer>() {
@Override
public void onSubscribe(Disposable d) {
System.out.println("onSubscribe");
}
@Override
public void onNext(Integer integer) {
System.out.println("onNext: " + integer);
}
@Override
public void onError(Throwable e) {
System.out.println("onError: " + e.getMessage());
}
@Override
public void onComplete() {
System.out.println("onComplete");
}
};
// Subscribe to Observable and processed the event
observable.subscribe(observer);
}
}
In the above example, we created an Observable to launch an integer data event stream and create an Observer to subscribe and process this event stream.When Observable emits data, Observer prints the corresponding event information.
To sum up, the technical principles of RXJAVA include event flow processing of Observable and Observer, the event flow conversion and processing of the operator, and the asynchronous event processing of the thread -tunter.By using RXJAVA, we can handle asynchronous events more conveniently, simplify the complexity of concurrent programming, and improve the readability and maintenance of code.
