RxJava: How to convert List of objects to List of another objects

Question

I have the List of SourceObjects and I need to convert it to the List of ResultObjects.

I can fetch one object to another using method of ResultObject:

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Answer 1

The Observable.from() factory method allows you to convert a collection of objects into an Observable stream. Once you have a stream you can use the map operator to transform each emitted item. Finally, you will have to subscribe to the resulting Observable in order to use the transformed items:

// Assuming List srcObjects
Observable resultsObjectObservable = Observable.from(srcObjects).map(new Func1() {
    @Override
    public ResultsObject call(SourceObject srcObj) {
        return new ResultsObject().convertFromSource(srcObj);
    }
});

resultsObjectObservable.subscribe(new Action1() { // at this point is where the transformation will start
    @Override
    public void call(ResultsObject resultsObject) { // this method will be called after each item has been transformed
        // use each transformed item
    }
});

The abbreviated version if you use lambdas would look like this:

Observable.from(srcObjects)
  .map(srcObj -> new ResultsObject().convertFromSource(srcObj))
  .subscribe(resultsObject -> ...);