io.mstream.trader.simulation.handlers.api.PayloadExtractor Maven / Gradle / Ivy

package io.mstream.trader.simulation.handlers.api;


import com.fasterxml.jackson.databind.ObjectMapper;
import io.mstream.trader.commons.utils.exception.ParsingException;
import ratpack.http.TypedData;
import rx.Observable;
import rx.functions.Func1;

import java.io.IOException;
import java.lang.reflect.ParameterizedType;


public class PayloadExtractor
        implements Func1> {
    
    private final Class type;
    
    private final ObjectMapper objectMapper;
    
    protected PayloadExtractor(ObjectMapper objectMapper) {
        
        type =
                (Class) ((ParameterizedType) getClass()
                        .getGenericSuperclass())
                        .getActualTypeArguments()[0];
        
        this.objectMapper = objectMapper;
    }
    
    @Override
    public Observable call(TypedData body) {
        
        try {
            T payload =
                    objectMapper
                            .readValue(
                                    body.getBytes(),
                                    type
                            );
            return Observable.just(payload);
        } catch (IOException e) {
            return Observable.error(
                    ParsingException.get()
            );
        }
    }
}