carSalesman

package carSalesman;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class Main {
    static List<Car> carList = new ArrayList<>();
    static List<Engine> engineList = new ArrayList<>();

    public static void main(String[] args) throws IOException {
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        int engineCount = Integer.parseInt(bf.readLine());
        for(int i = 0;i <engineCount ;i++){
            String [] engineInput = bf.readLine().split("\\s+");
            addEngine(engineInput);
        }
        int carCount = Integer.parseInt(bf.readLine());
        for(int i = 0; i< carCount;i++){
            String [] carInput = bf.readLine().split("\\s+");
            addCar(carInput);
        }
        carList.stream().forEach(System.out::println);
    }

    private static void addCar(String[] carInput) {

        String carModel = carInput[0];
        String engineModel = carInput[1];
        String carWeight = null;
        String  carColor = null;

        if(carInput.length>2){
            carWeight = tryParse(carInput[2]);
            carColor = carInput.length>3 ? carInput[3] : carWeight==null ? carInput[2] : null;
        }
        for(Engine engine : engineList){
            if(engine.getEngineModel().equals(engineModel)){
                Car currentCar = new Car(carModel,engine,carWeight,carColor);
                carList.add(currentCar);
                break;
            }
        }
    }

    public static void addEngine(String[] engineInput){
        String engineModel = engineInput[0];
        Integer enginePower = Integer.parseInt(engineInput[1]);
        String engineDisplacement = null;
        String engineEfficiency = null;
        if(engineInput.length>2){
            engineDisplacement = tryParse(engineInput[2]);
            engineEfficiency = engineInput.length>3 ? engineInput[3] : engineDisplacement==null ? engineInput[2] : null;
        }
        Engine currentEngine = new Engine(engineModel,enginePower,engineDisplacement,engineEfficiency);
        engineList.add(currentEngine);
    }
    public static String tryParse(Object obj) {
        String retVal;
        Integer tryNum;
        try {
            tryNum = Integer.parseInt((String) obj);
            retVal = tryNum.toString();
        } catch (NumberFormatException nfe) {
            retVal = null;
        }
        return retVal;
    }
}
 class Engine {
    String engineModel;
    Integer enginePower;
    String engineDisplacement;
    String efficiency;

    Engine(String model, Integer power, String displacement, String efficiency) {
        this.setEngineModel(model);
        this.setEnginePower(power);
        this.setEngineDisplacement(displacement);
        this.setEfficiency(efficiency);
    }

    public String getEngineModel() {
        return this.engineModel;
    }

    private void setEngineModel(String engineModel) {
        this.engineModel = engineModel;
    }

    public int getEnginePower() {
        return this.enginePower;
    }

    private void setEnginePower(Integer enginePower) {
        this.enginePower = enginePower;
    }

    public String getEngineDisplacement() {
        return this.engineDisplacement;
    }

    private void setEngineDisplacement(String engineDisplacement) {
        if (engineDisplacement == null) {
            this.engineDisplacement = "n/a";
            return;
        }
        this.engineDisplacement = engineDisplacement;
    }

    public String getEfficiency() {
        return this.efficiency;
    }

    private void setEfficiency(String efficiency) {
        if (efficiency == null) {
            this.efficiency = "n/a";
            return;
        }
        this.efficiency = efficiency;
    }
}
 class Car {
    private String carModel;
    private Engine carEngine;
    private String carWeight;
    private String carColor;

    public Car(String carModel, Engine carEngine, String carWeight, String carColor) {
        this.setCarModel(carModel);
        this.setCarEngine(carEngine);
        this.setCarWeight(carWeight);
        this.setCarColor(carColor);
    }

    public String getCarModel() {
        return carModel;
    }

    private void setCarModel(String carModel) {
        this.carModel = carModel;
    }

    public Engine getCarEngine() {
        return carEngine;
    }

    private void setCarEngine(Engine carEngine) {
        this.carEngine = carEngine;
    }

    public String getCarWeight() {
        return carWeight;
    }

    public void setCarWeight(String carWeight) {
        if (carWeight == null) {
            this.carWeight = "n/a";
            return;
        }
        this.carWeight = carWeight;
    }

    public String getCarColor() {
        return carColor;
    }

    private void setCarColor(String carColor) {
        if (carColor == null) {
            this.carColor = "n/a";
            return;
        }
        this.carColor = carColor;
    }

    @Override
    public String toString() {
        StringBuilder carBuilder = new StringBuilder();
        carBuilder.append(String.format("%s:\n",this.getCarModel()));
        carBuilder.append(String.format("  %s:\n",this.getCarEngine().getEngineModel()));
        carBuilder.append(String.format("\tPower: %d\n",this.getCarEngine().getEnginePower()));
        carBuilder.append(String.format("\tDisplacement: %s\n",this.getCarEngine().getEngineDisplacement()));
        carBuilder.append(String.format("\tEfficiency: %s\n",this.getCarEngine().getEfficiency()));
        carBuilder.append(String.format("  Weight: %s\n",this.getCarWeight()));
        carBuilder.append(String.format("  Color: %s",this.getCarColor()));

        String output = carBuilder.toString();
        return output;
    }
}