How can i use exceptions in springboot-CodePudding

i am new in spring boot, i following the tuorial from Pluralsight.

i got problem by using exceptions

here is my service interface

package com.stev.pillecons.pilleCons.services;

import com.stev.pillecons.pilleCons.models.LePille;

import java.util.List;

public interface PilleService {
    List<LePille> listPilles();
    LePille findPille(Integer id);
}

here is how i implements the services

package com.stev.pillecons.pilleCons.services;

import com.stev.pillecons.pilleCons.exceptions.PilleException;
import com.stev.pillecons.pilleCons.models.LePille;
import com.stev.pillecons.pilleCons.repositories.LePilleRepo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Optional;

@Service
public class PilleServiceImpl implements PilleService{

    @Autowired
    private LePilleRepo pilleRepo;

    @Override
    public List<LePille> listPilles() {
        return (List<LePille>) pilleRepo.findAll();
    }

    @Override
    public LePille findPille(Integer id) {
        Optional<LePille> optionalLePille = pilleRepo.findById(id);

        if (optionalLePille.isPresent())
            return optionalLePille.get();
        else
            return new PilleException("pille not found");

    }
}

i got red under line to this line : return new PilleException("pille not found");

here is my exception

package com.stev.pillecons.pilleCons.exceptions;

public class PilleException extends RuntimeException {

    public PilleException (String ex) {super(ex);}
}

EDIT

i use this code

 @Override
    public LePille findPille(Integer id) {
        return pilleRepo.findById(id).orElseThrow(()-> new PilleException("pille not found"));
    }

it works, why my code doesn't work ?

CodePudding user response：

An exception is not returned it is thrown.

throw new PilleException("pille not found");

CodePudding user response：

Simon is correct and one of the best practice to handle exceptions is using @ControllerAdvice and handle all @ExceptionHandlers from single point.