UserProjection.java

package com.example.wildmovies.entity;

import org.springframework.beans.factory.annotation.Value;

import java.util.List;
import java.util.stream.Collectors;

public interface UserProjection {

    static List<String> getMovieComments(List<Movie> movies) {
        return movies
                .stream()
                .map(movie -> movie
                        .getCommentList()
                        .stream()
                        .map(MovieComment::getContent)
                        .collect(Collectors.toList()))
                .reduce((result, commentList) -> {
                    result.addAll(commentList);
                    return result;
                }).orElseThrow();
    }

    String getEmail();

    @Value("#{T(com.example.wildmovies.entity.UserProjection).getMovieComments(target.getFavouriteMovies())}")
    List<String> getComments();
}