package com.example.firstproject.api;import com.example.firstproject.dto.ArticleForm;import com.example.firstproject.entity.Article;import com.example.firstproject.repository.ArticleRepository;// import lombok.AllArgsConstructor;// import lombok.NoArgsConstructor;// import lombok.RequiredArgsConstructor;import org.springframework.web.bind.annotation.*;import java.util.List;@RestControllerpublic class ArticleApiController {private ArticleRepository articleRepository;private ArticleForm dto;@GetMapping("/api/articles")public List<Article> index() {return articleRepository.findAll();}@GetMapping("/api/articles/{id}")public Article index(@PathVariable Long id) {return articleRepository.findById(id).orElse(null);}@PostMapping("/api/articles")public Article create(@RequestBody ArticleForm dto) {Article article = dto.toEntity();return articleRepository.save(article);}} PostMapping하고 있는데, Talend API Tester에서 아래와 같이 실행시키면 안돼여에러메시지는 아래와 같습니다Cannot invoke "com.example.firstproject.repository.ArticleRepository.save(Object)" because "this.articleRepository" is null라고 떠여... 그래서 ArticleRepository를 확인해보면ArticleRepository는package com.example.firstproject.repository;import com.example.firstproject.entity.Article;import org.springframework.data.repository.CrudRepository;import java.util.ArrayList;public interface ArticleRepository extends CrudRepository<Article, Long> {@OverrideArrayList<Article> findAll();}으로 썜이랑 똑같이 작성했어요 쌤.... 제가 뭘 잘못 했나여............뭘 고치면 되나여......... 살려주십셔.,,,,,,,,,,,,,.