dto/ArticleForm.java

public class ArticleForm {
(중략)
    public ArticleForm(String title, String content) {
        this.title = title;
        this.content = content;
    }
   // 데이터를 잘 받았는지 확인할 toString() 메서드 추가

    @Override
    public String toString() {
        return "ArticleForm{" +
                "title='" + title + '\'' +
                ", content='" + content + '\'' +
                '}';
    }

}