java - java.lang.IllegalArgumentException 参数值 [com..schoolmanagement.model.exam.QuestionPaper@7d78f8f] 与预期类型不匹配

Question

我宣布了两个班级，QuestionPaper

@AllArgsConstructor
@NoArgsConstructor
@Getter
@Setter
@Entity
@Component
public class QuestionPaper {
    @Id
    private String id = UUID.randomUUID().toString();
    @ManyToOne
    @JoinColumn(name = "courseId")
    private Course course;
    private String paperTitle;
    private String paperDsc;
    private String duration;
    private Date dateCreated = new Date();
    private Date lastUpdated;
    private String paperCode;
    private String createdById;

}

和Question

@AllArgsConstructor
@Getter
@Setter
@NoArgsConstructor
@Entity
public class Question {
    @Id
    private String id = UUID.randomUUID().toString();
    @ManyToOne
    @JoinColumn(name = "courseId")
    private Course course;
    private int questionNo;
    private String question;
    private String answerOne;
    private String answerTwo;
    private String answerThree;
    private String answerFour;
    private String correctAnswer;
    @ManyToOne
    @JoinColumn(name = "questionPaperId")
    private QuestionPaper questionPaper;

}

我的数据库是 postgres 我创建了一份试卷

现在，每当我尝试通过 QuestionPaper 获取问题列表时

List<Question> questionList = questionRepository.findAllByQuestionPaperOrderByQuestionNoAsc(questionPaperService.getQuestionPaperById(questionPaperId).get());

我得到以下例外

java.lang.IllegalArgumentException 参数值 [com.chaitanya.schoolmanagement.model.exam.QuestionPaper@7d78f8f] 与预期类型不匹配 [com.chaitanya.schoolmanagement.model.exam.QuestionPaper (n/a)];

标签： javapostgresqlspring-bootjpa