无法在具有@IdClass的实体中转换请求元素

只是您的代码不符合JPA。问题的原因是您将其

Member

1. 基元 ：布尔值，字节，字符，整数，长，短
2. java.lang ：布尔值，字节，字符，整数，长，短，字符串，枚举，StringBuffer
3. java.math ：BigInteger java.sql：Date，Time，Timestamp
4. java.util ：日期，货币，语言环境，时区，UUID
5. **java.net** ：URI，URL
6. javax.jdo.spi ：PersistenceCapable
   
   

这应该工作：

@Embeddablepublic class MemberAttributePk implements Serializable {    @Column(name = "member_id")    protected Long memberId;    @Column(name = "name")    protected String name;    public MemberAttributePk() {}    // get & set}@Entitypublic class MemberAttribute {    @EmbeddedId    protected MemberAttributePk memberAttributePk;    @ManyToOne     @JoinColumn(name="member_id")    protected Member member;    private String value;    public MemberAttribute() {}    // get & set}

还是一样

@ClassId

public class MemberAttributePk implements Serializable {    protected Long memberId;    protected String name;    public MemberAttributePk() {}    // get & set}@Entity@IdClass(MemberAttributePk.class)public class MemberAttribute {    @Id    @Column(name = "member_id")    protected Long memberId;    @Id    @Column(name = "name")    protected String name;    @ManyToOne     @JoinColumn(name="member_id")    protected Member member;    private String value;    public MemberAttribute() {}    // get & set}