java - 如何根据嵌入的属性进行排序，并限制规范的结果数量？

我试图理解并找出以下用例的解决方案

这些是我的实体类

用户

@Entity
@Table(name = "USER")
public class User  {
  private UserID id;
  private Set<UserAddress> addresses = new HashSet<UserAddress>(0);
  @EmbeddedId
  @AttributeOverrides( {
        @AttributeOverride(name = "userId", column = @Column(name = "USER_ID", nullable = false, length = 32)),
        @AttributeOverride(name = "userType", column = @Column(name = "USER_TYPE", nullable = false, precision = 12, scale = 0)) })
  public User getId() {
     return this.id;
  }
  @OneToMany(fetch = FetchType.EAGER,  mappedBy = "user", cascade={CascadeType.ALL})
  @BatchSize(size=50)
  public Set<UserAddress> getAddresses() {
    return this.addresses;
  }
  ........
}

用户地址

@Entity
@Table(name = "USERADDRESS")
public class UserAddress  {
  private UserID id;
  Private User user;
  private String address;
  @EmbeddedId
  @AttributeOverrides( {
        @AttributeOverride(name = "userId", column = @Column(name = "USER_ID", nullable = false, length = 32)),
        @AttributeOverride(name = "userType", column = @Column(name = "USER_TYPE", nullable = false, precision = 12, scale = 0)) })
  public User getId() {
     return this.id;
  }
  @ManyToOne(fetch = FetchType.LAZY)
@JoinColumns( {
    @JoinColumn(name = "userId", referencedColumnName = "USER_ID", nullable = false, insertable=false, updatable=false),
    @JoinColumn(name = "userType", referencedColumnName = "USER_TYPE", nullable = false, insertable=false, updatable=false) })
  public User getUser() {
    return this.user;
  }
  ........
}

用户身份

@Embeddable
public class UserId implements Serializable {
   private String userNo;
   private Long UserType;
   .......
   .......
}

我已经为User，UserID和UserAddress创建了staticmetamodel类，并根据Specification创建了查询。

用户的元模型类

@StaticMetamodel(User.class)
public abstract class User_ {

  public static volatile SetAttribute<User, UserAddress> addresses;
  public static volatile SingularAttribute<User, UserID> id;
}

UserId的元模型

@StaticMetamodel(UserID.class)
public abstract class UserID_ {
   public static volatile SingularAttribute<UserID, String> userNo;
   public static volatile SingularAttribute<UserID, Long> UserType;
}

我正在尝试检索按UserType排序并根据userId搜索的最多10个User对象。该查询必须检索UserAddresses作为预先获取。

我的规范对象是

用户规格

public class UserSpecifications {
   public static Specification<User> userNoIs(String userNo) {
      return (root, query, cb) -> {
        root.fetch(User_.addresses);
        return cb.equal(root.get(User_.id).get(UserID_.userNo),userNo);
      };
   }
}

DAO功能：

 Sort sortInstructions = new Sort(Sort.Direction.DESC, "id.userNo");
 Specifications<User> specifications = Specifications.where(userNoIs(input.getUserNo()));
 List<User> userList = userRepository.findAll(specifications,sortInstructions);

我收到以下异常

java.lang.ClassCastException: org.hibernate.jpa.internal.metamodel.SingularAttributeImpl$Identifier cannot be cast to javax.persistence.metamodel.ManagedType
at org.hibernate.jpa.criteria.path.AbstractFromImpl.locateManagedType(AbstractFromImpl.java:139)
at org.hibernate.jpa.criteria.path.AbstractFromImpl.locateAttributeInternal(AbstractFromImpl.java:133)
at org.hibernate.jpa.criteria.path.AbstractPathImpl.locateAttribute(AbstractPathImpl.java:221)
at org.hibernate.jpa.criteria.path.AbstractPathImpl.get(AbstractPathImpl.java:194)
at org.springframework.data.jpa.repository.query.QueryUtils.toJpaOrder(QueryUtils.java:287)
at org.springframework.data.jpa.repository.query.QueryUtils.toOrders(QueryUtils.java:261)
at org.springframework.data.jpa.repository.support.SimpleJpaRepository.getQuery(SimpleJpaRepository.java:441)
at org.springframework.data.jpa.repository.support.SimpleJpaRepository.findAll(SimpleJpaRepository.java:294)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:322)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:307)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)

最佳答案

问题在于root.fetch(User_.userAddresses);-在您的User类中，您具有addresses而不是userAddresses，因此您可能为此错误地生成了元模型。

解决的另一件事应该是ListAttribute而不是SingularAttribute。

更新编辑：
尝试使用更新的版本，您描述的问题已在spring-data 1.5中解决