java.lang.ClassCastException：[Ljava.lang.Object;不能转换为entity.UserEntity [英] java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to entity.UserEntity

问题描述

我想在休眠中查询两个表。
填充用户实体中的3个表（用户 - 角色 - 配置文件）。
query with hql：

  query =从UserEntity中选择ue，ue.roleEntity.roleIe ue，RoleEntity re fetch所有属性，其中ue.roleEntity.roleId = re.roleId和ue.username ='reza'和ue.password ='123456'; 
  

并运行查询：

  try {
 sessionFactory = HibernateUtil.getSessionFactory（）; 
 session = sessionFactory.getCurrentSession（）; 
 transaction = session.beginTransaction（）; 
 userEntityList =（List< UserEntity>）session.createQuery（query）.list（）; 
 transaction.commit（）; 
 catch（HibernateException e）{
 try {
抛出新的DaoException（e中的胎儿异常）; 
} catch（DaoException e1）{
 e1.printStackTrace（）; 
 
 
 
 
 
 
 $ p $ useType class：
这个类是geteer和seter：
 
 
  public class UserEntity {
 private int userId; 
私人长期personalCode; 
私人字符串用户名; 
私人字符串密码; 
私人短期活跃; 
私人字符串问题; 
 private String被动; 
私人档案实体档案实体; 
 private RoleEntity roleEntity; 
  
 
 
  hibernate map for userEntity.hbm.xml  
 
 
 <？xml version =1.0encoding =utf-8？> 
<！DOCTYPE hibernate-mapping PUBLIC 
 -  // Hibernate / Hibernate映射DTD 3.0 // EN
http://hibernate.sourceforge.net/hibernate-mapping-3.0 .dtd> 
 
< hibernate-mapping package =entity> 
< class name =UserEntitytable =TABLE_USER> 
< id name =userIdtype =java.lang.Integercolumn =USER_ID> 
< generator class =increment/> 
< / id> 
 
< property name =personalCodetype =java.lang.Longcolumn =PERSONALCODE> 
 
< / property> 
 
< property name =usernametype =java.lang.Stringcolumn =USERNAME> 
 
< / property> 
 
< property name =passwordtype =java.lang.Stringcolumn =PASSWORD> 
 
< / property> 
 
  
< / property> 
 
< property name =questiontype =java.lang.Stringcolumn =QUCTION> 
 
< / property> 
 
  
< / property> 
 
 
<多对一名称=roleEntityclass =entity.RoleEntitycolumn =ROLE_IDcascade =nonefetch =select/> 
  
< / class> 
< / hibernate-mapping> 
  
和类hibernateutil用于创建操作： 
 
 
  import org.hibernate.SessionFactory; 
 import org.hibernate.boot.registry.StandardServiceRegistryBuilder; 
导入org.hibernate.cfg.Configuration; 
 
 public class HibernateUtil {
 private static SessionFactory sessionFactory; 
 
 static {
 try {
 Configuration configuration = new Configuration（）。configure（）; 
 StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder（）。applySettings（configuration.getProperties（））; 
 sessionFactory = configuration.buildSessionFactory（builder.build（））; 
} catch（Throwable th）{
 
 System.err.println（Enitial SessionFactory creation failed+ th）; 
 
抛出新的ExceptionInInitializerError（th）; 
 
 
 
 
 $ ** 
 * @return 
 * / 
 public static SessionFactory getSessionFactory （）{
 
 return sessionFactory; 
 
 
 $ b  
 
 
解决方案
因为您使用的是多选投影，所以您实际上正在获取一组对象，因此您需要将查询结果处理逻辑更改为： 
 
 
 列表与LT;对象[]> tuples =（List< Object []>）session.createQuery（query）.list（）; 
 
 for（Object [] tuple：tuples）{
 UserEntity ue = tuple [0]; 
数字roleId =元组[1]; 
} 
  
 
i want query two table  in hibernate .
featch 3 table (User - Role - Profile ) in user Entity .
query with hql :
query= "select ue, ue.roleEntity.roleId from UserEntity ue ,RoleEntity re  fetch all properties where ue.roleEntity.roleId=re.roleId and ue.username ='reza' and ue.password='123456'";
and run query :
  try {
        sessionFactory = HibernateUtil.getSessionFactory();
        session = sessionFactory.getCurrentSession();
        transaction = session.beginTransaction();
        userEntityList = (List<UserEntity>) session.createQuery(query).list();
        transaction.commit();
    } catch (HibernateException e) {
        try {
            throw new DaoException("Fetal exception in", e);
        } catch (DaoException e1) {
            e1.printStackTrace();
        }
    }
userentity class :
this class is geteer and seter :
public class UserEntity {
private int userId;
private long personalCode;
private String username;
private String password;
private short active;
private String question;
private String passive;
private ProfileEntity  profileEntity;
private RoleEntity roleEntity;
hibernate maping for userEntity.hbm.xml
        <?xml version="1.0" encoding="utf-8" ?>
    <!DOCTYPE hibernate-mapping PUBLIC
            "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
            "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

    <hibernate-mapping package="entity">
        <class name="UserEntity" table="TABLE_USER">
            <id name="userId" type="java.lang.Integer" column="USER_ID">
                <generator class="increment" />
            </id>

            <property name="personalCode" type="java.lang.Long" column="PERSONALCODE">

            </property>

            <property name="username" type="java.lang.String" column="USERNAME">

            </property>

            <property name="password" type="java.lang.String" column="PASSWORD">

            </property>

            <property name="active" type="java.lang.Short" column="ACTIVE">

            </property>

            <property name="question" type="java.lang.String" column="QUCTION">

            </property>

            <property name="passive" type="java.lang.String" column="PASSIVE">

            </property>


            <many-to-one name="roleEntity" class="entity.RoleEntity" column="ROLE_ID" cascade="none" fetch="select" />
            <many-to-one name="profileEntity" class="ProfileEntity" cascade="delete" column="profile_id"/>

    </class>
</hibernate-mapping>
and class hibernateutil  for create sesstion :
  import org.hibernate.SessionFactory;
    import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
    import org.hibernate.cfg.Configuration;

    public class HibernateUtil {
        private static SessionFactory sessionFactory;

        static {
            try {
                Configuration configuration = new Configuration().configure();
                StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties());
                sessionFactory = configuration.buildSessionFactory(builder.build());
            } catch (Throwable th) {

                System.err.println("Enitial SessionFactory creation failed" + th);

                throw new ExceptionInInitializerError(th);

            }

        }

        /**
         * @return
         */
        public static SessionFactory getSessionFactory() {

            return sessionFactory;

        }
    }

解决方案
Because you are using a multi-selection projection, you are actually fetching an array of objects, so you need to change the query result processing logic to:
List<Object[]> tuples = (List<Object[]>) session.createQuery(query).list();

for(Object[] tuple : tuples) {
    UserEntity ue = tuple[0];
    Number roleId = tuple[1];
}


                        
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