Hibernate+Struts2报错：无法解析根实体LoginHibernate求助

我是Stack Overflow新手，用Hibernate和Struts2开发登录验证器时遇到以下错误：

java.lang.IllegalArgumentException: org.hibernate.query.sqm.UnknownEntityException: Could not resolve root entity 'LoginHibernate'

我已经尝试修改hibernate.cfg.xml并检查Oracle数据库，但问题仍未解决，恳请帮忙排查原因。

LoginAction类 #

package action;

import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;
import dao.LoginDAOHibernate;
import pojo.LoginHibernate;

public class LoginAction extends ActionSupport {

    private String userName;
    private String password;

    public String execute() {
        String statusCode = "";
        HttpSession session = ServletActionContext.getRequest().getSession();
        System.out.println("execute() method called in LoginAction");

        // Create a LoginInfo object with the provided username and password
        LoginHibernate loginInfo = new LoginHibernate();
        loginInfo.setUserName(userName);
        loginInfo.setPassword(password);
        System.out.println("loginInfo called in LoginAction");

        boolean isUserValid = LoginDAOHibernate.isUserValid(loginInfo);

        // Set loggedInUser attribute in session if user is valid
        if (isUserValid) {
            session.setAttribute("loggedInUser", userName);
            statusCode = "success";
        } else {
            statusCode = "input";
        }
        return statusCode;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

}

LoginDAOHibernate类 #

package dao;

import org.hibernate.Session;
import org.hibernate.query.Query;

import dbutil.HibernateDBUtil;
import jakarta.persistence.NoResultException;
import jakarta.persistence.TypedQuery;
import pojo.LoginHibernate;

public class LoginDAOHibernate {
    
    public static boolean isUserValid(LoginHibernate userDetails) {
        boolean validStatus = false;
        Session session = null;

        try {
            session = HibernateDBUtil.getSessionFactory().openSession();

            // Create HQL query to check user credentials
            String hql = "FROM LoginHibernate WHERE userName = :userName AND password = :password";
            System.out.println("Called isUserValid() in LoginDaoHibernate");

            Query<LoginHibernate> query = session.createQuery(hql, LoginHibernate.class);
            System.out.println("Called user Query");
            query.setParameter("userName", userDetails.getUserName());
            query.setParameter("password", userDetails.getPassword());

            try {
                LoginHibernate user = query.getSingleResult();
                if (user != null) {
                    validStatus = true;
                    System.out.println("TEST LOGINDAO");
                }
            } catch (NoResultException e) {
                // No need to do anything here, as validStatus remains false
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // Close the Hibernate Session
            if (session != null) {
                session.close();
            }
        }

        return validStatus;
    }

}

HibernateDBUtil类 #

package dbutil;

import org.hibernate.SessionFactory;
import org.hibernate.boot.Metadata;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;

public class HibernateDBUtil {
    private static final SessionFactory sessionFactory = buildSessionFactory();

    private static SessionFactory buildSessionFactory() {
        try {
            StandardServiceRegistry standardRegistry = new StandardServiceRegistryBuilder()
                    .configure("hibernate.cfg.xml") // or "persistence.xml" if using JPA
                    .build();
            Metadata metadata = new MetadataSources(standardRegistry)
                    .addAnnotatedClass(pojo.LoginHibernate.class) // Ensure this matches your package and class name
                    .getMetadataBuilder()
                    .build();
            return metadata.getSessionFactoryBuilder().build();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }
}

LoginHibernate实体类 #

package pojo;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "login_info")
public class LoginHibernate {

    @Id
    @Column(name = "USER_NAME", nullable = false, unique = true)
    public String userName;

    @Column(name = "PASSWORD", nullable = false)
    public String password;

    // Default constructor (required by Hibernate)
    public LoginHibernate() {
    }

    // Constructor with fields
    public LoginHibernate(String userName, String password) {
        this.userName = userName;
        this.password = password;
    }

    // Getters and setters
    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

排查方向： #

• 统一JPA包导入：代码里同时出现了javax.persistence.*（实体类）和jakarta.persistence.*（DAO类），Hibernate 6+使用Jakarta EE规范，Hibernate 5及以下使用Java EE的javax包，混用会导致实体无法被识别。要么全换成jakarta.persistence.*（对应Hibernate 6+），要么全用javax.persistence.*（对应Hibernate 5.x）。

• 确认实体注册是否生效：

  1. 检查HibernateDBUtil中addAnnotatedClass(pojo.LoginHibernate.class)的包路径和类名是否完全正确，有没有拼写错误。
  2. 或者直接在hibernate.cfg.xml中添加实体映射配置：<mapping class="pojo.LoginHibernate"/>，两种方式选其一即可。
  3. 查看控制台输出的buildSessionFactory()异常信息，确认SessionFactory是否成功初始化，如果初始化失败返回null，后续的Session操作必然报错。

• 检查HQL语句的实体名：HQL中的实体名必须和实体类的类名完全一致（大小写敏感），如果实体类用了@Entity(name="自定义名称")，那HQL里要使用这个自定义名称；当前没有设置name属性，用类名LoginHibernate是正确的，确保拼写无误。

• 验证依赖版本兼容性：Struts2和Hibernate的版本要匹配，比如Struts2 6.x依赖Jakarta EE，必须搭配Hibernate 6.x；如果用Struts2 5.x，可以搭配Hibernate 5.x，避免版本不兼容导致的实体识别问题。

• 核对数据库表映射：Oracle数据库默认表名和列名是大写的，确认@Table(name = "login_info")对应的数据库表实际是LOGIN_INFO，如果不一致，修改注解为@Table(name = "LOGIN_INFO")；列名同理，确保@Column(name = "USER_NAME")和数据库列名一致。

内容的提问来源于stack exchange，提问作者Kenneth Igot