Java Hibernate 5未映射MySQL表+

我正在尝试使用名为world的MySQL内置数据库学习Hibernate。它有三个表格，分别是城市、乡村和乡村语言。我要做的是执行SQL语句SELECT*FROM world.city；。当我运行我的项目时，我得到了一个错误

org.hibernate.hql.internal.ast.QuerySyntaxException: City is not mapped [from City]

我正在使用IntelliJ IDEA和Hibernate 5.2.8

我创建了如下映射xml文件：

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="pl.hibernatePackage">

<class name="City" table="city">

    <id name="id" column="ID" type="int">
        <generator class="native"/>
    </id>
    <property name="name" column="Name" type="string"/>
    <property name="countryCode" column="CountryCode" type="string"/>
    <property name="district" column="District" type="string"/>
    <property name="population" column="Population" type="int"/>

</class>

</hibernate-mapping>

我正在HibernateUtil.java中创建会话

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;

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

private static SessionFactory buildSessionFactory() {
    try {
        Configuration configuration = new Configuration();
        configuration.configure();

        StandardServiceRegistry standardRegistry = new StandardServiceRegistryBuilder()
                .configure()
                .build();

        return configuration.buildSessionFactory(standardRegistry);
    }
    catch(Exception e) {
        throw new ExceptionInInitializerError(e);
    }
}

public static Session getSession()
{
    return sessionFactory.openSession();
}

public static void close()
{
    sessionFactory.close();
}
}

配置文件

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration SYSTEM
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
<session-factory>
    <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/world</property>
    <property name="hibernate.connection.username">test</property>
    <property name="hibernate.connection.password">1234</property>
    <property name="connection.pool_size">1</property>
    <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
    <property name="current_session_context_class">thread</property>
    <property name="show_sql">false</property>
    <property name="hbm2ddl.auto">update</property>

    <!-- List of XML mapping files -->
    <mapping resource="pl/hibernatePackage/City.hbm.xml"/>

</session-factory>
</hibernate-configuration>

主要

public class Main
{
public static void main(String[] args)
{
    Session session = HibernateUtil.getSessionFactory().getCurrentSession();
    session.beginTransaction();

    List<City> cities = session.createQuery("from City").list();

    for(City c : cities) {
        System.out.println(c.getId() + "\t" + c.getName() + "\t" + c.getCountryCode() + "\t" + c.getDistrict() +
                "\t" + c.getPopulation());
    }

    session.getTransaction().commit();

    HibernateUtil.getSessionFactory().close();
}
}

编辑完整错误列表

编辑2 javac结果

---

我已经做了一些测试，并通过使用完全限定的类名使其工作：

session.createQuery("from pl.hibernatePackage.City")

现在，这只是一个不涉及配置的解决方法

深入挖掘之后，我发现自hibernate版本5.x以来，构建sessionFactory的策略有所不同

我通过实现sessionFactory实现了您的示例，如下所示：

StandardServiceRegistry standardRegistry = new StandardServiceRegistryBuilder()
    .configure()
    .build();

Metadata metadata = new MetadataSources( standardRegistry )
   .getMetadataBuilder()
   .build();

return configuration.buildSessionFactory(serviceRegistry);

---

这里用例子解释了这一点：第2.4点

多亏了Maciej的回答和其他人的帮助，我通过修改代码和稍微清理代码使我的示例得以运行。我还发现用xml文件映射数据库已经过时了，所以我正确修改了CityEntity类。最终代码：

Main.java

import org.hibernate.Session;
import java.util.List;

public class Main
{
public static void main(String[] args)
{
    Session session = HibernateUtil.getSession();
    session.beginTransaction();

    List<CityEntity> cities = session.createQuery("from CityEntity").list();

    for(CityEntity c : cities)
    {
        System.out.println(c.getId() + "\t" + c.getName() + "\t" + c.getCountryCode() + "\t" + c.getDistrict() +
                "\t" + c.getPopulation());
    }

    session.getTransaction().commit();

    HibernateUtil.close();
}
}

CityEntity.java

import javax.persistence.*;

@Entity
@Table(name = "city", schema = "world")
public class CityEntity
{
private int id;
private String name;
private String countryCode;
private String district;
private int population;

@Basic
@Column(name = "CountryCode")
public String getCountryCode() {
    return countryCode;
}

public void setCountryCode(String countryCode) {
    this.countryCode = countryCode;
}

@Id
@Column(name = "ID")
public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

@Basic
@Column(name = "Name")
public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

@Basic
@Column(name = "District")
public String getDistrict() {
    return district;
}

public void setDistrict(String district) {
    this.district = district;
}

@Basic
@Column(name = "Population")
public int getPopulation() {
    return population;
}

public void setPopulation(int population) {
    this.population = population;
}
}

---

您把配置文件放在哪里了？它在src folderI中，我的意思是不在任何包或其他东西中，只在src文件夹中，就像它的顶部一样。。当您在不使用Intellij的情况下运行该程序时。。它能用吗？我不知道，因为除了IntelliJ我没有任何IDE

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration SYSTEM
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
<session-factory>
    <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/world</property>
    <property name="hibernate.connection.username">root</property>
    <property name="hibernate.connection.password">1234</property>
    <property name="connection.pool_size">1</property>
    <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
    <property name="show_sql">true</property>
    <property name="hbm2ddl.auto">update</property>

    <!-- List of mapped classes -->
    <mapping class="CityEntity"/>

</session-factory>
</hibernate-configuration>

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;

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

private static SessionFactory buildSessionFactory() {
    try {
        Configuration configuration = new Configuration();
        configuration.configure();

        StandardServiceRegistry standardRegistry = new StandardServiceRegistryBuilder()
                .configure()
                .build();

        return configuration.buildSessionFactory(standardRegistry);
    }
    catch(Exception e) {
        throw new ExceptionInInitializerError(e);
    }
}

public static Session getSession()
{
    return sessionFactory.openSession();
}

public static void close()
{
    sessionFactory.close();
}
}

import javax.persistence.*;

@Entity
@Table(name = "city", schema = "world")
public class CityEntity
{
private int id;
private String name;
private String countryCode;
private String district;
private int population;

@Basic
@Column(name = "CountryCode")
public String getCountryCode() {
    return countryCode;
}

public void setCountryCode(String countryCode) {
    this.countryCode = countryCode;
}

@Id
@Column(name = "ID")
public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

@Basic
@Column(name = "Name")
public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

@Basic
@Column(name = "District")
public String getDistrict() {
    return district;
}

public void setDistrict(String district) {
    this.district = district;
}

@Basic
@Column(name = "Population")
public int getPopulation() {
    return population;
}

public void setPopulation(int population) {
    this.population = population;
}
}