org.hibernate.UnknownEntityTypeException：无法定位实体描述符：com.example.test.Person

Question

我不断遇到不同类型配置的相同问题：基于 xml 和 java。 这是一个简单的代码示例。 人.java:

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

@Entity
@Table(name = "Person")
public class Person {

    @Id
    @Column(name = "id")
    private int id;

    @Column(name = "name")
    private String name;

    @Column(name = "age")
    private int age;

    public Person() {}

    public Person(int id, String name, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

TestApplication.java:

package com.example.test;

import org.hibernate.Session;
import org.hibernate.SessionFactory;

import org.hibernate.cfg.Configuration;


public class TestApplication {

    public static void main(String[] args) {
        Configuration configuration = new Configuration().configure().addAnnotatedClass(Person.class);


        SessionFactory sessionFactory = configuration.buildSessionFactory();

        Session session = sessionFactory.getCurrentSession();

        try {
            session.beginTransaction();

            Person person = session.get(Person.class, 1);
            System.out.println(person.getName());
            System.out.println(person.getAge());

            session.getTransaction().commit();

        } finally {
            sessionFactory.close();
        }
    }

}

pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.0.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>test</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>test</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.13.1</version>
                <scope>test</scope>
            </dependency>

            <!-- https://mvnrepository.com/artifact/org.postgresql/postgresql -->
            <dependency>
                <groupId>org.postgresql</groupId>
                <artifactId>postgresql</artifactId>
                <version>42.2.27</version>
            </dependency>

            <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-core -->
            <dependency>
                <groupId>org.hibernate</groupId>
                <artifactId>hibernate-core</artifactId>
                <version>5.6.4.Final</version>
            </dependency>
        </dependencies>


    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

我还尝试了 hibernate.properties 和 hibernate.cfg.xml（当前代码使用的是最后一个）。 以下是这些文件： 休眠.properties

hibernate.driver_class=org.postgresql.Driver
hibernate.connection.url=jdbc:postgresql://localhost:5432/test
hibernate.connection.username=postgres
hibernate.connection.password=postgres


hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect
hibernate.show_sql=true
hibernate.current_session_context_class=thread

hibernate.cfg.xml

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">



<hibernate-configuration>
    <session-factory>
        <property name="connection.url">jdbc:postgresql://localhost:5432/postgres</property>
        <property name="connection.driver_class">org.postgresql.Driver</property>
        <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
        <property name="connection.username">postgres</property>
        <property name="connection.password">postgres</property>
        <property name="hibernate.current_session_context_class">thread</property>
        <property name="hibernate.show_sql">true</property>

        <mapping class="com.example.test.Person"/>

        <!-- DB schema will be updated if needed -->
        <!-- <property name="hibernate.hbm2ddl.auto">update</property> -->
    </session-factory>
</hibernate-configuration>

请帮帮我……我快绝望了。不知何故，我的实体一直没有被 Hibernate 注意到。我也尝试过使用 persistence.xml 但没有成功..

Answer 1

替换

<!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-core -->
            <dependency>
                <groupId>org.hibernate</groupId>
                <artifactId>hibernate-core</artifactId>
                <version>5.6.4.Final</version>
            </dependency>

与

<!-- https://mvnrepository.com/artifact/org.hibernate.orm/hibernate-core -->
<dependency>
    <groupId>org.hibernate.orm</groupId>
    <artifactId>hibernate-core</artifactId>
    <version>6.1.7.Final</version>
</dependency>

这样做的原因是 Spring 6 淘汰了所有带有

javax

的包并移动到名为

jakarta

的包 Hibernate 5 使用 javax，Hibernate 6 使用 jakarta。

替换这些依赖项后，再次拉取它们（通过使用您的 IDE 或

mvn clean install

命令），并确保替换您可能留在项目中的 ALL javax 导入

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

到

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