问题：-Spring Hibernate项目中的未知实体

Question

我是Spring和Hibernate的新手，它试图在其中实现某些CRUD应用程序。 主要类别：

import java.util.Date;

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

import com.models.Employee1;
import com.utils.HibernateUtils;


public class HibernateAnnoationMain {

public static void main(String[] args) {
    Employee1 emp = new Employee1();
    emp.setName("David");
    emp.setRole("Developer");
    emp.setInsertTime(new Date());

    //Get Session
    SessionFactory sessionFactory = HibernateUtils.getSessionAnnotationFactory();
    Session session = sessionFactory.getCurrentSession();
    //start transaction
    session.beginTransaction();
    //Save the Model object
    session.save(emp);
    //Commit transaction
    session.getTransaction().commit();
    System.out.println("Employee ID="+emp.getId());

    //terminate session factory, otherwise program won't end
    sessionFactory.close();
}

}

休眠实用程序类

import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;

public class HibernateUtils {
private static SessionFactory sessionAnnotationFactory;

public static SessionFactory getSessionAnnotationFactory() {
    if (sessionAnnotationFactory == null)
        sessionAnnotationFactory = buildSessionAnnotationFactory();
    return sessionAnnotationFactory;
}

public static void setSessionAnnotationFactory(SessionFactory sessionAnnotationFactory) {
    HibernateUtils.sessionAnnotationFactory = sessionAnnotationFactory;
}

private static SessionFactory buildSessionAnnotationFactory() {
    try {
        // Create the SessionFactory from hibernate.cfg.xml
        Configuration configuration = new Configuration();
        configuration.configure("hibernate-annotation.cfg.xml");
        System.out.println("Hibernate Annotation Configuration loaded");

        ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
                .applySettings(configuration.getProperties()).build();
        System.out.println("Hibernate Annotation serviceRegistry created");

        SessionFactory sessionFactory = configuration.buildSessionFactory(serviceRegistry);

        return sessionFactory;
    } catch (Throwable ex) {
        // Make sure you log the exception, as it might be swallowed
        System.err.println("Initial SessionFactory creation failed." + ex);
        throw new ExceptionInInitializerError(ex);
    }
}

}

获取未知实体错误

Exception in thread "main" org.hibernate.MappingException: Unknown entity: com.models.Employee1
at org.hibernate.metamodel.internal.MetamodelImpl.entityPersister(MetamodelImpl.java:704)
at org.hibernate.internal.SessionImpl.getEntityPersister(SessionImpl.java:1732)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:118)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192)
at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177)
at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)
at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:713)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:705)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:700)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.hibernate.context.internal.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:350)
at com.sun.proxy.$Proxy26.save(Unknown Source)
at com.main.HibernateAnnoationMain.main(HibernateAnnoationMain.java:26)

在Internet上浏览一番之后，我试图将spring和hibernate版本的竞争力与MySql jars匹配。

休眠xml文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <!-- Database connection properties - Driver, URL, user, password -->
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://127.0.0.1:3306/HibernateProject?useSSL=false</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">root</property>
        <!-- JDBC connection pool settings ... using built-in test pool -->
        <property name="connection.pool_size">10</property>
        <!-- Select our SQL dialect -->
        <property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>
        <!-- Echo the SQL to stdout -->
        <property name="show_sql">true</property>
        <!-- Set the current session context -->
        <property name="current_session_context_class">thread</property>
        <!-- Drop and re-create the database schema on startup -->
        <property name="hbm2ddl.auto">update</property>
        <mapping class="com.models.Employee1" />

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

模型类别：Employee1

package com.models;

import java.util.Date;

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

@Entity
@Table
public class Employee1 {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="ID", nullable=false, unique=true, length=11)
    private int id;

    @Column(name="NAME", length=20, nullable=true)
    private String name;

    @Column(name="ROLE", length=20, nullable=true)
    private String role;

    @Column(name="insert_time", nullable=true)
    private Date insertTime;

    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 String getRole() {
        return role;
    }
    public void setRole(String role) {
        this.role = role;
    }
    public Date getInsertTime() {
        return insertTime;
    }
    public void setInsertTime(Date insertTime) {
        this.insertTime = insertTime;
    }
}

POM.xml

<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>Devendra_Ghag</groupId>
<artifactId>HibernateProjectPratice</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-agroal</artifactId>
        <version>5.4.2.Final</version>
        <type>pom</type>
    </dependency>
    <!-- Hibernate uses slf4j for logging -->
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-simple</artifactId>
        <version>1.7.5</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.14</version>
    </dependency>
</dependencies>

注意：非常感谢您的帮助。