在一个简单的 maven hibernate 项目中出现错误“java.lang.NoClassDefFoundError: org/hibernate/cfg/Mappings”

Question

我正在开发一个使用 maven、hibernate 和 mysql 的项目。这是我的 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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.heroku.realstate</groupId>
    <artifactId>realstate-database</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.38</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.1.0.Final</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>5.1.0.Final</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>ejb3-persistence</artifactId>
            <version>1.0.2.GA</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-tools</artifactId>
            <version>4.3.2.Final</version>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-annotations</artifactId>
            <version>3.5.6-Final</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-commons-annotations</artifactId>
            <version>3.2.0.Final</version>
        </dependency>

    </dependencies>

</project>

这是我的资源/hibernate.cfg.xml：

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/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/$DATABASE_NAME
        </property>
        <property name="hibernate.connection.password">
            $PASSWORD
        </property>
        <property name="hibernate.connection.username">
            @USERNAME
        </property>
        <property name="hibernate.dialect">
            org.hibernate.dialect.MySQLDialect
        </property>
        <property name="show_sql">
            true
        </property>
        <property name="hbm2ddl.auto">
            create
        </property>

        <mapping class="com.heroku.realstate.database.user.UserEntity"/>
        <mapping class="com.heroku.realstate.database.user.ClientEntity"/>
        <mapping class="com.heroku.realstate.database.user.BotEntity"/>
        <mapping class="com.heroku.realstate.database.sms.SmsEntity"/>

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

我已经安装了 mysql 并创建了一个名为 $DATABASE_NAME 的数据库，但我还没有在数据库中创建任何表（因为我不是 sql 专家，我希望 hibernate 可以为像我这样的人做这件事！）。这是我使用休眠的方式：

class HibernateUtils {

    private static final SessionFactory sessionFactory = buildSessionFactory();

    private static SessionFactory buildSessionFactory() {
        // Create the SessionFactory from hibernate.cfg.xml
        return new AnnotationConfiguration().configure(new File("hibernate.cfg.xml")).buildSessionFactory();
    }

    static SessionFactory getSessionFactory() {
        return sessionFactory;
    }
    static void shutdown() {
        // Close caches and connection pools
        getSessionFactory().close();
    }

我通过 maven 构建了这个项目，它成功构建了。但是当我运行应用程序时，JVM 给了我错误：java.lang.NoClassDefFoundError: org/hibernate/cfg/Mappings 在这一行：

return new AnnotationConfiguration().configure(new File("hibernate.cgf.xml")).buildSessionFactory();

有什么问题？我应该如何解决它？谢谢！

Answer 1

尝试替换这一行：

  return new AnnotationConfiguration().configure(new File("hibernate.cgf.xml")).buildSessionFactory();

与：

   return new Configuration().configure().buildSessionFactory();

因为Deprecated。使用给定应用程序文件中指定的映射和属性。

欲了解更多信息，请转到AnnotationConfiguration

Answer 2

图书馆的问题。你使用 Hibernate 5。所以你在pom.xml 中不需要这个

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>ejb3-persistence</artifactId>
            <version>1.0.2.GA</version>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-annotations</artifactId>
            <version>3.5.6-Final</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-commons-annotations</artifactId>
            <version>3.2.0.Final</version>
        </dependency>

Hibernate 5 使用hibernate-commons-annotations-5.0.1.Final.jar，您不需要指定它。因为，它是一个传递依赖。

你也不需要它，因为你不使用JPA

   <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-entitymanager</artifactId>
        <version>5.1.0.Final</version>
   </dependency>

Hibernate 4 和 Hibernate 5 中没有AnnotationConfiguration。它是从 Hibernate 3 形成的！

配置 Hibernate 5

 private static SessionFactory buildSessionFactory() {
    return new Configuration().configure().buildSessionFactory();
 }

Answer 3

如果您使用高于版本 3 的 Hibernate（如构建版本 4 或 5），只需使用 Configuration 而不是 AnnotationConfiguration 类，因为 AnnotationConfiguration 已删除版本 3 之后。

让我们有一个包含 11 个依赖项和配置的快照示例，以使用基于注解的映射配置。

1.  antlr-2.7.7.jar
2.  classmate-1.3.0.jar
3.  dom4j-1.6.1.jar
4.  geronimo-jta_1.1_spec-1.1.1.jar
5.  hibernate-commons-annotations-5.0.1.Final.jar
6.  hibernate-core-5.1.10.Final.jar
7.  hibernate-jpa-2.1-api-1.0.0.Final.jar
8.  jandex-2.0.3.Final.jar
9.  javassist-3.20.0-GA.jar
10. jboss-logging-3.3.0.Final.jar
11. mysql-connector-java-5.1.38-bin.jar

配置文件如下：

<hibernate-configuration>
<session-factory>
    <property name="hibernate.connection.driver.class">com.mysql.jdbc.Driver</property>
    <property name="hibernate.connection.url">jdbc:mysql://zampylob:3306/hibernatedb</property>
    <property name="hibernate.connection.username">hiberuser</property>
    <property name="hibernate.connection.password">XXXXXXXXXX</property>
    <property name="hibernate.connection.dialect">org.hibernate.dialect.MySQLDialect</property>
    <property name="hibernate.connection.show_sql">true</property>
    <property name="hibernate.connection.format_sql">true</property>
    <property name="hibernate.hbm2ddl.auto">create</property>

    <mapping class="com.whodesire.model.Student" />
</session-factory>
</hibernate-configuration>

学生POJO课是：

import java.util.Date;

import javax.persistence.Entity;
import javax.persistence.Id;

@Entity
public class Student {

    @Id
    private Integer rollNo;

    private String firstName;
    private String middleName;
    private String lastName;
    private Date dateOfBirth;
    private String gender;

    public Integer getRollNo() {
        return rollNo;
    }

    public void setRollNo(Integer rollNo) {
        this.rollNo = rollNo;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getMiddleName() {
        return middleName;
    }

    public void setMiddleName(String middleName) {
        this.middleName = middleName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public Date getDateOfBirth() {
        return dateOfBirth;
    }

    public void setDateOfBirth(Date dateOfBirth) {
        this.dateOfBirth = dateOfBirth;
    }
}

最后主类是：

SessionFactory factory = new Configuration().configure("resources/hibernate.cfg.xml").buildSessionFactory();
Session session = factory.openSession();
Transaction transaction = session.beginTransaction();

Student student = new Student();
student.setRollNo(1002);
student.setFirstName("Maaherin");
student.setMiddleName("Zubbair");
student.setLastName("Gulfam");
student.setDateOfBirth(new Date());
student.setGender("Male");

session.persist(student);
transaction.commit();
session.close();