Question

我刚刚开始学习Hibernate。为此，我编写了一个简单的Java程序。但是当我尝试执行程序时，我会遇到异常。

Apr 30, 2014 1:54:18 PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {4.0.4.Final}
Apr 30, 2014 1:54:18 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {4.3.5.Final}
Exception in thread "main" java.lang.ExceptionInInitializerError
    at org.hibernate.cfg.Configuration.reset(Configuration.java:324)
    at org.hibernate.cfg.Configuration.<init>(Configuration.java:289)
    at org.hibernate.cfg.Configuration.<init>(Configuration.java:293)
    at com.hiber.main.Main.main(Main.java:19)
Caused by: java.lang.NullPointerException
    at org.hibernate.internal.util.ConfigHelper.getResourceAsStream(ConfigHelper.java:170)
    at org.hibernate.cfg.Environment.<clinit>(Environment.java:221)
    ... 4 more

以下是该计划：

package com.hiber.main;

import javax.naming.NamingException;

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

public class Main {

    public static void main(String[] args) throws NamingException {
        //SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory(new StandardServiceRegistryBuilder().build());

        ServiceRegistry serviceRegistry;
        SessionFactory sessionFactory;

        Configuration configuration = new Configuration();
        configuration.configure("/com/hiber/main/hibernate.cfg.xml");
        serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();
        sessionFactory = configuration.buildSessionFactory(serviceRegistry);

        Session sess = sessionFactory.getCurrentSession();
        sessionFactory.openSession();
        sess.beginTransaction();

        Test1 t = new Test1();
        t.setTest1Ind(1);
        t.setName("name");
        t.setPassword("abcd1234");
        sess.saveOrUpdate(t);

        sess.getTransaction().commit();
        sess.close();


    }

}

以下是cfg xml：

<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "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.password">root1234</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/test</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.default_schema">test</property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="current_session_context_class">thread</property>
    </session-factory>
</hibernate-configuration>

我已经包含了所有依赖项。希望我没有错过任何东西。目前无法添加图片。

请任何人看看代码，并考虑一下这里可能出现的问题。提前谢谢。

Answer 1

在类路径中使用hibernate.cfg.xml并尝试使用这样的代码

Configuration configuration = new Configuration().configure();
        ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();
            sessionFactory = configuration.buildSessionFactory(serviceRegistry);

例如，如果您使用maven，它将位于\src\main\resources\hibernate.cfg.xml

位置

<强>更新

检查您是否具有正确的依赖关系（jar）。我在我的maven项目中有这些依赖项

enter image description here

Answer 2

完成本教程here

使用Annotation逐步进行Hibernate Mapping。

Answer 3

我想你忘记了hibernate cfg的映射类。

在标记

之前添加映射类

</session-factory>

在您的hibernate cfg上，不要忘记在课堂上添加注释。

，映射如下所示：

<mapping class="Curriculums"/>
<mapping class="CurriculumsHasStudentId"/>
<mapping class="Students"/>

带有注释的java类如下所示：

@Entity
@Table(name = "students")
public class Students implements Serializable{

@Id
@Column(name="studentsNrp", unique=true)
private String studentsNrp;

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

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

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

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

Answer 4

1删除项目中的依赖项。 2添加正确的依赖项（jar）。

启动时出现Hibernate异常

4 个答案: