Question

您好我是hibernate框架的新手。当我运行hibernate示例代码时，如果互联网连接可用，它工作正常。如果互联网连接不可用，那么它不起作用，并给出如下错误：

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
Failed to create sessionFactory object.org.hibernate.HibernateException: Could not parse configuration: /hibernate.cfg.xml
Exception in thread "main" java.lang.ExceptionInInitializerError
    at com.hb.example.ManageEmployee.main(ManageEmployee.java:20)
Caused by: org.hibernate.HibernateException: Could not parse configuration: /hibernate.cfg.xml
    at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1491)
    at org.hibernate.cfg.Configuration.configure(Configuration.java:1425)
    at org.hibernate.cfg.Configuration.configure(Configuration.java:1411)
    at com.hb.example.ManageEmployee.main(ManageEmployee.java:17)
Caused by: org.dom4j.DocumentException: www.hibernate.org Nested exception: www.hibernate.org
    at org.dom4j.io.SAXReader.read(SAXReader.java:484)
    at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1481)
    ... 3 more

我的示例代码如下所示： Employee.java：

package com.hb.example;

public class Employee {
       private int id;
       private String firstName; 
       private String lastName;   
       private int salary;  

       public Employee() {}
       public Employee(String fname, String lname, int salary) {
          this.firstName = fname;
          this.lastName = lname;
          this.salary = salary;
       }
       public int getId() {
          return id;
       }
       public void setId( int id ) {
          this.id = id;
       }
       public String getFirstName() {
          return firstName;
       }
       public void setFirstName( String first_name ) {
          this.firstName = first_name;
       }
       public String getLastName() {
          return lastName;
       }
       public void setLastName( String last_name ) {
          this.lastName = last_name;
       }
       public int getSalary() {
          return salary;
       }
       public void setSalary( int salary ) {
          this.salary = salary;
       }
    }

ManageEmployee.java：

package com.hb.example;

import java.util.List; 
import java.util.Date;
import java.util.Iterator; 

import org.hibernate.HibernateException; 
import org.hibernate.Session; 
import org.hibernate.Transaction;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class ManageEmployee {
   private static SessionFactory factory; 
   public static void main(String[] args) {
      try{
         factory = new Configuration().configure().buildSessionFactory();
      }catch (Throwable ex) { 
         System.err.println("Failed to create sessionFactory object." + ex);
         throw new ExceptionInInitializerError(ex); 
      }
      ManageEmployee ME = new ManageEmployee();

      /* Add few employee records in database */
      Integer empID1 = ME.addEmployee("Zara", "Ali", 1000);
      Integer empID2 = ME.addEmployee("Daisy", "Das", 5000);
      Integer empID3 = ME.addEmployee("John", "Paul", 10000);

      /* List down all the employees */
      ME.listEmployees();

      /* Update employee's records */
      ME.updateEmployee(empID1, 5000);

      /* Delete an employee from the database */
      ME.deleteEmployee(empID2);

      /* List down new list of the employees */
      ME.listEmployees();
   }
   /* Method to CREATE an employee in the database */
   public Integer addEmployee(String fname, String lname, int salary){
      Session session = factory.openSession();
      Transaction tx = null;
      Integer employeeID = null;
      try{
         tx = session.beginTransaction();
         Employee employee = new Employee(fname, lname, salary);
         employeeID = (Integer) session.save(employee); 
         tx.commit();
      }catch (HibernateException e) {
         if (tx!=null) tx.rollback();
         e.printStackTrace(); 
      }finally {
         session.close(); 
      }
      return employeeID;
   }
   /* Method to  READ all the employees */
   public void listEmployees( ){
      Session session = factory.openSession();
      Transaction tx = null;
      try{
         tx = session.beginTransaction();
         List employees = session.createQuery("FROM Employee").list(); 
         for (Iterator iterator = 
                           employees.iterator(); iterator.hasNext();){
            Employee employee = (Employee) iterator.next(); 
            System.out.print("First Name: " + employee.getFirstName()); 
            System.out.print("  Last Name: " + employee.getLastName()); 
            System.out.println("  Salary: " + employee.getSalary()); 
         }
         tx.commit();
      }catch (HibernateException e) {
         if (tx!=null) tx.rollback();
         e.printStackTrace(); 
      }finally {
         session.close(); 
      }
   }
   /* Method to UPDATE salary for an employee */
   public void updateEmployee(Integer EmployeeID, int salary ){
      Session session = factory.openSession();
      Transaction tx = null;
      try{
         tx = session.beginTransaction();
         Employee employee = 
                    (Employee)session.get(Employee.class, EmployeeID); 
         employee.setSalary( salary );
         session.update(employee); 
         tx.commit();
      }catch (HibernateException e) {
         if (tx!=null) tx.rollback();
         e.printStackTrace(); 
      }finally {
         session.close(); 
      }
   }
   /* Method to DELETE an employee from the records */
   public void deleteEmployee(Integer EmployeeID){
      Session session = factory.openSession();
      Transaction tx = null;
      try{
         tx = session.beginTransaction();
         Employee employee = 
                   (Employee)session.get(Employee.class, EmployeeID); 
         session.delete(employee); 
         tx.commit();
      }catch (HibernateException e) {
         if (tx!=null) tx.rollback();
         e.printStackTrace(); 
      }finally {
         session.close(); 
      }
   }
}

hibernate.cfg.xml中：

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

＆LT; -----＆GT;

＆lt; - ---＆gt;

<hibernate-configuration>
   <session-factory>
   <property name="hbm2ddl.auto">update</property>
   <property name="hibernate.dialect">
      org.hibernate.dialect.MySQLDialect
   </property>
   <property name="hibernate.connection.driver_class">
      com.mysql.jdbc.Driver
   </property>

   <!-- Assume test is the database name -->
   <property name="hibernate.connection.url">
      jdbc:mysql://localhost/test
   </property>
   <property name="hibernate.connection.username">
      root
   </property>
   <property name="hibernate.connection.password">
      root
   </property>

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

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

Employee.hbm.xml：

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

我在这里完成了修改，但它无法正常工作

＆LT; --- ---＆GT;

<hibernate-mapping>
   <class name="com.hb.example.Employee" table="EMPLOYEE">
      <meta attribute="class-description">
         This class contains the employee detail. 
      </meta>
      <id name="id" type="int" column="id">
         <generator class="native"/>
      </id>
      <property name="firstName" column="first_name" type="string"/>
      <property name="lastName" column="last_name" type="string"/>
      <property name="salary" column="salary" type="int"/>
   </class>
</hibernate-mapping>

任何人都可以帮助我。

Answer 1

见第3＆amp;你的休眠配置中的第4行＆amp;分别映射文件。

DTD的文件说：

Hibernate不会从网上加载DTD文件，但首先要查看它从应用程序的类路径。 DTD文件包含在 hibernate-core.jar（它也包含在hibernate3.jar中，如果使用分发包）。

你在没有互联网的情况下得到了这个例外，因为它主要试图为hibernate配置加载DTD文件。在应用程序中映射来自Internet的文件。

当您的应用程序启动时＆amp;它第一次访问hibernate配置文件时，会尝试使用DTD文件解析配置文件，该文件从 www.hibernate.org 下载。

有关Hiberate DTD的更多信息，请查看以下内容：

http://forum.spring.io/forum/spring-projects/data/73208-how-to-configure-hibernate-cfg-xml-to-work-offline

http://docs.jboss.org/hibernate/orm/3.3/reference/en/html/tutorial.html#tutorial-firstapp-mapping

更新： -

如何使用Hibernate离线？

对于Hibernate配置文件：

将DTD文件声明更改为

<!DOCTYPE hibernate-configuration SYSTEM "hibernate-configuration-3.0.dtd">
从以下网址下载hibernate配置DTD文件：http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd＆amp;将它设置为您的类路径。

对于hibernate映射文件：

将DTD文件声明更改为

<!DOCTYPE hibernate-configuration SYSTEM "hibernate-mapping-3.0.dtd">
从以下网址下载hibernate配置DTD文件：http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd＆amp;将它设置为您的类路径。

这应该可以正常工作。

Answer 2

我今天看到一个类似的问题，我回答。好像你的hbm文件也有DOCTYPE不匹配。检查一次。它应该工作。

Failed to create sessionFactory object.org.hibernate.InvalidMappingException: Could not parse mapping document from resource Employee.hbm.xml

使用以下doctype：

Answer 3

可能存在ManageEmployee.java无法填充配置（hibernate.cfg.xml）文件的情况。您可以添加以下代码来填充配置文件。

Configuration cfg=new Configuration();  //create Configuration object first

cfg.configure("hibernate.cfg.xml");//populates the data of the configuration file  
factory=cfg.buildSessionFactory(); //then u can create session factory object and u can begin your transaction

以下对我有用，希望它对你有用：）

无法创建sessionFactory object.org.hibernate.HibernateException

3 个答案: