今天在使用hibernate注解方式标明的实体类时产生数据库表示遇到了一些问题，经过搜集一些资料，最后总结了一下，如下所示：

先把我的整体的几个文件的代码贴出来吧

这是hibernate.cfg.xml文件

? ? ? ? ? "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
? ? ? ? ? "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

?
? com.mysql.jdbc.Driver
? jdbc:mysql://localhost:3306/phn_dsjava
? root
? 123456
? org.hibernate.dialect.MySQLDialect
? true
? true
? update

?

?

这是实体类Announces.java

package com.phn.bean;

import java.util.Date;

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

/**
?* @author phn
?*
?*/
@Entity
@Table(name = "t_announce")
public class Announces {

?private Integer id;
?private String announcement;
?private String title;
?private Date thetime;

?@Id
?@GeneratedValue
?@Column(nullable = false)
?public Integer getId() {
? return this.id;
?}

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

?@Column(length = 20000)
?public String getAnnouncement() {
? return this.announcement;
?}

?public void setAnnouncement(String announcement) {
? this.announcement = announcement;
?}

?@Column(length = 100)
?public String getTitle() {
? return title;
?}

?public void setTitle(String title) {
? this.title = title;
?}

?public Date getThetime() {
? return thetime;
?}

?public void setThetime(Date thetime) {
? this.thetime = thetime;
?}

}

这是测试类HibernateAnnotationTest.java

package com.phn.junitTest;

import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;
import org.junit.Test;

import junit.framework.TestCase;

public class HibernateAnnotationTest extends TestCase {
?@Test
?public void testSQL() {
? AnnotationConfiguration configuration = new AnnotationConfiguration();
? configuration.configure();
? SessionFactory sessionFactory = configuration.buildSessionFactory();
?}
}

---------------------------下面是大致问题解释---------------------------

Hibernate的配置文件hibernate.cfg.xml位于src目录下。在单元测试时，执行下面代码时，会产生异常。

Configuration cfg = new Configuration();
SessionFactory sf = cfg.configure().buildSessionFactory();

异常：
org.hibernate.MappingException: An AnnotationConfiguration instance is required to use

Hibernate配置文件中，若带有，则说明映射类时，采用了Annotation方式。在初始化Configuation时，应使用AnnoationConfiguration，代码如下：

AnnotationConfiguration configuration = new AnnotationConfiguration();
configuration.configure();
SessionFactory sessionFactory = configuration.buildSessionFactory();

注意：这里使用的hibernate版本是3.3
版本低一点可能会出现下面图片这个错误，这是因为低版本的hibernate的jar包org.hibernate.engine.query.sql.NativeSQLQueryReturn类缺少，因此将其版本更新一下就行了