初学hibernate框架，看视频半小时以为会了，排错一天了都没有结果，求指点！！！

参照视频写完配置文件，映射文件，持久类，还有数据库表之后想小试牛刀，点Test方法运行为JUNIT的频繁出错，到处碰壁呀，求救求指点！！！

持久类：

package po;

import java.io.Serializable;

public class User implements Serializable {
	private static final long serialVersionUID = 1L;
	private String userName;
	public User(){
		
	}
	public User(int i){
		
	}
	public String getUserName() {
		return userName;
	}
	public void setUserName(String userName) {
		this.userName = userName;
	}

}

配置文件：

<?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>
		<!-- 数据库连接 -->
		<property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
		<property name="connection.url">jdbc.oracle.thin:@localhost:1521:orcl<!-- :///hibernate?useUnicode=trup&amp;characterEncoding=UTF-8 --></property>
		<property name="connection.username">MKADMIN</property>
		<property name="connection.password">MK123456</property>
		<!-- 辅助参数 -->
		<property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>
		<property name="show_sql">true</property>
		<property name="format_sql">true</property>
		<property name="htm2ddl.auto">create</property><!-- DDL语句生成策略 -->
		<property name="current_session_context_class">true</property>
		<!-- 映射文件 -->
		<mapping resource="User.hbm.xml" />
	</session-factory>
</hibernate-configuration>

映射文件：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
	<class	name="po.User" table="users">
	<id name="userName" type="java.lang.String">
		<column name="username" length="10" />
	</id>
	</class>
</hibernate-mapping>

测试类：

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import po.User;
public class UserTest {
	private SessionFactory sf=null;
	private Session session=null;
	private Transaction tran=null;
	@Before
	public void init(){
		//创建配置对象
		Configuration cfg=new Configuration().configure();
		//创建注册服务对象
		ServiceRegistry serviceRegistry=new ServiceRegistryBuilder().applySettings(cfg.getProperties()).buildServiceRegistry();
		//创建工厂对象
		sf=cfg.buildSessionFactory(serviceRegistry);
		//创建会话对象
		session=sf.getCurrentSession();
		//开启事务
		tran=session.beginTransaction();
	}
	@After
	public void destroy(){
		//释放资源之前需先提交事务
		tran.commit();
		session.close();
		sf.close();
	}
	@Test
	public void userTest(){
		//生成用户对象
		User su=new User();
		su.setUserName("zhangsanfeng");
		session.save(su);
	}
}

数据库SQL语句

-- Create table

create table USERS

(

username VARCHAR2(10) not null constraint PK_USERS primary key

)

控制台信息：

2017-5-3 18:51:04 org.hibernate.annotations.common.Version <clinit>

INFO: HCANN000001: Hibernate Commons Annotations {4.0.2.Final}

2017-5-3 18:51:04 org.hibernate.Version logVersion

INFO: HHH000412: Hibernate Core {4.2.4.Final}

2017-5-3 18:51:04 org.hibernate.cfg.Environment <clinit>

INFO: HHH000206: hibernate.properties not found

2017-5-3 18:51:04 org.hibernate.cfg.Environment buildBytecodeProvider

INFO: HHH000021: Bytecode provider name : javassist

2017-5-3 18:51:04 org.hibernate.cfg.Configuration configure

INFO: HHH000043: Configuring from resource: /hibernate.cfg.xml

2017-5-3 18:51:04 org.hibernate.cfg.Configuration getConfigurationInputStream

INFO: HHH000040: Configuration resource: /hibernate.cfg.xml

2017-5-3 18:51:04 org.hibernate.internal.util.xml.DTDEntityResolver resolveEntity

WARN: HHH000223: Recognized obsolete hibernate namespace http://hibernate.sourceforge.net/. Use namespace http://www.hibernate.org/dtd/ instead. Refer to Hibernate 3.6 Migration Guide!

2017-5-3 18:51:04 org.hibernate.cfg.Configuration addResource

INFO: HHH000221: Reading mappings from resource: User.hbm.xml

2017-5-3 18:51:04 org.hibernate.internal.util.xml.DTDEntityResolver resolveEntity

WARN: HHH000223: Recognized obsolete hibernate namespace http://hibernate.sourceforge.net/. Use namespace http://www.hibernate.org/dtd/ instead. Refer to Hibernate 3.6 Migration Guide!

2017-5-3 18:51:04 org.hibernate.cfg.Configuration doConfigure

INFO: HHH000041: Configured SessionFactory: null