这是我的第一个Hibernate应用程序。我在执行主类时遇到了这个错误。我试图在表学生中插入新记录。还可以说hibernate在没有任何问题的情况下连接到数据库!我不断得到这个MappingException:
Hibernate: drop table if exists student
Hibernate: create table student (student_id integer not null auto_increment, First_Name varchar(255), Last_Name varchar(255), Age integer, primary key (student_id))
Dec 22, 2015 10:04:44 PM org.hibernate.tool.hbm2ddl.SchemaExport execute
INFO: HHH000230: Schema export complete
Exception in thread "main" org.hibernate.MappingException: Unknown entity: org.hibernate.internal.SessionImpl
at org.hibernate.internal.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:1146)
at org.hibernate.internal.SessionImpl.getEntityPersister(SessionImpl.java:1358)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:116)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:206)
at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:55)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:191)
at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:49)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:90)
at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:683)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:675)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:671)
at biztime.Manager.main(Manager.java:23)
有没有人有任何想法,因为我看了很多重复,但决议似乎对我不起作用。这是我的cfg.xml
我的hibernate.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="dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">root</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/anwardb</property>
<property name="hibernate.show_sql">true</property>
<property name="hibernate.hbm2ddl.auto">create-drop</property>
<!-- <property name="hibernate.hbm2ddl.auto">update</property> -->
<mapping resource="biztime/student.hbm.xml"/>
</session-factory>
</hibernate-configuration>
我的student.java
package biztime;
public class student
{
private int student_id;
private String First_Name;
private String Last_Name;
private int Age;
public int getStudent_id()
{
return student_id;
}
public void setStudent_id(int student_id)
{
this.student_id = student_id;
}
public String getFirst_Name()
{
return First_Name;
}
public void setFirst_Name(String first_Name)
{
First_Name = first_Name;
}
public String getLast_Name()
{
return Last_Name;
}
public void setLast_Name(String last_Name)
{
Last_Name = last_Name;
}
public int getAge()
{
return Age;
}
public void setAge(int age)
{
Age = age;
}
}
student.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="biztime">
<class name="student" table="student ">
<id name="student_id" column="student_id">
<generator class="native"/>
</id>
<property name="First_Name" >
<column name="First_Name"/>
</property>
<property name="Last_Name">
<column name="Last_Name"/>
</property>
<property name="Age">
<column name="Age"/>
</property>
</class>
</hibernate-mapping>
我用这个主要来称呼它:
Manager.java
package biztime;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class Manager
{
public static void main(String[] args)
{
Configuration con=new Configuration();
con.configure();
SessionFactory sf=con.buildSessionFactory();
Session s1=sf.openSession();
student s=new student ();
s.setFirst_Name("hello");
s.setLast_Name("test");
s.setStudent_id(1);
s.setAge(20);
s1.beginTransaction();
s1.save(s1);
s1.getTransaction().commit();
s1.flush();
s1.close();
System.out.println("done");
}
}
答案 0 :(得分:1)
您正在尝试保存s1
Session
。保存s
,即student
(并将您的类名称大写)。
答案 1 :(得分:0)
我认为你不应该设置student_id,因为它是auto_increment
字段。请尝试删除此行:s.setStudent_id(1);