使用hibernate4报错
Initial SessionFactory creation failed.java.lang.NullPointerException
Exception in thread "main" java.lang.ExceptionInInitializerError
at HibernateUtil.buildSessionFactory(HibernateUtil.java:22)
at HibernateUtil.(HibernateUtil.java:9)
at TestStudent.main(TestStudent.java:22)
Caused by: java.lang.NullPointerException
at HibernateUtil.buildSessionFactory(HibernateUtil.java:16)
... 2 more
mysql—connector-java使用的版本是5.1.22
hibernate使用的版本是4.3.5
以下是程序：
TestStudent.java
import javax.imageio.spi.ServiceRegistry;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import com.bjsxt.hibernate.model.Student;
public class TestStudent {
public static void main(String args[]){
Student s=new Student();
s.setId(1);
s.setName("s1");
s.setAge(1);
SessionFactory sf=HibernateUtil.getSessionFactory();
Session session=sf.openSession();
session.beginTransaction();
session.save(s);
session.getTransaction().commit();
session.close();
sf.close();
}
}
HibernateUtil.java
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
private static final SessionFactory sessionFactory = buildSessionFactory();
private static Configuration cfg=new Configuration();
private static SessionFactory buildSessionFactory() {
try {
return cfg.configure().buildSessionFactory(new StandardServiceRegistryBuilder().build());
}
catch (Throwable ex) {
// Make sure you log the exception, as it might be swallowed
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
}
hibernate.cfg.xml
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<session-factory>
<property name="javax.persistence.validation.mode">none</property>
<!-- Database connection settings -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost/hibernate</property>
<property name="connection.username">ru</property>
<property name="connection.password">qq</property>
<!-- JDBC connection pool (use the built-in) -->
<!--<property name="connection.pool_size">1</property>-->
<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<!-- Enable Hibernate's automatic session context management -->
<!--<property name="current_session_context_class">thread</property>-->
<!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>
<!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>
<!-- Drop and re-create the database schema on startup -->
<!--<property name="hbm2ddl.auto">update</property>-->
<mapping resource="com/bjsxt/hibernate/model/Student.hbm.xml"/>
</session-factory>
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">
