脱离容器 使用 jpa persistence.xml 模板 上面用的数据库是Derby

 <?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0"
 xmlns="http://java.sun.com/xml/ns/persistence"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd ">
 <persistence-unit name="pu1" transaction-type="RESOURCE_LOCAL">
  <provider>org.hibernate.ejb.HibernatePersistence</provider>
  <class>entity.Student</class>
  <properties>
   <property name="hibernate.connection.driver_class" value="org.apache.derby.jdbc.ClientDriver"/>
   <property name="hibernate.connection.url" value="jdbc:derby://localhost:1527/luyu"/>
   <property name="hibernate.connection.username" value="app"/>
   <property name="hibernate.connection.password" value="app"/>
   <property name="hibernate.dialect" value="org.hibernate.dialect.DerbyDialect"/>
   <property name="hibernate.show_sql" value="true"/>
   <property name="hibernate.hbm2ddl.auto" value="create"/>
  </properties>
 </persistence-unit>
</persistence>

 

package dao;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;

import entity.Student;

public class StudentDaoJpa implements StudentDao {
 
 static EntityManagerFactory  emf = Persistence.createEntityManagerFactory("pu1");
 public Student add(Long id,String name) {
  EntityManager em = emf.createEntityManager();
  Student stu = new Student();
  stu.setName(name);
  stu.setId(id);
  try{
   em.getTransaction().begin();
   em.persist(stu);
   em.getTransaction().commit();
   return stu;
  }catch(Exception e){
   e.printStackTrace();
   em.getTransaction().rollback();
   return null;
  }finally{
   em.close();
   emf.close();
  }
 }
 
}