Java JPA未持久化对象J2EE
我有一个使用JEE5的遗留应用程序,我添加了一个类“People”,并在数据库中添加了很多记录(People只有peopleid和字符串peopledesc) 如果我使用getAllPeople()方法正确填充列表,则所有数据都在那里 但是当我试图通过使用persistPeople(People-pep)的代码来持久化一个新记录时,它什么也做不了 system.out.println显示添加到对象的描述,以便将新创建的对象传递给方法,但它不会持久化到数据库中:( 控制台输出中未显示任何错误 People.javaJava JPA未持久化对象J2EE,java,jpa,Java,Jpa,我有一个使用JEE5的遗留应用程序,我添加了一个类“People”,并在数据库中添加了很多记录(People只有peopleid和字符串peopledesc) 如果我使用getAllPeople()方法正确填充列表,则所有数据都在那里 但是当我试图通过使用persistPeople(People-pep)的代码来持久化一个新记录时,它什么也做不了 system.out.println显示添加到对象的描述,以便将新创建的对象传递给方法,但它不会持久化到数据库中:( 控制台输出中未显示任何错误 Pe
@Entity
public class People implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int idpeople;
private String desc;
persistence.xml
<persistence-unit name="PersistenceUnit" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<class>entities.People</class>
org.hibernate.ejb.HibernatePersistence
实体、人
PeopleDAOImPL.JAVA
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;
import javax.persistence.PersistenceContext;
import javax.persistence.PersistenceUnit;
import residencias.dominio.Renovacion;
@Stateless
public class PeopleDAOImpl implements PeopleDAO {
//EntityManagerFactory emf = Persistence.createEntityManagerFactory("PersistenceUnit");
@PersistenceUnit(unitName="PersistenceUnit")
private EntityManagerFactory emf;
@Override
public void persistPeople(People pep) {
EntityManager em = emf.createEntityManager();
System.out.println("description is :"+pep.getDesc());
em.persist(pep);
}
@Override
public List<People> getAllPeople() {
EntityManager em = emf.createEntityManager();
List<People> results = new ArrayList();
Query queryPrincipal;
try {
queryPrincipal = em.createQuery("SELECT p FROM People p");
results = queryPrincipal.getResultList();
return results;
} catch (Exception e) {
System.out.println(results.size());
return results;
} finally {
if (em != null) {
emf.close();
em.close();
}
}
}
PeopleDAOImPL.JAVA
导入javax.ejb.Stateless;
导入javax.persistence.EntityManager;
导入javax.persistence.EntityManagerFactory;
导入javax.persistence.EntityTransaction;
导入javax.persistence.persistence;
导入javax.persistence.PersistenceContext;
导入javax.persistence.PersistenceUnit;
多米尼奥·雷诺瓦西翁进口公寓;
@无国籍
公共类PeopleDAOImpl实现PeopleDAO{
//EntityManagerFactory emf=Persistence.createEntityManagerFactory(“PersistenceUnit”);
@PersistenceUnit(unitName=“PersistenceUnit”)
私人实体管理工厂emf;
@凌驾
公众人物(pep){
EntityManager em=emf.createEntityManager();
System.out.println(“说明为:+pep.getDesc());
em.persist(pep);
}
@凌驾
公共列表getAllPeople(){
EntityManager em=emf.createEntityManager();
列表结果=新建ArrayList();
查询查询原则;
试一试{
queryPrincipal=em.createQuery(“从人员p中选择p”);
结果=queryPrincipal.getResultList();
返回结果;
}捕获(例外e){
System.out.println(results.size());
返回结果;
}最后{
如果(em!=null){
emf.close();
em.close();
}
}
}
在调用查询期间,您不必在事务中运行,当您尝试持久化/更新实体状态时,您必须在事务边界内运行该特定操作
在您的情况下,可以使用以下配置:
@Stateless
@TransactionManagement(TransactionManagementType.CONTAINER)
public class PeopleDAOImpl implements PeopleDAO {
@PersistenceUnit(unitName="PersistenceUnit")
private EntityManagerFactory emf;
@Override
@TransactionAttribute(TransactionAttributeType.REQUIRED)
public void persistPeople(People pep) {
EntityManager em = emf.createEntityManager();
System.out.println("description is :"+pep.getDesc());
em.persist(pep);
}
感谢您的回答,我尝试了您的解决方案,但在调用EntityManager em=emf.createEntityManager()时出现了空指针异常;