hibernate MappingException:Unknown entity don't know why?

Question

i have a problem and i need your help.i use eclipse 4.5.1. hibernate5.1 and here is the code

Exception in thread "main" org.hibernate.MappingException: Unknown entity: net.runze.hb1.entity.News

 public class NewsManager { public static void main(String[] args) throws Exception { Configuration conf = new Configuration() .configure(); ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder() .applySettings(conf.getProperties()).build(); SessionFactory sf = conf.buildSessionFactory(serviceRegistry); Session sess = sf.openSession(); Transaction ta = sess.beginTransaction(); News n = new News(); n.setTitle("Aliens"); n.setContent("hahahaha!"); sess.save(n); // here is where it threw exception ta.commit(); sess.close(); sf.close(); } } 

and i use annotation to the entity class:

 import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.Table; @Entity @Table(name="news_inf") public class News { @Id @GeneratedValue(strategy=GenerationType.IDENTITY) private Integer id; private String title; private String content; // getters and setters... } 

here is my 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"> <hibernate-configuration> <session-factory> <property name="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url"> jdbc:mysql://localhost:3306/hibernate?useUnicode=true&amp;characterEncoding=UTF-8</property> <property name="connection.username">root</property> <property name="connection.password">123456</property> <property name="hibernate.c3p0.max_size">20</property> <property name="hibernate.c3p0.min_size">1</property> <property name="hibernate.c3p0.timeout">5000</property> <property name="hibernate.c3p0.max_statements">100</property> <property name="hibernate.c3p0.idle_test_period">3000</property> <property name="hibernate.c3p0.aquire_increment">2</property> <property name="hibernate.c3p0.validate">true</property> <property name="dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property> <property name="hbm2ddl.auto">update</property> <property name="show_sql">true</property> <property name="hibernate.format_sql">true</property> <property name="hibernate.temp.use_jdbc_metadata_defaults">false</property> <mapping class="net.runze.hb1.entity.News" /> </session-factory> </hibernate-configuration> 

they says this problem will happen when my @Entity import the wrong package,or the hibernate.cfg.xml forgot the "mapping". both them i made it right but it still don't work.

Answer 1

It is simply :)

Configuration conf = new Configuration()
                .configure();
        ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
                .applySettings(conf.getProperties()).build();

        SessionFactory sf = conf.buildSessionFactory(serviceRegistry);

Change to

SessionFactory sf = new Configuration().configure().buildSessionFactory();

Hibernate 5 :- org.hibernate.MappingException: Unknown entity

Answer 2

您必须指定配置文件的位置：

onfiguration conf = new Configuration().configure("[your package]/hibernate.cfg.xml");