[英]Hibernate + PostgreSQL throws an Exception: Unknown entity
I write a java maven project for restful webservice
using jersey + hibernate
and having below error
: 我使用jersey + hibernate
编写了一个用于宁静webservice
的Java Maven项目,并出现以下error
:
javax.servlet.ServletException: org.hibernate.MappingException: Unknown entity: org.asad.dto.logindetail javax.servlet.ServletException:org.hibernate.MappingException:未知实体:org.asad.dto.logindetail
org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:419) org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:419)
org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java: 381) org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:344) org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:381)org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:344)
org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java: 221) org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:221)
hibernate.cfg.xml File: hibernate.cfg.xml文件:
<?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>
<!-- Database connection settings -->
<property name="connection.driver_class">org.postgresql.Drive</property>
<property
name="connection.url">jdbc:postgresql://localhost:5432/logindb</property>
<property name="connection.username">postgres</property>
<property name="connection.password">project</property>
<!-- JDBC connection pool (use the built-in) -->
<property name="connection.pool_size">1</property>
<!-- SQL dialect -->
<property
name="dialect">org.hibernate.dialect.PostgreSQLDialect</property>
<!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.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>
<propertyname="connection.driver_class">org.postgresql.Driver</property>
<!-- Names the annotated entity class -->
<mapping class="org.asad.dto.logindetail"/>
</session-factory>
</hibernate-configuration>
The table name is "logindetail". 表名是“ logindetail”。
Database Class: 数据库类:
@Entity
@Table (name = "logidetail") public class logindetail {
@Id
int userId;
String name;
String password;
public void setUserId(int i){
this.userId = i;
}
public int getUserId(){
return userId;
}
public void setName(String name){
this.name = name;
}
public String getName(){
return name;
}
public void setPassword(String pass){
this.password = pass;
}
public String getPassword(){
return password;
}}
Main Class: 主类:
package org.asad.login.login.loginservice;
import java.util.ArrayList;
import javax.management.Query;
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.ValidatorFactory;
import org.asad.dto.logindetail;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configurationimport org.hibernate.classic.Session;
public class LoginService{
SessionFactory sessionFactory = null;
Session session = null;
public String getDatabaseUser(){
logindetail user = null;
String name=null;try{
sessionFactory = new Configuration().configure().buildSessionFactory();
session = sessionFactory.openSession();
session.beginTransaction();
user = (logindetail)session.get(logindetail.class, 2);
name = user.getName();
session.getTransaction().commit();
session.close();
}catch(Exception e){
e.printStackTrace();
}
return name;
}}
now this error is coming java.lang.NullPointerException
anyone can help me to eliminate this error i will b thankful :) 现在此错误即将到来java.lang.NullPointerException
任何人都可以帮助我消除此错误,我将感激:)
Can you check if you imported correct @Entity
annotation. 您可以检查是否导入了正确的@Entity
批注。
As @Entity
comes under two packages one is org.hibernate.annotations.Entity
and other one with javax.persistence.Entity
. 由于@Entity
属于两个包,一个是org.hibernate.annotations.Entity
,另一个是javax.persistence.Entity
。
Use javax.persistence.Entity
to annotate your entity beans. 使用javax.persistence.Entity
注释您的实体bean。 Don't import org.hibernate.annotations.Entity
. 不要导入org.hibernate.annotations.Entity
。
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