Как сохранить объект в базе данных?

Question

У меня есть простой проект mvc Spring для добавления пользователей в базу данных. Я использую hibernate 4.1.9, Spring Framework 3.2.0 и PostgreSQL 9.2.

Смотрите мой код ниже

боба Пользователь

package org.vdzundza.beans; 

import javax.persistence.Column; 
import javax.persistence.Entity; 
import javax.persistence.GeneratedValue; 
import javax.persistence.GenerationType; 
import javax.persistence.Id; 
import javax.persistence.SequenceGenerator; 
import javax.persistence.Table; 

@Entity 
@Table(name = "users") 
public class User { 
    @Id 
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "user_seq") 
    @SequenceGenerator(name = "user_seq", sequenceName = "user_seq") 
    @Column(name = "id") 
    private Long id; 

    @Column(name = "network") 
    private String network; 

    @Column(name = "photo") 
    private String photo; 

    @Column(name = "identity") 
    private String identity; 

    @Column(name = "firstname") 
    private String firstName; 

    @Column(name = "lastname") 
    private String lastName; 

    @Column(name = "hash") 
    private String hash; 

    @Column(name = "isonline") 
    private Boolean isOnline; 

    public User() { 
    } 
    //getters and setters 

    @Override 
    public String toString(){ 
     StringBuilder out = new StringBuilder(); 
     out.append("["); 
     out.append("name: " + firstName + " " + lastName); 
     out.append("\tnetwork: " + network); 
     out.append("\t Is online: " + isOnline); 
     return out.toString(); 

    }   
} 

UserDAO

package org.vdzundza.dao; 

import java.util.List; 

import org.hibernate.SessionFactory; 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.stereotype.Repository; 
import org.vdzundza.beans.User; 

@Repository 
public class UserDAOImpl implements UserDao { 

    @Autowired 
    private SessionFactory sessionFactory; 

    @Override 
    public void addUser(User user) { 
     sessionFactory.openSession().save(user); 
    } 

    @SuppressWarnings("unchecked") 
    @Override 
    public List<User> listUser() { 
     return sessionFactory.openSession().createCriteria(User.class).list(); 
    } 
} 

UserService

package org.vdzundza.service; 

import java.util.List; 

import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.stereotype.Service; 
import org.springframework.transaction.annotation.Transactional; 
import org.vdzundza.beans.User; 
import org.vdzundza.dao.UserDao; 

@Service 
public class UserServiceImpl implements UserService { 

    @Autowired 
    private UserDao userDAO; 

    @Transactional 
    public void addUser(User user) { 
     userDAO.addUser(user); 
    } 

    @Transactional 
    public List<User> listUser() { 
     return userDAO.listUser(); 
    } 
} 

корня context.xml

<?xml version="1.0" encoding="UTF-8"?> 
<beans xmlns="http://www.springframework.org/schema/beans" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" 
    xmlns:p="http://www.springframework.org/schema/p" xmlns:c="http://www.springframework.org/schema/c" 
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd 
     http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd"> 

    <!-- Root Context: defines shared resources visible to all other web components --> 
    <context:annotation-config /> 
    <context:component-scan base-package="org.vdzundza.dao" /> 
    <context:component-scan base-package="org.vdzundza.service" /> 

    <bean id="propertiesConfig" 
     class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer" 
     p:location="/WEB-INF/jdbc.properties" /> 

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" 
     destroy-method="close"> 
     <property name="driverClassName" value="${jdbc.driverClassName}" /> 
     <property name="url" value="${jdbc.url}" /> 
     <property name="username" value="${jdbc.username}" /> 
     <property name="password" value="${jdbc.password}" /> 
    </bean> 

    <bean id="sessionFactory" 
     class="org.springframework.orm.hibernate4.LocalSessionFactoryBean" 
     lazy-init="false"> 
     <property name="dataSource" ref="dataSource" /> 
     <property name="hibernateProperties"> 
      <props> 
       <prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop> 
       <prop key="hibernate.show_sql">true</prop> 
       <prop key="hibernate.hbm2ddl.auto">update</prop> 
      </props> 
     </property> 
     <property name="packagesToScan" value="org.vdzundza.beans" /> 
    </bean> 

    <bean id="transactionalManager" 
     class="org.springframework.orm.hibernate4.HibernateTransactionManager"> 
     <property name="sessionFactory" ref="sessionFactory" /> 
    </bean> 
</beans> 

UserController

package org.vdzundza.web; 

import java.util.Map; 

import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.stereotype.Controller; 
import org.springframework.validation.BindingResult; 
import org.springframework.web.bind.annotation.ModelAttribute; 
import org.springframework.web.bind.annotation.RequestMapping; 
import org.springframework.web.bind.annotation.RequestMethod; 
import org.vdzundza.beans.User; 
import org.vdzundza.service.UserService; 

@Controller 
@RequestMapping("/user") 
public class UserController { 

    @Autowired 
    private UserService userService; 

    @RequestMapping("/") 
    public String index(){ 
     return "redirect:/user/index"; 
    } 

    @RequestMapping("/index") 
    public String listUsers(Map<String, Object> map){ 
     map.put("user", new User()); 
     map.put("userList", userService.listUser()); 
     return "user"; 
    } 

    @RequestMapping(value = "/add",method = RequestMethod.POST) 
    public String addUser(@ModelAttribute("user") User user, BindingResult result){ 
     userService.addUser(user); 
     return "redirect:/user/index"; 
    } 
} 

user.jsp

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> 
<%@ page language="java" contentType="text/html; charset=utf-8" 
    pageEncoding="utf-8"%> 
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%> 
<!DOCTYPE html> 
<html> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 
<title>user test spring and hibernate</title> 
</head> 
<body> 
    <a href="${pageContext.request.contextPath}/">Go back</a> 
    <br /> 

    <form:form method="post" 
     action="${pageContext.request.contextPath}/user/add" 
     commandName="user"> 
     <table> 
      <tr> 
       <td><form:label path="firstName">First Name</form:label></td> 
       <td><form:input path="firstName" /></td> 
      </tr> 

      <tr> 
       <td><form:label path="lastName">Last Name</form:label></td> 
       <td><form:input path="lastName" /></td> 
      </tr> 

      <tr> 
       <td><form:label path="network">network</form:label></td> 
       <td><form:input path="network" /></td> 
      </tr> 
      <tr> 
       <td colspan="2"><input type="submit" value="add user" /></td> 
      </tr> 

     </table> 
    </form:form> 


    <c:if test="${empty userList}"> 
     <h2>user list is empty</h2> 
    </c:if> 

    <c:if test="${!empty userList}"> 
     <h2>user list</h2> 
     <table> 
      <tr> 
       <th>First name</th> 
       <th>Last name</th> 
       <th>Network</th> 
      </tr> 

      <c:forEach items="${userList}" var="user"> 
       <tr> 
        <td>${user.firstName}</td> 
        <td>${user.lastName}</td> 
        <td>${user.network}</td> 
       </tr> 
      </c:forEach> 
     </table> 
    </c:if> 
</body> 
</html> 

Новый пользователь не сохраняется в базе данных. Когда я нажимаю «добавить пользователя» Я вижу это в консоли:

Hibernate: select nextval ('user_seq') 
Hibernate: select this_.id as id0_0_, this_.firstname as firstname0_0_, this_.hash as hash0_0_, this_.identity as identity0_0_, this_.isonline as isonline0_0_, this_.lastname as lastname0_0_, this_.network as network0_0_, this_.photo as photo0_0_ from users this_ 

Как исправить эту проблему?

Answer 1

После того, как вы откроете сеанс и сохраните объект ... запустите сеанс, затем закройте его.

Session session = sessionFactory.openSession(); 
session.save(user); 
session.flush(); 
session.close(); 

Answer 2

Получить Преимущество Hibernate Transaction:

В один transaction вы можете сделать несколько операций и может committransaction сразу же после успешного завершения всех операций. Преимущество здесь в том, что вы можете rollback все предыдущие операции, если одна операция завершилась неудачно в вашем operation batch.

Session session = factory.openSession(); 
    Transaction tx = null; 
    try { 
     tx = session.beginTransaction(); 


     session.save(user); 


     tx.commit(); // Flush happens automatically 
    } 
    catch (RuntimeException e) { 
     tx.rollback(); 
     throw e; // or display error message 
    } 
    finally { 
     session.close(); 
    }