@SessionTarget，休眠会话为空

Question

我正在使用 java、struts2、hibernate 构建一个简单的 MVC 应用程序。我创建了应用程序的结构使用瓷砖。我希望休眠创建表以继续我的下一个任务。 我相信，在将 JARS 导入我的应用程序及其正确版本时，我有一个误解。当我尝试插入数据时，hibernate 不会创建用户表并告诉我 session 为 null强>。

这是我的代码和导入的 jars。

谢谢！

hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>

        <property name="hibernate.connection.driver_class">com.mysql.cj.jdbc.Driver</property>
         <property name="hibernate.connection.url"> jdbc:mysql://localhost:3306/development</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">dothebest</property>
        <property name="connection.pool_size">1</property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="show_sql">true</property>
        <property name="hbm2ddl.auto">create</property>
        <!-- <mapping class="com.SchoolManagement.domain.Address" /> -->
        <mapping class="com.SchoolManagement.domain.User" />
    </session-factory>


</hibernate-configuration>

struts.xml

<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>

<package name="default" extends="hibernate-default,struts-default">

        <result-types>
            <result-type name="tiles" class="org.apache.struts2.views.tiles.TilesResult" />
        </result-types>

        <action name="home" method="home" class="com.SchoolManagement.action.BaseAction">
            <result name="success" type="tiles">home</result>
        </action>
        <action name="training" method="training" class="com.SchoolManagement.action.BaseAction">
            <result name="success" type="tiles">training</result>
        </action>
         <action name="contact" method="contact" class="com.SchoolManagement.action.BaseAction">
            <result name="success" type="tiles">contact</result>
        </action>
        <action name="listUser" method="list" class="com.SchoolManagement.action.UserAction">
            <result name="success" type="tiles">listmyUser</result>
        </action>
        <action name="saveOrUpdateUser" method="saveOrUpdate" class="com.SchoolManagement.action.UserAction">
            <result name="success" type="tiles">listmyUser</result>
        </action>

</package>

</struts>

UserAction.java

package com.SchoolManagement.action;

import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven;

import java.util.ArrayList;
import java.util.List;

import com.SchoolManagement.domain.User;
import com.SchoolManagement.service.UserService;
import com.SchoolManagement.service.UserServiceImpl;

public class UserAction extends ActionSupport implements ModelDriven<User>{

    private static final long serialVersionUID = -6659925652584240539L;

    private User user = new User();
    private List<User> userList = new ArrayList<User>();
    private UserService userService = new UserServiceImpl();



    @Override
    public User getModel() {
        return user;
    }
    /**
     * To save or update user.
     * @return String
     */
    public String saveOrUpdate()
    {   
        userService.saveOrUpdateUser(user);
        return SUCCESS;
    }

    public String list()
    {
        userList = userService.listUser();
        return SUCCESS;
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public List<User> getUserList() {
        return userList;
    }

    public void setUserList(List<User> userList) {
        this.userList = userList;
    }


}

UserServiceImpl.java

package com.SchoolManagement.service;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.Transaction;

import com.SchoolManagement.domain.User;
import com.googlecode.s2hibernate.struts2.plugin.annotations.SessionTarget;
import com.googlecode.s2hibernate.struts2.plugin.annotations.TransactionTarget;

public class UserServiceImpl implements UserService{

    @SessionTarget
    Session session;

    @TransactionTarget
    Transaction transaction;




    /**
     * Used to save or update a user.
     */
    @Override
    public void saveOrUpdateUser(User user) {
        try {
            session.saveOrUpdate(user);
        } catch (Exception e) {
            transaction.rollback();
            e.printStackTrace();
        }
    }

    /**
     * Used to list all the users.
     */

    @SuppressWarnings("unchecked")
    @Override
    public List<User> listUser() {

        // TODO Auto-generated method stub
        List<User> userList = null;
        System.out.println("1");
        try {
            System.out.println("2");    
            userList = session.createQuery("from User").list();
            System.out.println("3");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return userList;
    }

    }

listUser.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%@taglib uri="/struts-tags" prefix="s"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Registration Page</title>
<head>
</head>
<body>
<div class="page">

     <s:form action="saveOrUpdateUser">
        <s:push value="user">
            <s:hidden name="id" />
            <s:textfield name="name" label="User Name" />
            <s:textfield name="email" label="Email" />
            <s:submit />
        </s:push>
    </s:form> 


    <s:if test="userList.size() > 0">
        <div class="content">
        <table class="userTable" cellpadding="5px">
            <tr class="even">
                <th>Name</th>
                <th>Email</th>
                <th>Edit</th>
                <th>Delete</th>
            </tr>
            <s:iterator value="userList" status="userStatus">
                <tr
                    class="<s:if test="#userStatus.odd == true ">odd</s:if> <s:else>even</s:else>">
                    <td><s:property value="name" /></td>
                    <td><s:property value="email" /></td>
                    <td>
                    <s:url id="editURL" action="editUser">
                        <s:param name="id" value="%{id}"></s:param>
                    </s:url>
                    <s:a href="%{editURL}">Edit</s:a>
                    </td>
                    <td>
                    <s:url id="deleteURL" action="deleteUser">
                        <s:param name="id" value="%{id}"></s:param>
                    </s:url>
                    <s:a href="%{deleteURL}">Delete</s:a>
                    </td>
                </tr>
            </s:iterator>
        </table>
        </div>
    </s:if>
    </div>

    </body>
    </html>

这是我的罐子

这是错误：

Answer 1

对于hibernate核心Session和Transaction注入能力，我们需要使用basicStackHibernate拦截器。

所以将<interceptor-ref name="basicStackHibernate" /> 添加到您的操作中：

<action name="listUser" method="list" class="com.SchoolManagement.action.UserAction">
    <interceptor-ref name="basicStackHibernate" />
    <result name="success" type="tiles">listmyUser</result>
</action>