登录系统-基于servlet+hibernate

 

 1.新建一个java web项目，在步骤4中选择Hibernate3.2.5选项（如果没有建好数据库连接，可以在此建立连接）：

 

 

这时netbeans自动生成hibernate.cfg.xml文件：

<?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.dialect">org.hibernate.dialect.MySQLDialect</property>

    <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>

    <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/book</property>

    <property name="hibernate.connection.username">root</property>

    <property name="hibernate.connection.password">123456</property>

  </session-factory>

</hibernate-configuration>

这个文件在系统中添加了连接数据库的驱动程序以及所连接的数据库、用户名和密码。

2. 使用Hibernate逆向工程向导生成hibernate.reveng.xml文件，如图所示添加选中的数据表。

 

 

 

自动生成的文件：hibernate.reveng.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-reverse-engineering PUBLIC "-//Hibernate/Hibernate Reverse Engineering DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-reverse-engineering-3.0.dtd " >

<hibernate-reverse-engineering>

  <schema-selection match-catalog="book"/>

  <table-filter match-name="admin"/>

</hibernate-reverse-engineering>

这个文件在系统中注册了数据库“book”和数据表“admin”。

3. 使用Hibernate向导生成Hibernate映射文件和POJO（Plain Ordinary Java Object）文件：

 

 


 
 

生成的POJO文件是：

 

Admin.java

package javahibernate;

// Generated 2011-11-19 10:57:36 by Hibernate Tools 3.2.1.GA

 

/**

 * Admin generated by hbm2java

 */

public class Admin  implements java.io.Serializable {

     private int UId;

     private String UName;

     private String UPass;

   

public Admin() {

    }

    public Admin(int UId) {

        this.UId = UId;

    }

    public Admin(int UId, String UName, String UPass) {

       this.UId = UId;

       this.UName = UName;

       this.UPass = UPass;

    }

  

    public int getUId() {

        return this.UId;

    }

   

    public void setUId(int UId) {

        this.UId = UId;

    }

    public String getUName() {

        return this.UName;

    }

   

    public void setUName(String UName) {

        this.UName = UName;

    }

    public String getUPass() {

        return this.UPass;

    }

   

    public void setUPass(String UPass) {

        this.UPass = UPass;

    }

}

生成的Hibernate映射文件是：

Admin.hbm.xml：

<?xml version="1.0"?>

<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<!-- Generated 2011-11-19 10:57:36 by Hibernate Tools 3.2.1.GA -->

<hibernate-mapping>

    <class name="javahibernate.Admin" table="admin" catalog="book">

        <id name="UId" type="int">

            <column name="u_id" />

            <generator class="assigned" />

        </id>

        <property name="UName" type="string">

            <column name="u_Name" length="20" />

        </property>

        <property name="UPass" type="string">

            <column name="u_Pass" length="20" />

        </property>

    </class>

</hibernate-mapping>

 

此时Hibernate配置文件hibernate.cfg.xml中，在<session-factory>标记内增加了映射信息：

<mapping resource="javahibernate/Admin.hbm.xml"/>

这两个文件构成了hibernate框架的核心基础：关系数据库到对象的映射，通过映射我们可以在项目中使用面向对象的编程技术。

到此为止，基于Hibernate的持久化工作已准备就绪。所有的工作基本上是自动完成的。

4.添加一个servlet类：LoginServlet，在步骤3中选中“将信息添加到部署描述符”选项。如图：

 

在LoginServlet.java文件加入如下代码：

package hibernate;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

 

import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.cfg.Configuration;

import org.hibernate.Criteria;

import org.hibernate.criterion.Expression;

import java.util.List;

 

public class LoginServlet extends HttpServlet {

 

    /**

     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.

     * @param request servlet request

     * @param response servlet response

     * @throws ServletException if a servlet-specific error occurs

     * @throws IOException if an I/O error occurs

     */

    protected void processRequest(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        response.setContentType("text/html;charset=UTF-8");

        // 获取提交的用户名：

       String UserName = request.getParameter("logname");

       // 获取提交的密码：

       String Password = request.getParameter("logpwd");         

 

              //核对用户名和密码，决定是否通过登陆验证

       Configuration cfg=new Configuration().configure();

        SessionFactory sessionFactory=cfg.buildSessionFactory();

        Admin user=new Admin();       

        Session session1=sessionFactory.openSession();

        Criteria criteria=session1.createCriteria(Admin.class);

        criteria.add(Expression.eq("UName",UserName));

        criteria.add(Expression.eq("UPass",Password));

        List list=criteria.list();       

        session1.close();

        sessionFactory.close();

       if (list.size()>=1) {

            // 登录成功时,把strUserName设成session变量UserName

            request.getSession(true).setAttribute("username", UserName);

            try {

                request.getRequestDispatcher("accesspage.jsp").forward(request,response);

            }catch (Throwable t) {

              getServletContext().log(t.getMessage());

            }

       } else {

            // 否则（记录集为空），表明失败：

            request.setAttribute("error", "用户名与密码不匹配,登录失败,请重试！");

            try {

              request.getRequestDispatcher("Login.jsp").forward(request, response);

            }

            catch (Throwable t) {

                getServletContext().log(t.getMessage());

            }

       }

   }

 

 

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">

    /**

     * Handles the HTTP <code>GET</code> method.

     * @param request servlet request

     * @param response servlet response

     * @throws ServletException if a servlet-specific error occurs

     * @throws IOException if an I/O error occurs

     */

    @Override

    protected void doGet(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        processRequest(request, response);

    }

 

    /**

     * Handles the HTTP <code>POST</code> method.

     * @param request servlet request

     * @param response servlet response

     * @throws ServletException if a servlet-specific error occurs

     * @throws IOException if an I/O error occurs

     */

    @Override

    protected void doPost(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        processRequest(request, response);

    }

 

    /**

     * Returns a short description of the servlet.

     * @return a String containing servlet description

     */

    @Override

    public String getServletInfo() {

        return "Short description";

    }// </editor-fold>

}

 

打开web.xml文件，可以看到如下关于servlet的部署设置：

<servlet>

        <servlet-name>LogServlet</servlet-name>

        <servlet-class>hibernate.LoginServlet</servlet-class>

    </servlet>

    <servlet-mapping>

        <servlet-name>LogServlet</servlet-name>

        <url-pattern>/LoginServlet</url-pattern>

    </servlet-mapping>

 

5.创建如下两个页面：

login.jsp

<%@ page pageEncoding="UTF-8" %>

<%@ page contentType="text/html; charset=gb2312" %>

<% request.setCharacterEncoding("gb2312"); %>

<%@ page language="java" %>

<html>  

         <head><title>登录网页</title></head>

       <body>

       <form method="POST" action="./LoginServlet">

 

       <table  >

           <tr>

             <td width="890" align="left" colspan="2">

              <b><font size="5">系统登录</font></b>

               <hr>

             </td>

           </tr>

            <% if (request.getAttribute("error") != null){ %>

       <tr>

              <td width=100% align=center colspan=4 height=36>

                   <font color=red><b><%=request.getAttribute("error")%></b></font>

              </td>

       </tr>

       <%

     }

       %>

           <tr>

             <td width="75" align="center">

               <p align="right">账号：</p>

             </td>

             <td width="809" align="center">

               <p align="left">

                <input type="text" name="logname" size="20"></td>

           </tr>

           <tr>

             <td width="75" align="center">

               <p align="right">密码：</p>

             </td>

             <td width="809" align="center">

               <p align="left">

               <input type="password" name="logpwd" size="20">

               <input type="submit" value="登录" name="loginButton"></td>

           </tr>

         </table>

       </form>

       </body>

       </html>

accesspage.jsp

<%@page contentType="text/html" pageEncoding="UTF-8"%>

<!DOCTYPE html>

<html>

    <head>

        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

        <title>登录成功</title>

    </head>

    <body>

        <h1>Hello

            <% if (request.getAttribute("username") != null){ %>       

              <font color=red>

                     <b>

                         <%=request.getAttribute("username")%>

                     </b>

                </font>  

            <%

                }

            %>

         !</h1>

    </body>

</html>

6.生成项目，并运行http://localhost:8080/login/login.jsp