JSP和Servlet（不同用户权限修改信息）

最新推荐文章于 2023-06-02 16:11:21 发布

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#servlet #jsp #javabean

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本文介绍了一个简单的Java Web权限管理系统案例，包括用户登录验证、不同权限级别的处理流程、使用session保存用户信息以及页面跳转等内容。

1、程序的结构流程图：
这里写图片描述
1、User.jsp(javabean)

package com.javabean;

public class User {
    private String username;
    private String password;
    private String quanxian;
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getQuanxian() {
        return quanxian;
    }
    public void setQuanxian(String quanxian) {
        this.quanxian = quanxian;
    }


}

2、UserAdmin.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">

    <title>My JSP 'MyJsp.jsp' starting page</title>

    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->

  </head>

  <!-- 重点在下面的三元表达式 -->
    <body>
        <%String value = (String)request.getAttribute("quanxian"); %>
    <form action="UserAdminServlet" method = "post">
        username :<input type = "text" name = "username" value = "<%= (null == request.getAttribute("username"))? "" : request.getAttribute("username") %>"><br>
        password :<input type = "password" name = "password"><br>
        权限：<select name = "quanxian">
        <!-- 获取的权限值收费符合 否则为空 -->
                <option value = "commom" <%= "commom".equals(value) ? "selected" : "" %>>普通用户</option>
                <option value = "admin" <%= "admin".equals(value) ? "selected" : "" %>>管理员</option>
        </select><br>
        <input type = "submit" value = "提交">
    </form>

  </body>
</html>
<%--
//下面是重定向传来获得参数对比
<form action="UserAdminServlet2" method = "post">
        username :<input type = "text" name = "username" value = "<%= (null ==  request.getParameter("username"))? "" : request.getParameter("username") %>"><br>
        password :<input type = "password" name = "password"><br>
        权限：<select name = "quanxian">
                <option value = "commom" <%= "commom".equals(request.getParameter("quanxian")) ? "selected" : "" %>>普通用户</option>
                <option value = "admin" <%= "admin".equals(request.getParameter("quanxian")) ? "selected" : "" %>>管理员</option>
        </select><br>
        <input type = "submit" value = "提交">
    </form>

--%>

这里写图片描述
3、UserAdminServlet

package com.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.javabean.User;

public class UserAdminServlet extends HttpServlet {

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String quanxian = request.getParameter("quanxian");

        //是否为普通用户？session/UserAdminSuccess.jsp ：session/UserAdmin.jsp； 
        if ("commom".equals(quanxian)) {
            if ("commom".equals(username) && "commom".equals(password)) {
                User user = new User();
                user.setUsername(username);
                user.setPassword(password);
                user.setQuanxian(quanxian);
                HttpSession session = request.getSession();
                session.setAttribute("user", user);

                request.getRequestDispatcher("session/UserAdminSuccess.jsp").forward(
                        request, response);
            } else {
                request.setAttribute("username", username);
                request.setAttribute("quanxian", quanxian);
                //下面重定向是通过地址栏的方式传递参数
                //response.sendRedirect("UserAdmin2.jsp?username="+username+"&quanxian="+quanxian+"");


                request.getRequestDispatcher("session/UserAdmin.jsp").forward(request,
                        response);
            }
            //是否为admin用户 ？ session/UserAdminSuccess.jsp ：session/UserAdmin.jsp； 
        } else if ("admin".equals(quanxian)) {
            if ("admin".equals(username) && "admin".equals(password)) {
                User user = new User();
                user.setUsername(username);
                user.setPassword(password);
                user.setQuanxian(quanxian);
                HttpSession session = request.getSession();
                session.setAttribute("user", user);

                //下面重定向是通过地址栏的方式传递参数
                //response.sendRedirect("UserAdmin2.jsp?username="+username+"&quanxian="+quanxian+"");

                request.getRequestDispatcher("session/UserAdminSuccess.jsp").forward(
                        request, response);
            } else {
                request.setAttribute("username", username);
                request.setAttribute("quanxian", quanxian);
                request.getRequestDispatcher("session/UserAdmin.jsp").forward(request,
                        response);
            }
        } else if ("".equals(username) || "".equals(password)) {
            //下面重定向是通过地址栏的方式传递参数
            //response.sendRedirect("UserAdmin2.jsp?username="+username+"&quanxian="+quanxian+"");
            request.getRequestDispatcher("session/UserAdmin.jsp").forward(request,
                    response);
        }
    }
}

/*


public class UserAdminServlet2 extends HttpServlet {

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String quanxian = request.getParameter("quanxian");

        if ("commom".equals(quanxian)) {
            if ("commom".equals(username) && "commom".equals(password)) {
                User user = new User();
                user.setUsername(username);
                user.setPassword(password);
                user.setQuanxian(quanxian);
                HttpSession session = request.getSession();
                session.setAttribute("commom", user);
                request.getRequestDispatcher("UserAdminSuccess.jsp").forward(
                        request, response);
            } else {

                response.sendRedirect("UserAdmin2.jsp?username="+username+"&quanxian="+quanxian+"");

//              request.setAttribute("username", username);
//              request.setAttribute("quanxian", quanxian);
//
//              request.getRequestDispatcher("UserAdmin.jsp").forward(request,
//                      response);
            }
        } else if ("admin".equals(quanxian)) {
            if ("admin".equals(username) && "admin".equals(password)) {
                User user = new User();
                user.setUsername(username);
                user.setPassword(password);
                user.setQuanxian(quanxian);
                HttpSession session = request.getSession();
                session.setAttribute("commom", user);
                request.getRequestDispatcher("UserAdminSuccess.jsp").forward(
                        request, response);
            } else {

                response.sendRedirect("UserAdmin2.jsp?username="+username+"&quanxian="+quanxian+"");
//              request.setAttribute("username", username);
//              request.setAttribute("quanxian", quanxian);
//              request.getRequestDispatcher("UserAdmin.jsp").forward(request,
//                      response);
            }
        } else if ("".equals(username) || "".equals(password)) {


            response.sendRedirect("UserAdmin2.jsp?username="+username+"&quanxian="+quanxian+"");
//          request.getRequestDispatcher("UserAdmin.jsp").forward(request,
//                  response);
        }
    }
}

 * 
 * 
 */

4、UserAdminSuccess.jsp

 <body>
        <% 
        User user = (User)session.getAttribute("user");
        if(null == user){
            response.sendRedirect("/Day08/session/UserAdmin.jsp");
            return;
        }
        %>
        <a href = "QueryServlet">Query</a><br>
        <!-- 做个判断是否显示Update -->
        <% 
            if(((User)session.getAttribute("user")).getQuanxian().equals("admin")){
        %>
        <a href = "UpdataServlet">Updata</a><br>
        <% } %>



  </body>

这里写图片描述
5、UpdataServlet

package com.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.javabean.User;

public class UpdataServlet extends HttpServlet {


    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        HttpSession session = req.getSession();
//      获取user的权限是否是admin？
        if(null == session.getAttribute("user") || !(((User)session.getAttribute("user")).getQuanxian()).equals("admin")){
            System.out.println("失败");
        }else{
            req.getRequestDispatcher("session/Updata.jsp").forward(req, resp);
            System.out.println("成功");
        }
    }

}

6、UpData.jsp

<body>
  <%
  User user = (User)session.getAttribute("user");
  %>
  <p>以前的session中的信息为：</p><br>
  username = <%= user.getUsername() %><br>
  password = <%= user.getPassword() %><br>
    权限：<%= user.getQuanxian() %><br>
    <p>请输入修改的信息：</p><br>
    <form action="UpDataControl">
    username : <input type = "text" name = "upDataUserName"><br>
    password : <input type = "password" name = "upDataPassword"><br>
    <input type = "submit" value = "更新数据"> 
    </form>


  </body>

这里写图片描述
7、UPdataControl

package com.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.javabean.User;

public class UpDataControl extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        User upDataUser = new User();
        upDataUser.setUsername(req.getParameter("upDataUserName"));
        upDataUser.setPassword(req.getParameter("upDataPassword"));

        HttpSession session = req.getSession();
        session.setAttribute("user", upDataUser);

        req.getRequestDispatcher("session/UpDataMessage.jsp").forward(req, resp);
    }

}

8、UpdataMessage.jsp

<body>
<%
  User user = (User)session.getAttribute("user");
  %>
  <p>现在的session中的信息为：</p><br>
  username = <%= user.getUsername() %><br>
  password = <%= user.getPassword() %><br>
  </body>