javaweb请求转发——登录页面跳转

骑猪看日落 2022-03-21 10:25 391阅读 0赞

### 文章目录 ###

*   *   *   *  一、项目结构
             *  二、login.html
             *  三、ServletLogin.java
             *  四、loginError.jsp
             *  五、部署和运行
             *   *  1、测试用例一：（用户名错误）
                 *  2、测试用例二： （用户名正确，密码错误）

#### 一、项目结构 ####

![在这里插入图片描述][20190201014507894.]

#### 二、login.html ####

<!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>用户登录</title>
    </head>
    <body>
        <h3>用户登录</h3>
        <form action="login" method="get">
            <p>用户名<input type="text" name="username"></p>
            <p>密 码<input type="text" name="password"></p>
            <input type="submit" value="登录">
        </form>
    </body>
    </html>

#### 三、ServletLogin.java ####

package net.test.servlet;
    
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.IOException;
    
    @WebServlet(name = "ServletLogin",urlPatterns = "/login")
    public class ServletLogin extends HttpServlet {
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        }
    
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            //用户列表
            String user="user123";
            String pass="pass123";
            //获取客户端传来的参数
            String username = request.getParameter("username");
            String password = request.getParameter("password");
            if(!user.equals(username)){
                /*用户名不存在*/
                //request携带数据到web资源
                request.setAttribute("errorMessage","用户名不存在");
                //请求转发
                request.getRequestDispatcher("/loginError.jsp").forward(request,response);
            }else if(!pass.equals(password)){
                /*密码错误*/
                //request携带数据到web资源
                request.setAttribute("errorMessage","密码错误");
                //请求转发
                request.getRequestDispatcher("/loginError.jsp").forward(request,response);
            }
        }
    }

#### 四、loginError.jsp ####

<%--
      Created by IntelliJ IDEA.
      User: Administrator
      Date: 2019/2/1
      Time: 1:20
      To change this template use File | Settings | File Templates.
    --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>用户登录错误</title>
    </head>
    <body>
        <h3>用户登录错误界面</h3>
        <%=request.getAttribute("errorMessage")%>
    </body>
    </html>

#### 五、部署和运行 ####

访问login.html  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW_E7_94_A8_E6_88_B7_E5_90_8D_E9_94_99_E8_AF_AF5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hqdTIy_size_16_color_FFFFFF_t_70]

##### 1、测试用例一：（用户名错误） #####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hqdTIy_size_16_color_FFFFFF_t_70]  
跳转到用户登录错误界面，提示“用户名名不存在”  
![在这里插入图片描述][20190201015001716.]

##### 2、测试用例二： （用户名正确，密码错误） #####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hqdTIy_size_16_color_FFFFFF_t_70 1]  
跳转到用户登录错误界面，提示“密码错误”  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hqdTIy_size_16_color_FFFFFF_t_70 2]

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