文章目录
一、项目结构
login.html用户信息错误，进行请求转发，跳转到loginError.html。
用户信息正确，进行重定向，跳转到home.html。
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);
}else{
//必须加项目地址，这里加hello
response.sendRedirect("/hello/home.html");
}
}
}
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、home.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>首页</title>
</head>
<body>
<h3>网站首页</h3>
</body>
</html>
六、部署和运行
部署项目
访问login.html
1、测试用例一（用户名错误）
跳转到用户登录错误页面，提示“用户名不存在”
2、测试用例二（密码错误）
跳转到用户登录错误页面，提示“密码错误”
3、测试用例二（账号信息正确）
跳转到网站首页