Servlet 获取网页信息（request的应用）首先，如何设置web启动时的页面在web.xml中login.jsp

首先，如何设置web启动时的页面

在web.xml中

<welcome-file-list>
    <welcome-file>login.jsp</welcome-file>
 </welcome-file-list>

login.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
   <title>Title</title>
</head>
<body>
     <form action="${pageContext.request.contextPath}/login" method="post">
         用户名：<input type="text" name="na"><br>
         密码： <input type="password" name="passwd"><br>
         爱好：<br>
         <input type="checkbox" name="hobby" value="篮球">篮球<br>
         <input type="checkbox" name="hobby" value="足球">足球<br>
         <input type="checkbox" name="hobby" value="羽毛球">羽毛球<br>
         <input type="checkbox" name="hobby" value="乒乓球">乒乓球<br>
         <input type="submit">
     </form>
</body>
</html>

注意： action="${pageContext.request.contextPath}/login"

public class login extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("UTF8");
        resp.setCharacterEncoding("UTF8");
        String username = req.getParameter("na");
        String password = req.getParameter("passwd");
        String[] arr = req.getParameterValues("hobby");
        System.out.println("====================");
        System.out.println(username);
        System.out.println(password);
        System.out.println(Arrays.toString(arr));
        System.out.println("====================");
        resp.sendRedirect("success.html");
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}