ValidateTest.java

package servlet;

import java.io.IOException;

import java.io.PrintWriter;

import javax.servlet.RequestDispatcher;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

/**

 * Servlet implementation class LoginServlet

 */

//@WebServlet是采用注入的方式表示這是一個Servlet類，采用此方法比較方便，因為此方法不用再去配置web.xml文件

@WebServlet("/ValidateTest")

public class ValidateTest extends HttpServlet {

private static final long serialVersionUID = 1L;

    /**

     * @see HttpServlet#HttpServlet()

     */

    public ValidateTest() {

        super();

        // TODO Auto-generated constructor stub

    }

/**

* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)

*/

    //doGet響應get請求，doPost響應post請求，為了保證不管在login.jsp中選擇post方法還是get方法，在這里都能有所回應，所以

    //這里只在doPost中寫相應的代碼，而在doGet中直接調用doPost函數即可

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

doPost(request, response);

// response.getWriter().append(info);

}

private void alert(String string) {

// TODO Auto-generated method stub

}

/**

* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)

*/

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

// TODO Auto-generated method stub

//從login頁面中獲取用戶名和密碼

String name = request.getParameter("Username");

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

response.setCharacterEncoding("utf-8");

response.setContentType("text/html");

if(name == null || password == null || name.equals("") || password.equals("")) {

response.getWriter().append("賬號/密碼不能為空");

return;

}else {

if(name.equals("asddssdf") && password.equals("sdjfhjhffjshbfgk")) {

RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/ControlTest.jsp");//這句話的意思是當驗證賬號密碼都正確后，要繼續跳轉到哪一個頁面，這里是跳轉到ControlTest頁面

dispatcher.forward(request, response);

SocketTest.getSocket();//這句話是用來創建一個服務器等待客戶端(連接在STM32上的8266)的連接，連接成功后生成一個Socket用來雙方的通信。注意創建Socket以及等待客戶端連接一定要在頁面跳轉到控制頁面之后進行，因為等待客戶端連接是一個阻塞函數，程序會一直死在那里等待客戶端的連接

}else {

//response.sendRedirect("login.jsp");//直接重定向到登錄頁面，無任何提示信息

//有登錄失敗的提示信息，但是跳到了一個新頁面，點擊確定之后重新回到登錄頁面回到指定頁面

PrintWriter out = response.getWriter();

out.print("");

}

}

}

}

ControlTest.jsp

<%@ page language="java" contentType="text/html; charset=utf-8"

    pageEncoding="utf-8"%>

這里是控制系統

控制按鈕