JSP向Servlet传递数据以及与STM32、ESP8266通信过程

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这是一个Servlet类，采用此方法比较方便，因为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响应get请求，doPost响应post请求，为了保证不管在login.jsp中选择post方法还是get方法，在这里都能有所回应，所以

    //这里只在doPost中写相应的代码，而在doGet中直接调用doPost函数即可

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

//从login页面中获取用户名和密码

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("账号/密码不能为空");

return;

}else {

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

RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/ControlTest.jsp");//这句话的意思是当验证账号密码都正确后，要继续跳转到哪一个页面，这里是跳转到ControlTest页面

dispatcher.forward(request, response);

SocketTest.getSocket();//这句话是用来创建一个服务器等待客户端(连接在STM32上的8266)的连接，连接成功后生成一个Socket用来双方的通信。注意创建Socket以及等待客户端连接一定要在页面跳转到控制页面之后进行，因为等待客户端连接是一个阻塞函数，程序会一直死在那里等待客户端的连接

}else {

//response.sendRedirect("login.jsp");//直接重定向到登录页面，无任何提示信息

//有登录失败的提示信息，但是跳到了一个新页面，点击确定之后重新回到登录页面回到指定页面

PrintWriter out = response.getWriter();

out.print("");

}

}

}

}

ControlTest.jsp

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

    pageEncoding="utf-8"%>

这里是控制系统

控制按钮