javawebServlet体系结构

HttpServlet

 具体书写格式

@WebServlet("/demo4")
public class ServletDemo4 extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//TODO GET 请求方式处理逻辑System.out.println("get...");}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//TODO Post 请求方式处理逻辑System.out.println("post...");}
}


Servlet urlPattern配置

Request和Response

简介

Request

Request继承体系

Request获取请求数据

Request统一方式获取请求参数

获取GET方式的所有请求参数

/*** request 通用方式获取请求参数*/
@WebServlet("/req2")
public class RequestDemo2 extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//GET请求逻辑System.out.println("get....");//1. 获取所有参数的Map集合Map map = req.getParameterMap();for (String key : map.keySet()) {// username:zhangsan lisiSystem.out.print(key+":");//获取值String[] values = map.get(key);for (String value : values) {System.out.print(value + " ");}System.out.println();}}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {this.doGet(req,resp)}
}


获取GET请求参数中的爱好，结果是数组值

/*** request 通用方式获取请求参数*/
@WebServlet("/req2")
public class RequestDemo2 extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//GET请求逻辑//...System.out.println("------------");String[] hobbies = req.getParameterValues("hobby");for (String hobby : hobbies) {System.out.println(hobby);}}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {}
}

获取GET请求参数中的用户名和密码，结果是单个值

/*** request 通用方式获取请求参数*/
@WebServlet("/req2")
public class RequestDemo2 extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//GET请求逻辑//...String username = req.getParameter("username");String password = req.getParameter("password");System.out.println(username);System.out.println(password);}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {}
}

Request共享数据

Response

Response设置响应数据功能介绍

Response完成重定向

 (1)创建ResponseDemo1类

@WebServlet("/resp1")
public class ResponseDemo1 extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {System.out.println("resp1....");//重定向//1.设置响应状态码 302response.setStatus(302);//2. 设置响应头 Locationresponse.setHeader("Location","/request-demo/resp2");}//简化写法response.SendRedirect("request-demo/resp2");@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doGet(request, response);}
}

(2)创建ResponseDemo2类

@WebServlet("/resp2")
public class ResponseDemo2 extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {System.out.println("resp2....");}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doGet(request, response);}
}