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1. HTTP协议

网址：https://www.ietf.org/ （官网网址）
https://developer.mozilla.org/zh-CN/ （易于理解）

HyperText Transfer Potocal
用于传输HTML等内容的应用层协议
规定了浏览器和服务器之间如何通信，以及通信时的数据格式

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2. Spring MVC

2.1. 三层架构

表现层、业务层、数据访问层

2.2. MVC（解决表现层的问题）

Model： 模型层
View： 视图层
Controller：控制层

2.3. 核心组件

前端控制器：DispatcherServlet

3. Thymeleaf

网址：http://thymeleaf.org/

3.1. 模板引擎

生成动态的HTML

3.2. Thymeleaf

倡导自然模板，即以HTML文件为模板

3.3. 常用语法

标准表达式、判断与循环、模板的布局

代码

package com.test.community.controller;import com.test.community.service.AlphaService;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;import java.io.IOException;
import java.io.PrintWriter;
import java.util.*;/*** @ClassName AlphaController* @Description TODO* @Author lcx* @Date 2024/2/21 15:22* @Version 1.0*/
@Controller
@RequestMapping("/alpha")
public class AlphaController {@Autowiredprivate AlphaService alphaService;@RequestMapping("/hello")@ResponseBodypublic String sayHello() {return "Hello Spring Boot!";}@RequestMapping("/data")@ResponseBodypublic String getData() {return alphaService.find();}// SpringMVC获得请求对象和响应对象@RequestMapping("/http")public void http(HttpServletRequest request, HttpServletResponse response) {// 获取请求数据System.out.println(request.getMethod());System.out.println(request.getServletPath());Enumeration<String> enumeration = request.getHeaderNames();while (enumeration.hasMoreElements()) {String name = enumeration.nextElement();String value = request.getHeader(name);System.out.println(name + ":" + value);}// 请求体System.out.println(request.getParameter("code"));// 返回响应数据response.setContentType("text/html; charset=utf-8");try(PrintWriter writer = response.getWriter();) {writer.write("<h1>牛客网</h1>");} catch (IOException e) {e.printStackTrace();}}// GET请求// 查询所有学生  /students?current=1&limit=20@RequestMapping(path = "/students", method = RequestMethod.GET)@ResponseBodypublic String getStudents(@RequestParam(name = "current", required = false, defaultValue = "1") int current,@RequestParam(name = "limit", required = false, defaultValue = "10") int limit) {System.out.println(current);System.out.println(limit);return "some students";}// /student/123@RequestMapping(path = "/student/{id}", method = RequestMethod.GET)@ResponseBodypublic String getStudent(@PathVariable("id") int id) {System.out.println(id);return "a student";}// 浏览器向服务器提交数据// POST请求@RequestMapping(path = "/student", method = RequestMethod.POST)@ResponseBodypublic String saveStudent(String name, int age) {System.out.println(name);System.out.println(age);return "success";}// 响应HTML数据@RequestMapping(path = "/teacher", method = RequestMethod.GET)@ResponseBodypublic ModelAndView getTeacher() {ModelAndView mav = new ModelAndView();mav.addObject("name", "张三");mav.addObject("age", 12);mav.setViewName("/demo/view");return mav;}@RequestMapping(path = "/school", method = RequestMethod.GET)public String getSchool(Model model) {model.addAttribute("name", "北京大学");model.addAttribute("age", 123);return "/demo/view";}// 异步请求中响应JSON数据// java对象 -> JSON字符串 -> JS对象@RequestMapping(path = "/emp", method = RequestMethod.GET)@ResponseBodypublic Map<String, Object> getEmp() {Map<String, Object> emp = new HashMap<>();emp.put("name", "张三");emp.put("age", 12);emp.put("salary", 8000.00);return emp;}@RequestMapping(path = "/emps", method = RequestMethod.GET)@ResponseBodypublic List<Map<String, Object>> getEmps() {List<Map<String, Object>> list = new ArrayList<>();Map<String, Object> emp = new HashMap<>();emp.put("name", "张三");emp.put("age", 12);emp.put("salary", 8000.00);list.add(emp);emp = new HashMap<>();emp.put("name", "李四");emp.put("age", 22);emp.put("salary", 9000.00);list.add(emp);emp = new HashMap<>();emp.put("name", "王五");emp.put("age", 32);emp.put("salary", 10000.00);list.add(emp);return list;}}

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