SpringMVC----REST设计风格

1. 开发风格

是一种开发风格，遵从此风格开发软件，符号REST风格，则RESTFUL

两个核心要求

• 每个资源都有唯一的访问路径（访问标识）
• 不同的行为（增删改查），使用对应的请求方式（get、post、put、delete）

请求方式	标识	意图
GET	http://localhost:8080/xxx/users	查询所有用户
POST	http://localhost:8080/xxx/users	在所有用户中增加一个
PUT	http://localhost:8080/xxx/users	在所有用户中修改一个
DELETE	http://localhost:8080/xxx/users/1	删除用户1
GET	http://localhost:8080/xxx/users/1	查询用户1
GET	http://localhost:8080/xxx/users/1/orders	查询用户1的所有订单
POST	http://localhost:8080/xxx/users/1/orders	在用户1的所有订单中增加一个

以上，查询——GET、增加——POST、修改——PUT、

2. 优点

看url就知道要什么
看http method（请求方式）就知道干什么

3. 使用 3.1 环境搭建

1. 导入依赖：jackson、javax.servlet-api、jsp-api、jstl、spring-webmvc
   pom.xml如下：

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0modelVersion>

    <groupId>org.examplegroupId>
    <artifactId>springMVC07artifactId>
    <version>1.0-SNAPSHOTversion>
    <packaging>warpackaging>
    <dependencies>
        <dependency>
            <groupId>org.mybatisgroupId>
            <artifactId>mybatisartifactId>
            <version>3.4.6version>
        dependency>
        <dependency>
            <groupId>org.mybatisgroupId>
            <artifactId>mybatis-springartifactId>
            <version>1.3.1version>
        dependency>
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
            <version>5.1.47version>
        dependency>
        <dependency>
            <groupId>junitgroupId>
            <artifactId>junitartifactId>
            <version>4.12version>
            <scope>compilescope>
        dependency>
        <dependency>
            <groupId>log4jgroupId>
            <artifactId>log4jartifactId>
            <version>1.2.17version>
        dependency>
        <dependency>
            <groupId>javax.servletgroupId>
            <artifactId>javax.servlet-apiartifactId>
            <version>3.1.0version>
        dependency>
        <dependency>
            <groupId>javax.servletgroupId>
            <artifactId>jstlartifactId>
            <version>1.2version>
        dependency>
        <dependency>
            <groupId>javax.servletgroupId>
            <artifactId>jsp-apiartifactId>
            <version>2.0version>
        dependency>
        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>druidartifactId>
            <version>1.2.9version>
        dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.coregroupId>
            <artifactId>jackson-databindartifactId>
            <version>2.9.8version>
        dependency>
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-webmvcartifactId>
            <version>5.3.16version>
        dependency>
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-jdbcartifactId>
            <version>5.3.16version>
        dependency>
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-testartifactId>
            <version>5.1.6.RELEASEversion>
        dependency>
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-aspectsartifactId>
            <version>5.1.6.RELEASEversion>
        dependency>
    dependencies>
    <build>
        <resources>
            <resource>
                <directory>src/main/javadirectory>
                <includes>
                    <include>*.xmlinclude>
                    <include>**/*.xmlinclude>
                includes>
                <filtering>truefiltering>
            resource>
        resources>
    build>
project>

2. web.xml
   

<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <servlet>
        <servlet-name>mvc_xmqservlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
        <init-param>
            <param-name>contextConfigLocationparam-name>
            <param-value>classpath:mvc.xmlparam-value>
        init-param>
        <load-on-startup>1load-on-startup>
    servlet>
    <servlet-mapping>
        <servlet-name>mvc_xmqservlet-name>
        <url-pattern>/url-pattern>
    servlet-mapping>
web-app>

3. mvc.xml
   

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/mvc
                            http://www.springframework.org/schema/mvc/spring-mvc.xsd
                            http://www.springframework.org/schema/beans
                            http://www.springframework.org/schema/beans/spring-beans.xsd
                            http://www.springframework.org/schema/context
                            http://www.springframework.org/schema/context/spring-context.xsd"
>
    <context:component-scan base-package="com.lyx"/>
    <mvc:annotation-driven>mvc:annotation-driven>
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/">property>
        <property name="suffix" value=".jsp">property>
    bean>
    <mvc:default-servlet-handler>mvc:default-servlet-handler>
beans>

3.2 定义Rest风格的Controller

• 访问路径都一样，注解不同

package com.lyx.web;

import com.alibaba.druid.support.json.JSONUtils;
import com.lyx.entity.User;
import org.apache.ibatis.annotations.Param;
import org.springframework.web.bind.annotation.*;

import java.util.Arrays;
import java.util.Date;
import java.util.List;

@RestController
public class RESTController {
    @GetMapping("/users")
    public List<User> test(){
        System.out.println("你好啊");
        User user = new User(1, "lyx", "1233", 2, new Date());
        User user1 = new User(2, "xmq", "3434", 1, new Date());
        return Arrays.asList(user,user1);
    }
    @GetMapping("/users/{id}")
    public User test1(@PathVariable int id){
        User user = new User(id, "lll", "get1", 2, new Date());
        return user;
    }
    @PostMapping("/users")
    public String saveUser(@RequestBody String user){
//        User parse = (User)JSONUtils.parse(user);
//        System.out.println(parse);
        System.out.println(user);
        System.out.println("this is post");
        return "ok";
    }
    @PutMapping("/users")
    public String updateUsers(@RequestBody String user){
        System.out.println(user);
        System.out.println("this is put");
        return "ok";
    }
    @DeleteMapping("/users/{id}")
    public String deleteOne(@PathVariable int id){
        System.out.println(id);
        System.out.println("this is delete");
        return "ok";
    }
}

3.3 AJAX请求

• 访问路径一样，ajax的type=get（查）/post（增）/put（改）/delete（删）

<%--
  Created by IntelliJ IDEA.
  User: deqi5
  Date: 2022/5/9
  Time: 11:10
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Titletitle>
    <script src="static/js/jquery-3.5.1.js">script>
head>
<body>
<input type="button" value="hhh" onclick="hhh();">
<input type="button" value="query" onclick="query();">
<input type="button" value="saveUser" onclick="saveUser();">
<input type="button" value="updateUser" onclick="updateUser();">
<input type="button" value="deleteUser" onclick="deleteUser();">



<script>
    function hhh() {
        $.ajax({
            url:"${pageContext.request.contextPath}/users",
            type:"get",
            success:function (ret) {
                console.log(ret)
            }
        });
    }
    function query(){
        $.ajax({
            url:"${pageContext.request.contextPath}/users/1",
            type:"get",
            success:function (ret) {
                console.log(ret)
            }
        });
    }
    function saveUser() {
        var a = {id:3,username:"lyx",password:"34r34",gender:1,registTime:new Date()}
        $.ajax({
            url:"${pageContext.request.contextPath}/users",
            type:"post",
            data:JSON.stringify(a),
            contentType:"application/json",
            success:function (ret) {
                console.log(ret)
            }
        });
    }
    function updateUser() {
        var a = {id:1,username:"lyx",password:"34r34",gender:1,registTime:new Date()}
        $.ajax({
            url:"${pageContext.request.contextPath}/users",
            type:"put",
            data:JSON.stringify(a),
            contentType:"application/json",
            success:function (ret) {
                console.log(ret)
            }
        });
    }
    function deleteUser() {
        $.ajax({
            url:"${pageContext.request.contextPath}/users/1",
            type:"delete",
            success:function (ret) {
                console.log(ret)
            }
        });
    }
script>
body>
html>

3.4 Tomcat运行