初识springmvc

狂神的servlet回顾就不在这里写了。可以翻之前的笔记。

原生开发：

创建webapp的maven项目。

也就是四个文件（不用思考里面的代码，直接CV先走一遍流程）

HelloController：


package com.Li.controller;
 
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
//注意：这里我们先导入Controller接口
public class HelloController implements Controller {
 
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
        //ModelAndView 模型和视图
        ModelAndView mv = new ModelAndView();
 
        //封装对象，放在ModelAndView中。Model
        mv.addObject("msg","HelloSpringMVC!");
 
        //封装要跳转的视图，放在ModelAndView中
        mv.setViewName("hello"); //: /WEB-INF/jsp/hello.jsp
 
        return mv;
    }
}

springmvc-servlet.xml：


"1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd">
 
    <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"/>
    <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"/>
 
    
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="InternalResourceViewResolver">
        
        <property name="prefix" value="/WEB-INF/jsp/"/>
        
        <property name="suffix" value=".jsp"/>
    bean>
 
    
    <bean id="/hello" class="com.Li.controller.HelloController"/>
 
 
 
beans>

hello.jsp：


<%--
  Created by IntelliJ IDEA.
  User: Li
  Date: 2022/12/1
  Time: 17:23
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Titletitle>
head>
<body>
${msg}
body>
html>

web.xml：


"1.0" encoding="UTF-8"?>
<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>springmvcservlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
        
        <init-param>
            <param-name>contextConfigLocationparam-name>
            <param-value>classpath:springmvc-servlet.xmlparam-value>
        init-param>
        
        <load-on-startup>1load-on-startup>
    servlet>
 
    
    
    <servlet-mapping>
        <servlet-name>springmvcservlet-name>
        <url-pattern>/url-pattern>
    servlet-mapping>
 
 
 
 
web-app>

pom.xml（外面那个）：


   <dependencies>
        <dependency>
            <groupId>junitgroupId>
            <artifactId>junitartifactId>
            <version>4.12version>
        dependency>
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-webmvcartifactId>
            <version>5.1.9.RELEASEversion>
        dependency>
        <dependency>
            <groupId>javax.servletgroupId>
            <artifactId>servlet-apiartifactId>
            <version>2.5version>
        dependency>
        <dependency>
            <groupId>javax.servlet.jspgroupId>
            <artifactId>jsp-apiartifactId>
            <version>2.2version>
        dependency>
        <dependency>
            <groupId>javax.servletgroupId>
            <artifactId>jstlartifactId>
            <version>1.2version>
        dependency>
    dependencies>

配置完tomcat之后直接run。之后路径上输入hello测试

404问题：

如果没有lib，添加一个lib文件夹。

选中lib点+号，之后点第一个

将这些全部导入，apply之后OK即可。

理解：

大致分为这三部分，对照视频理解每个文件级代码块的作用。

注解开发：

HelloController：


package com.Li.controller;
 
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
 
@Controller
//@RequestMapping("/hello")看第11行的注释，如果这行不注释的话，就是11行的效果
public class HelloController {
 
    //localhost:8080/hello/h1
    @RequestMapping("/h1")
    public String hello(Model model){
        //封装数据，向模型中添加值，可以在JSP页面取出并渲染
        model.addAttribute("msg", "Hello,SpringMVCAnnotation");
 
        return "hello";//会被视图解析器处理
    }
 
}

springmvc-servlet.xml：


"1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       https://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/mvc
       https://www.springframework.org/schema/mvc/spring-mvc.xsd">
 
    
    <context:component-scan base-package="com.Li.controller"/>
    
    <mvc:default-servlet-handler />
    
    <mvc:annotation-driven />
 
    
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
          id="internalResourceViewResolver">
        
        <property name="prefix" value="/WEB-INF/jsp/" />
        
        <property name="suffix" value=".jsp" />
    bean>
 
beans>

hello.jsp：


<%--
  Created by IntelliJ IDEA.
  User: Li
  Date: 2022/12/2
  Time: 22:55
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Titletitle>
head>
<body>
${msg}
body>
html>

web.xml：


"1.0" encoding="UTF-8"?>
<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>SpringMVCservlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
        
        <init-param>
            <param-name>contextConfigLocationparam-name>
            <param-value>classpath:springmvc-servlet.xmlparam-value>
        init-param>
        
        <load-on-startup>1load-on-startup>
    servlet>
 
    
    <servlet-mapping>
        <servlet-name>SpringMVCservlet-name>
        <url-pattern>/url-pattern>
    servlet-mapping>
 
web-app>

测试：

重点在于理解，代码都很简单。

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原文地址：https://blog.csdn.net/m0_54842832/article/details/128135803