SpringMVC第一天

简介

SpringMVC技术与Servlet技术功能等同，均属于web层开发技术

SpringMVC是一种基于java实现的MVC模型的轻量级Web框架

优点

使用简单,开发便捷(相比于Servlet)

灵活性强

入门案例

第一步、导入SpringMVC与Servlet坐标

<?xml version="1.0" encoding="UTF-8"?>

<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>4.0.0</modelVersion>

  <groupId>com.cacb</groupId>
  <artifactId>SpringMVC_demo1</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>



  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.1.0</version>
      <scope>provided</scope>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>5.2.10.RELEASE</version>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.tomcat.maven</groupId>
        <artifactId>tomcat7-maven-plugin</artifactId>
        <version>2.1</version>
        <configuration>
          <port>80</port>
          <path>/</path>
        </configuration>
      </plugin>
    </plugins>
  </build>

</project>

第二步、创建SpringMVC控制类(等同于Servlet功能)

package com.cacb.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

//定义controller（使用@Controller定义Bean）
@Controller
public class UserController {
    //设置当前操作的返回路径
    @RequestMapping("/save")
    
//设置当前路径的返回值类型
    @ResponseBody
    public String save(){
        System.out.println("user saving!");
        return "{'module':'SpringMVC'}";
    }
}

第三步、初始化SpringMVC环境(同SPring环境)，设定SpringMVC加载对应的Bean

package com.cacb.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
//创建spring配置文件，加载controller对应的bean
@Configuration
@ComponentScan("com.cacb.controller")
public class SpringMVCConfig {
}

第四步、初始化Servlet容器，加载SPringMVC环境，并设置SpringMVC技术处理的请求

package com.cacb.config;

import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
import org.springframework.web.servlet.support.AbstractDispatcherServletInitializer;

//定义一个servlet容器启动的配置类，在里面加载spring配置
public class ServletContainersInitConfig extends AbstractDispatcherServletInitializer {
    // 加载springMVC容器配置
    @Override
    protected WebApplicationContext createServletApplicationContext() {
        AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();
        ctx.register(SpringMVCConfig.class);
        return ctx;
    }
    //设置哪些请求归属springMVC处理
    @Override
    protected String[] getServletMappings() {
        //所有请求归springmvc管理
        return new String[]{"/"};
    }
    //加载spring容器配置
    @Override
    protected WebApplicationContext createRootApplicationContext() {
        return null;
    }
}