03-使用注解开发springmvc

使用注解开发springmvc

1.新建一个module，添加web的支持！

2.确定导入了springmvc的依赖

    <dependencies>

    <dependency>
        <groupId>junitgroupId>
        <artifactId>junitartifactId>
        <version>4.12version>

    dependency>
    <dependency>
        <groupId>org.springframeworkgroupId>
        <artifactId>spring-webmvcartifactId>
        <version>5.2.0.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>
    <build>
        <resources>
            <resource>
                <directory>src/main/javadirectory>
                <includes>
                    <include>**/*.propertiesinclude>
                    <include>**/*.xmlinclude>
                includes>
                <filtering>falsefiltering>
            resource>
            <resource>
                <directory>src/main/resourcesdirectory>
                <includes>
                    <include>**/*.propertiesinclude>
                    <include>**/*.xmlinclude>
                includes>
                <filtering>falsefiltering>
            resource>
        resources>
    build>

3.编写webxml

<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>

4.编写springmvc-servlet.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">


    <context:component-scan base-package="com.kuang.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>

简略版(去掉注释)springmvc-servlet.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">

    
    <context:component-scan base-package="com.kuang.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>

5.接下来就是去创建对应的控制类，controller

package com.kuang.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@Controller
@RequestMapping("/hello")  
//@RestController  加了就不会被视图解析器处理
public class HelloController{
    //访问路径相当于 localhost:8080/hello/h1
    @RequestMapping("/h1")
    public String hello(Model model){
        //封装数据
        model.addAttribute("msg","hello,SpringMVCAnnotation!");

        return "hello";//会被视图解析器处理

    }
}
/*
 @Controller是为了让Spring lOC容器初始化时自动扫描到;
 @RequestMapping是为了映射请求路径，这里因为类与方法上都有映射所以访问时应该是/HelloController/hello;
 方法中声明Model类型的参数是为了把Action中的数据带到视图中;
 方法返回的结果是视图的名称hello，加上配置文件中的前后缀变成WEB-INF/jsp/hello.jsp.
*/

6.完善前端视图和controller之间的对应 (也就是编写/WEB-INF/jsp下的hello.jsp)

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
${msg}
</body>
</html>

在视图解析器中我们把所有的视图都存放在/WEB-INF/目录下，这样可以保证视图安全，因为这个目录下的文件。客户端不能直接访问。

7.测试运行访问

使用springMVC必须配置的三大件:

处理器映射器、处理器适配器、视图解析器

通常，我们只需要手动配置视图解析器，而处理器映射器和处理器适配超只需要开启注解驱动即可，而省去了大段的xml配置