SpringMVC第一章

SpringMVC第一章

@autor:韩克 2019-07-24 10:42:05

springMVC工作原理

yuanli.png

注：
DispatcherServlet : 前置控制器,接收所有请求(如果配置/不包含 javap)
HandlerMapping: 解析请求格式的.判断希望要执行哪个具体的方法.
HandlerAdapter: 负责调用具体的方法.
ViewResovler:视图解析器.解析结果,准备跳转到具体的物理视图

环境搭建

1. 导入 jar
   

   1.jpg

2. 在 web.xml 中配置Spring配置文件和Web监听器

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                       http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classPath:applicationContext.xml</param-value>
    </context-param>
</web-app>

3. 在 web.xml 中配置前端控制器DispatcherServlet

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                       http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
                       
    <servlet>
        <servlet-name>springMVC</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>springMVC</servlet-name>
        <url-pattern>*.form</url-pattern>
    </servlet-mapping>

</web-app>

注意：
1.<url-pattern>*.form</url-pattern>中的*.form对应的是
  <form action="survey/2019.07.24/item.form" method="post">
2.<servlet-name>springMVC</servlet-name>决定了创建*-selvlet.xml文件名中的*
  即最后创建的springMVC配置文件的名字为springMVC-selvlet.xml

4. 在 WEB-INF 中创建*-selvlet.xml文件

    <?xml version="1.0" encoding="UTF-8"?>
    <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/context
    http://www.springframework.org/schema/context/spring-context.xsd
    http://www.springframework.org/schema/mvc
    http://www.springframework.org/schema/mvc/spring-mvc.xsd">
    <!-- 扫描注解 -->
    <context:component-scan base-package="com.xt.handler"/>
    </beans>

注意配置： <context:component-scan base-package="com.xt.handler"/> 这样才能将handler注册到DispatcherServlet中

5. 字符编码过滤器

<!-- 在 web.xml 中配置 Filter -->
<filter>
    <filter-name>encoding</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
        <param-name>encoding</param-name>
        <param-value>utf-8</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>encoding</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

6. 编写控制器类

使用@RequestParam 接受简单参数

@RequestMapping(value="/{week}/item",method=RequestMethod.POST)
    public String getParam(@PathVariable("week") String week,
            @RequestParam("name") String name,
            @RequestParam("age") int age,
            @RequestParam("tel") String tel,
            @RequestParam("answer1") String a1,
            @RequestParam("answer2") String a2,
            @RequestParam("answer3") String a3) {
        
        System.out.println(week+"  "+"调查问卷");
        System.out.println("姓名:"+name);
        System.out.println("年龄:"+"  "+age);
        System.out.println("tel:"+"  "+tel);
        System.out.println("对本期的封面和内容版式设计:"+"  "+a1);
        System.out.println("喜欢的文章:"+"  "+a2);
        System.out.println("不喜欢的文章:"+"  "+a3);
        return "redirect:/survey.javap";
        
    }

使用@ModelAttribute 接受一组数据，并封装成对象，并把该对象存储到request作用域中

@ModelAttribute("survey")Survey survey

@RequestMapping(value="/{week}/item",method=RequestMethod.POST)
    public String getParam2(@PathVariable("week")String week , @ModelAttribute("survey")Survey survey) {
        survey.setWeek(week);
        System.out.println(survey.getWeek()+"  "+"调查问卷");
        System.out.println("姓名:"+survey.getName());
        System.out.println("年龄:"+"  "+survey.getAge());
        System.out.println("tel:"+"  "+survey.getTel());
        System.out.println("对本期的封面和内容版式设计:"+"  "+survey.getAnswer1());
        System.out.println("喜欢的文章:"+"  "+survey.getAnswer2());
        System.out.println("不喜欢的文章:"+"  "+survey.getAnswer3());
        return "redirect:/survey.javap";        
    }

使用@PathVariable接受请求路径中的参数

@RequestMapping(value="/{week}/item",method=RequestMethod.POST)
@PathVariable("week")String week