spring mvc 起步
1：mvc的核心思想是业务数据抽取同业务数据呈现相分离
2：HandlerAdapter用来处理handleinterceptor和 ControlInter 生成的handleExecuteChain
请求 diapatcherServlet 接受请求，--> 交给handleMapper处理，返回一个 handleExecuteChain(包含拦截器和相应的handle) -->先执行注册的拦截器，在交给HandleAdapt 执行相应的handl,返回一个modleAndView.
3：mode ModelAndView map
4:为了防止用Maven管理Spring项目时，不同的项目依赖了不同版本的Spring，可以使用Maven BOM来解决者一问题。
在依赖管理时，引入spring-framework-bom，如：
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-framework-bom</artifactId>
<version>4.3.1.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
即可统一版本，而且，在引入BOM之后，在引入其他Spring依赖时，都无需指定版本，如：
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
</dependency>
<dependencies>
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<display-name>Spring MVC Study</display-name>
<!-- Spring应用上下文， 理解层次化的ApplicationContext -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/configs/spring/applicationContext*.xml</param-value>
</context-param>
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
</listener-class>
</listener>
<!-- DispatcherServlet, Spring MVC的核心 --> 可有有多个DispatcherServlet
<servlet>
<servlet-name>mvc-dispatcher</servlet-name>
<servlet-class> org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- DispatcherServlet对应的上下文配置， 默认为/WEB-INF/$servlet-name$-servlet.xml
-->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/configs/spring/mvc-dispatcher-servlet.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>mvc-dispatcher</servlet-name>
<!-- mvc-dispatcher拦截所有的请求-->
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
applicationContext.xml如下：
<?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: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
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<context:annotation-config />
<context:component-scan base-package="com.imooc.mvcdemo">
<context:exclude-filter type="annotation"
expression="org.springframework.stereotype.Controller" />
</context:component-scan>
</beans>
mvc-dispatcher-servlet.xml如下：
<?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: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
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!-- 本配置文件是工名为mvc-dispatcher的DispatcherServlet使用， 提供其相关的Spring MVC配置 -->
<!-- 启用Spring基于annotation的DI, 使用户可以在Spring MVC中使用Spring的强大功能。 激活 @Required
@Autowired,JSR 250's @PostConstruct, @PreDestroy and @Resource 等标注 -->
<context:annotation-config />
<!-- DispatcherServlet上下文， 只管理@Controller类型的bean， 忽略其他型的bean, 如@Service -->
<context:component-scan base-package="com.imooc.mvcdemo">
<context:include-filter type="annotation"
expression="org.springframework.stereotype.Controller" />
</context:component-scan>
<!-- HandlerMapping, 无需配置， Spring MVC可以默认启动。 DefaultAnnotationHandlerMapping
annotation-driven HandlerMapping -->
<!-- 扩充了注解驱动，可以将请求参数绑定到控制器参数 -->
<mvc:annotation-driven />
<!-- 静态资源处理， css， js， imgs -->
<mvc:resources mapping="/resources/**" location="/resources/" />
<!-- 配置ViewResolver。 可以用多个ViewResolver。 使用order属性排序。 InternalResourceViewResolver放在最后。 -->
<bean
class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
<property name="order" value="1" />
<property name="mediaTypes">
<map>
<entry key="json" value="application/json" />
<entry key="xml" value="application/xml" />
<entry key="htm" value="text/html" />
</map>
</property>
<property name="defaultViews">
<list>
<!-- JSON View -->
<bean
class="org.springframework.web.servlet.view.json.MappingJackson2JsonView">
</bean>
</list>
</property>
<property name="ignoreAcceptHeader" value="true" />
</bean>
<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass"
value="org.springframework.web.servlet.view.JstlView" />
<property name="prefix" value="/WEB-INF/jsps/" />
<property name="suffix" value=".jsp" />
</bean>
<!--200*1024*1024即200M resolveLazily属性启用是为了推迟文件解析，以便捕获文件大小异常 -->
<bean id="multipartResolver"
class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="maxUploadSize" value="209715200" />
<property name="defaultEncoding" value="UTF-8" />
<property name="resolveLazily" value="true" />
</bean>
</beans>
//本方法将处理 /courses/view?courseId=123 形式的URL
@RequestMapping(value="/view", method=RequestMethod.GET)
public String viewCourse(@RequestParam("courseId") Integer courseId,
Model model) {
log.debug("In viewCourse, courseId = {}", courseId);
Course course = courseService.getCoursebyId(courseId);
model.addAttribute(course);
return "course_overview";
}
//本方法将处理 /courses/view2/123 形式的URL
@RequestMapping("/view2/{courseId}")
public String viewCourse2(@PathVariable("courseId") Integer courseId,
Map<String, Object> model) {
log.debug("In viewCourse2, courseId = {}", courseId);
Course course = courseService.getCoursebyId(courseId);
model.put("course",course);
return "course_overview";
}
//本方法将处理 /courses/view3?courseId=123 形式的URL
@RequestMapping("/view3")
public String viewCourse3(HttpServletRequest request) {
Integer courseId = Integer.valueOf(request.getParameter("courseId"));
Course course = courseService.getCoursebyId(courseId);
request.setAttribute("course",course);
return "course_overview";
}
@RequestMapping(value="/admin", method = RequestMethod.GET, params = "add")
public String createCourse(){
return "course_admin/edit";
}
@RequestMapping(value="/save", method = RequestMethod.POST)
public String doSave(@ModelAttribute Course course){
log.debug("Info of Course:");
log.debug(ReflectionToStringBuilder.toString(course));
//在此进行业务操作，比如数据库持久化
course.setCourseId(123);
return "redirect:view2/"+course.getCourseId();
}
此处多了一个注解@ModelAttribute("user")，它的作用是将该绑定的命令对象以“user”为名称添加到模型对象中供视图页面展示使用。我们此时可以在视图页面使用${user.username}来获取绑定的命令对象的属性。
7：用到HttpServletRequest 需要引入
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
</dependency>
@RequestMapping(value="/{courseId}",method=RequestMethod.GET)
public @ResponseBody Course getCourseInJson(@PathVariable Integer courseId){
return courseService.getCoursebyId(courseId);
}
@RequestMapping(value="/jsontype/{courseId}",method=RequestMethod.GET)
public ResponseEntity<Course> getCourseInJson2(@PathVariable Integer courseId){
Course course = courseService.getCoursebyId(courseId);
return new ResponseEntity<Course>(course, HttpStatus.OK);
}
需要引入
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${jackson.version}</version>
</dependency>
以及配置ViewResolver
