Springmvc DispatcherServlet原理及用法解析

		<servlet>
    <servlet-name>SpringMVC</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:spring-mvc.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <!-- servlet-mapping -->
  <servlet-mapping>
    <servlet-name>SpringMVC</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>

@Service 
public class HelloService { 
	public String hello(String name) { 
		return "hello " + name; 
		} 
}

<?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"
    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">
  <context:component-scan base-package="org.javaboy" use-default-filters="true">
    <context:exclude-filter type="annotation"
       expression="org.springframework.stereotype.Controller"/>
  </context:component-scan>
</beans>

<context-param> 
	<param-name>contextConfigLocation</param-name> 
	<param-value>classpath:applicationContext.xml</param-value> 
</context-param> 
<listener> 
	<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener>

@org.springframework.stereotype.Controller("/hello")
  public class MyController implements Controller {
    @Autowired
    HelloService helloService;

    /**
     * 这就是一个请求处理接口 
     * * @param req 这就是前端发送来的请求 
     * * @param resp 这就是服务端给前端的响应 
     * * @return 返回值是一个 ModelAndView，Model 相当于是我们的数据模型，
     * View 是我们的视图 * @throws Exception
     */
    public ModelAndView handleRequest(HttpServletRequest req, HttpServletResponse resp) throws Exception {
      System.out.println(helloService.hello("javaboy"));
      ModelAndView mv = new ModelAndView("hello");
      mv.addObject("name", "javaboy");
      return mv;
    }
  }

<context:component-scan base-package="org.javaboy.helloworld" use-default-filters="false">  
		<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>

<!--这个是处理器映射器，这种方式，请求地址其实就是一个 Bean 的名字，然后根据这个 bean 的名字查找对应的处理器-->
<bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping" id="handlerMapping">  
	<property name="beanName" value="/hello"/>
</bean>

<bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter" id="handlerAdapter"/>
<!--视图解析器-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="viewResolver">  
	<property name="prefix" value="/jsp/"/>  
	<property name="suffix" value=".jsp"/>
</bean>