//前端控制器分派方法
protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception {
        HttpServletRequest processedRequest = request;
        HandlerExecutionChain mappedHandler = null;
        int interceptorIndex = -1;

        try {
            ModelAndView mv;
            boolean errorView = false;

            try {
                   //检查请求是否是multipart（如文件上传），如果是将通过MultipartResolver解析
                processedRequest = checkMultipart(request);
                   //步骤2、请求到处理器（页面控制器）的映射，通过HandlerMapping进行映射
                mappedHandler = getHandler(processedRequest, false);
                if (mappedHandler == null || mappedHandler.getHandler() == null) {
                    noHandlerFound(processedRequest, response);
                    return;
                }
                   //步骤3、处理器适配，即将我们的处理器包装成相应的适配器（从而支持多种类型的处理器）
                HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());

                  // 304 Not Modified缓存支持
                //此处省略具体代码

                // 执行处理器相关的拦截器的预处理（HandlerInterceptor.preHandle）
                //此处省略具体代码

                // 步骤4、由适配器执行处理器（调用处理器相应功能处理方法）
                mv = ha.handle(processedRequest, response, mappedHandler.getHandler());

                // Do we need view name translation?
                if (mv != null && !mv.hasView()) {
                    mv.setViewName(getDefaultViewName(request));
                }

                // 执行处理器相关的拦截器的后处理（HandlerInterceptor.postHandle）
                //此处省略具体代码
            }
            catch (ModelAndViewDefiningException ex) {
                logger.debug("ModelAndViewDefiningException encountered", ex);
                mv = ex.getModelAndView();
            }
            catch (Exception ex) {
                Object handler = (mappedHandler != null ? mappedHandler.getHandler() : null);
                mv = processHandlerException(processedRequest, response, handler, ex);
                errorView = (mv != null);
            }

              //步骤5 步骤6、解析视图并进行视图的渲染
　　　　　　　　//步骤5 由ViewResolver解析View（viewResolver.resolveViewName(viewName, locale)）
　　　　　　   //步骤6 视图在渲染时会把Model传入（view.render(mv.getModelInternal(), request, response);）
            if (mv != null && !mv.wasCleared()) {
                render(mv, processedRequest, response);
                if (errorView) {
                    WebUtils.clearErrorRequestAttributes(request);
                }
            }
            else {
                if (logger.isDebugEnabled()) {
                    logger.debug("Null ModelAndView returned to DispatcherServlet with name ‘" + getServletName() +
                            "‘: assuming HandlerAdapter completed request handling");
                }
            }

            // 执行处理器相关的拦截器的完成后处理（HandlerInterceptor.afterCompletion）
            //此处省略具体代码


        catch (Exception ex) {
            // Trigger after-completion for thrown exception.
            triggerAfterCompletion(mappedHandler, interceptorIndex, processedRequest, response, ex);
            throw ex;
        }
        catch (Error err) {
            ServletException ex = new NestedServletException("Handler processing failed", err);
            // Trigger after-completion for thrown exception.
            triggerAfterCompletion(mappedHandler, interceptorIndex, processedRequest, response, ex);
            throw ex;
        }

        finally {
            // Clean up any resources used by a multipart request.
            if (processedRequest != request) {
                cleanupMultipart(processedRequest);
            }
        }
    }

<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_9" 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">


    <servlet>
        <servlet-name>SpringMVCTest</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    
        <init-param>
            <param-name>ContextConfigLocation</param-name>
            <param-value>classpath:ApplicatioinContext.xml</param-value>
        </init-param>
　　　　 <load-on-startup>1</load-on-startup>

    </servlet>
    <servlet-mapping>
        <servlet-name>SpringMVCTest</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop"
    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/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx.xsd
        ">
  <!--name为访问路径     class为ModelAndView实现类-->
<bean name="/nice" class="com.gxxy.SpringMVC.SpringMVCTest"/>
<context:component-scan base-package="com.gxxy.SpringMVC.annotation"></context:component-scan>
</beans>

<bean
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="WEB-INF/views/"></property>//前缀
        <property name="suffix" value=".jsp"></property>//后缀
</bean>

package com.gxxy.SpringMVC;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;

public class SpringMVCTest implements Controller {

    @Override
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
        // 1、收集参数、验证参数
        // 2、绑定参数到命令对象
        // 3、将命令对象传入业务对象进行业务处理
        // 4、选择下一个页面
        ModelAndView modelAndView = new ModelAndView();
        // 设置逻辑视图名，视图解析器会根据该名字解析到具体的视图页面
        modelAndView.setViewName("/WEB-INF/views/Hello.jsp");
        // 添加模型数据 可以是任意的POJO对象
        modelAndView.addObject("key", "Hello World!");
        return modelAndView;
    }
}