快速学习-拦截器运行流程图解

spring-aop-4.0.0.RELEASE.jar
spring-beans-4.0.0.RELEASE.jar
spring-context-4.0.0.RELEASE.jar
spring-core-4.0.0.RELEASE.jar
spring-expression-4.0.0.RELEASE.jar
commons-logging-1.1.3.jar
spring-web-4.0.0.RELEASE.jar
spring-webmvc-4.0.0.RELEASE.jar

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

<?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/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
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-4.0.xsd">
 
<!-- 设置扫描组件的包 -->
<context:component-scan base-package="com.atguigu.springmvc"/>
 
<!-- 配置视图解析器 -->
<bean id="internalResourceViewResolver"
    class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/"/>
<property name="suffix" value=".jsp"/>
</bean>
 
</beans>

<a href="helloworld">Hello World</a>

@Controller
public class HelloWorldHandler { 
    @RequestMapping("/helloworld")
    public String testHello(){ 
        System.out.println("Hello,SpringMVC..."); 
        return "success";
    } 
}

<h3>Success Page</h3>

四月 20, 2016 11:53:19 上午 org.springframework.web.servlet.PageNotFound noHandlerFound
警告: No mapping found for HTTP request with URI [/SpringMVC_09_WorkFlow/helloworld2] in DispatcherServlet with name 'springDispatcherServlet'

四月 20, 2016 11:54:16 上午 org.springframework.web.servlet.PageNotFound noHandlerFound
警告: No mapping found for HTTP request with URI [/SpringMVC_09_WorkFlow/test.html] in DispatcherServlet with name 'springDispatcherServlet'

org.springframework.web.servlet.HandlerExecutionChain
Handler execution chain, consisting of handler object and any handler interceptors. Returned by
 HandlerMapping's HandlerMapping.getHandler method.

org.springframework.web.servlet.HandlerMapping
Interface to be implemented by objects that define a mapping between requests and handler objects. 
This class can be implemented by application developers, although this is not necessary, as org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping and org.springframework.web.servlet.handler.SimpleUrlHandlerMapping are included in the framework. The former is the default if no HandlerMapping bean is registered in the application context. 
HandlerMapping implementations can support mapped interceptors but do not have to. A handler will always be wrapped in a HandlerExecutionChain instance, optionally accompanied by some HandlerInterceptor instances. The DispatcherServlet will first call each HandlerInterceptor's preHandle method in the given order, finally invoking the handler itself if all preHandle methods have returned true. 
The ability to parameterize this mapping is a powerful and unusual capability of this MVC framework. For example, it is possible to write a custom mapping based on session state, cookie state or many other variables. No other MVC framework seems to be equally flexible. 
Note: Implementations can implement the org.springframework.core.Ordered interface to be able to specify a sorting order and thus a priority for getting applied by DispatcherServlet. Non-Ordered instances get treated as lowest priority.