spring mvc源码分析

1.传统xml配置方式

web.xml里面配置：org.springframework.web.servlet.DispatcherServlet，处理项目的spring配置文件：classpath*:wly-servlet.xml

2.DispatcherServlet

doService

暴露DispatcherServlet中从request获取的属性，并且委派给doDispatch处理

doDispatch

step1:

// Determine handler for the current request.
mappedHandler = getHandler(processedRequest);

3.wly-servlet.xml

在这个配置文件里面配置了很多由spring负责创建的bean实例：包括controller和servlet类
##
处理bean.name和url映射关系，将url交给 //handlerName:"/wang" //resolvedHandler:com.wang.controller.WangController@4e2c46ed resolvedHandler = getApplicationContext().getBean(handlerName); ... this.handlerMap.put(urlPath, resolvedHandler);//其实就是把url和bean的映射关系放到了一个map里面
##
```
handler包装为适配器
//根据当前handler获取handlerexecuteChain

//根据handler的类型获取handler的适配器
protected HandlerAdapter getHandlerAdapter(Object handler) throws ServletException {
for (HandlerAdapter ha : this.handlerAdapters) {
if (logger.isTraceEnabled()) {
logger.trace("Testing handler adapter [" + ha + "]");
}
//根据handler instanceof Controller判断使用什么适配器类代替当前handler
if (ha.supports(handler)) {
return ha;
}
}
throw new ServletException("No adapter for handler [" + handler +
"]: The DispatcherServlet configuration needs to include a HandlerAdapter that supports this handler");
}

。。。
//ha.supports(handler)方法
@Override
public boolean supports(Object handler) {
return (handler instanceof Controller);
}

// 实际调用对应handler的方法
mv = ha.handle(processedRequest, response, mappedHandler.getHandler());

//执行完具体的handler方法后，通过拦截器处理视图信息：
applyDefaultViewName(processedRequest, mv);//设置modelview对象
//通过
mappedHandler.applyPostHandle(processedRequest, response, mv);
[org.springframework.web.servlet.handler.AbstractUrlHandlerMapping$PathExposingHandlerInterceptor@46dafc9f,
org.springframework.web.servlet.resource.ResourceUrlProviderExposingInterceptor@1faa1cba]
```

视图处理器，将逻辑视图转转成物理视图