每日归档： 2019年11月8日

类的继承关系

1. public class DispatcherServlet extends FrameworkServlet
2. public abstract class FrameworkServlet extends HttpServletBean implements ApplicationContextAware
3. public abstract class HttpServletBean extends HttpServlet implements EnvironmentCapable, EnvironmentAware
4. public abstract class javax.servlet.http.HttpServlet extends GenericServlet
5. public abstract class javax.servlet.GenericServlet implements Servlet, ServletConfig,java.io.Serializable
6. public interface javax.servlet.Servlet

代码处理流程

1. DispatcherServlet.java: doService()开始处理请求;
2. DispatcherServlet.java: getHandler() 遍历几种handler
3. AbstractHandlerMapping.java: getHandler() 获取处理类的实例
4. AbstractHandlerMapping.java: getHandler() 检查是否为跨域请求(检查代码: request.getHeader(“Origin”) != null;)
5. AbstractHandlerMethodMapping.java: lookupHandlerMethod()->实际是在addMatchingMappings()方法里获取请求url对应的Controller全限定类路径及返回参数及全限定方法名.

   (例如（因代码过长,所以折行.）：
   public 
                  java.util.List     
                           xyz.suancaiyu.complexcontrollerdemo.controller.CoffeeController.getAll()
   )
   

6. DispatcherServlet.java: doService()实际调用处理程序:mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
7. DispatcherServlet.java: doService()处理完成,并返回.

实际调用链路

其他

@RequestMapping注解的处理类: RequestMappingHandlerAdapter