Spring MVC介绍(一)之 Spring MVC体系结构与执行流程
Spring MVC是Spring的一个模块,包含Web MVC、Framework,Web Views,JSP等等。
其中MVC分别对应:Model,View,Controller,本质上SpirngMVC还是使用Servlet进行处理,并在其基础上进行了封装,简化了开发流程,提高易用性,并使得逻辑结构变得非常清晰。
Spring MVC对比Servlet简化开发流程的方面有:
- 基于注解的url映射
- http表单参数转换
- 全局统一异常处理
- 拦截器的实现
等等。
Spring MVC 体系结构
HandlerMapping : url与控制器的映射
package org.springframework.web.servlet;
import javax.servlet.http.HttpServletRequest;
public interface HandlerMapping {
String PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE = HandlerMapping.class.getName() + ".pathWithinHandlerMapping";
String BEST_MATCHING_PATTERN_ATTRIBUTE = HandlerMapping.class.getName() + ".bestMatchingPattern";
String INTROSPECT_TYPE_LEVEL_MAPPING = HandlerMapping.class.getName() + ".introspectTypeLevelMapping";
String URI_TEMPLATE_VARIABLES_ATTRIBUTE = HandlerMapping.class.getName() + ".uriTemplateVariables";
String MATRIX_VARIABLES_ATTRIBUTE = HandlerMapping.class.getName() + ".matrixVariables";
String PRODUCIBLE_MEDIA_TYPES_ATTRIBUTE = HandlerMapping.class.getName() + ".producibleMediaTypes";
HandlerExecutionChain getHandler(HttpServletRequest var1) throws Exception;
}
HandlerAdapter : 控制器与执行适配器
package org.springframework.web.servlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public interface HandlerAdapter {
boolean supports(Object var1);
ModelAndView handle(HttpServletRequest var1, HttpServletResponse var2, Object var3) throws Exception;
long getLastModified(HttpServletRequest var1, Object var2);
}
ViewResolver : 视图仓库
package org.springframework.web.servlet;
import java.util.Locale;
public interface ViewResolver {
View resolveViewName(String var1, Locale var2) throws Exception;
}
View : 视图
package org.springframework.web.servlet;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public interface View {
String RESPONSE_STATUS_ATTRIBUTE = View.class.getName() + ".responseStatus";
String PATH_VARIABLES = View.class.getName() + ".pathVariables";
String SELECTED_CONTENT_TYPE = View.class.getName() + ".selectedContentType";
String getContentType();
void render(Map<String, ?> var1, HttpServletRequest var2, HttpServletResponse var3) throws Exception;
}
HandlerExceptionResolver : 异常捕捉器
package org.springframework.web.servlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public interface HandlerExceptionResolver {
ModelAndView resolveException(HttpServletRequest var1, HttpServletResponse var2, Object var3, Exception var4);
}
HandlerInterceptor : 拦截器
package org.springframework.web.servlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public interface HandlerInterceptor {
boolean preHandle(HttpServletRequest var1, HttpServletResponse va