03-MVC执行流程-参数解析与Model

重要组件

准备Model，Controller

@Configuration
public class WebConfig {@ControllerAdvicestatic class MyControllerAdvice {@ModelAttribute("b")public String bar() {return "bar";}}@Controllerstatic class Controller1 {@ResponseStatus(HttpStatus.OK)  // 添加此注解  这里不测试返回值处理器public ModelAndView foo(@ModelAttribute("u") User user) {System.out.println("Controller1.foo");System.out.println("user = " + user);return null;}}@Datastatic class User {private String name;}
}

准备参数解析器

private static HandlerMethodArgumentResolverComposite argumentResolverComposite(AnnotationConfigApplicationContext annotationConfigApplicationContext) {DefaultListableBeanFactory beanFactory = annotationConfigApplicationContext.getDefaultListableBeanFactory();HandlerMethodArgumentResolverComposite resolverComposite = new HandlerMethodArgumentResolverComposite();resolverComposite.addResolvers(// @RequestParam参数解析器       false表示参数上必须有注解才会解析new RequestParamMethodArgumentResolver(beanFactory, false),// @PathVariablenew PathVariableMethodArgumentResolver(),// @RequestHeadernew RequestHeaderMethodArgumentResolver(beanFactory),// @CookieValuenew ServletCookieValueMethodArgumentResolver(beanFactory),// Spring表达式参数解析器new ExpressionValueMethodArgumentResolver(beanFactory),// HttpServletRequestnew ServletRequestMethodArgumentResolver(),// 是否不需要注解@ModelAttribute false：需要  即没有@ModelAttribute的实体参数不解析new ServletModelAttributeMethodProcessor(false),// @RequestBodynew RequestResponseBodyMethodProcessor(CollUtil.newArrayList(new MappingJackson2HttpMessageConverter())),/***是否不需要注解@ModelAttribute true：不需要  即没有@ModelAttribute的实体参数也解析* 注意！！！  这个解析器必须放在@RequestBody解析器后面，否则这个解析器将会优先被使用去解析*/new ServletModelAttributeMethodProcessor(true),/*** @RequestParam 参数解析器 true表示参数上没有注解也会解析* 注意！！！  这个解析器必须放在后面 否则其它类型参数将使用这个解析器解析*/new RequestParamMethodArgumentResolver(beanFactory, true));return resolverComposite;}

测试MVC流程

// 1. 准备容器
AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(WebConfig.class);// 2. 准备RequestMappingHandlerAdapter  测试：获取模型工厂并获取初始化时配置在ControllerAdvice中的模型数据
RequestMappingHandlerAdapter requestMappingHandlerAdapter = new RequestMappingHandlerAdapter();
requestMappingHandlerAdapter.setApplicationContext(applicationContext);
requestMappingHandlerAdapter.afterPropertiesSet();
Method getModelFactoryMethod = RequestMappingHandlerAdapter.class.getDeclaredMethod("getModelFactory", HandlerMethod.class, WebDataBinderFactory.class);
getModelFactoryMethod.setAccessible(true);// 3. 准备请求
MockHttpServletRequest mockHttpServletRequest = new MockHttpServletRequest();
mockHttpServletRequest.setParameter("name", "zhoujunlin");
ServletWebRequest servletWebRequest = new ServletWebRequest(mockHttpServletRequest);// 4. 准备servletInvocableHandlerMethod
ServletInvocableHandlerMethod servletInvocableHandlerMethod = new ServletInvocableHandlerMethod(new Controller1(), Controller1.class.getDeclaredMethod("foo", WebConfig.User.class));
// 这里没有特殊参数绑定  入参传null
ServletRequestDataBinderFactory servletRequestDataBinderFactory = new ServletRequestDataBinderFactory(null, null);
servletInvocableHandlerMethod.setDataBinderFactory(servletRequestDataBinderFactory);
servletInvocableHandlerMethod.setParameterNameDiscoverer(new DefaultParameterNameDiscoverer());
servletInvocableHandlerMethod.setHandlerMethodArgumentResolvers(argumentResolverComposite(applicationContext));
// 暂不研究返回值处理器// 5. 准备ModelAndViewContainer容器
ModelAndViewContainer modelAndViewContainer = new ModelAndViewContainer();// 6. 获取模型工厂并初始化模型数据
ModelFactory modelFactory = (ModelFactory) getModelFactoryMethod.invoke(requestMappingHandlerAdapter, servletInvocableHandlerMethod, servletRequestDataBinderFactory);
modelFactory.initModel(servletWebRequest, modelAndViewContainer, servletInvocableHandlerMethod);// 7. 方法执行
servletInvocableHandlerMethod.invokeAndHandle(servletWebRequest,modelAndViewContainer);System.out.println("modelAndViewContainer.getModel() = " + modelAndViewContainer.getModel());// 8. 关闭容器
applicationContext.close();