摘要：例如，將請求信息中的字符串格式參數轉換為對應方法中的類類型入參可通過的屬性注冊自定義轉換器。

請求提交給DispatchServlet

查找HandlerMapping

調用由HandlerAdapter封裝后的Handler

返回ModelAndView到DispatcherServlet

借由ViewResolver完成邏輯視圖到真實視圖的轉換

返回響應

web.xml

    
    
        contextConfigLocation
        
            /WEB-INF/applicationServlet.xml,
        
    
    
        org.springframework.web.context.ContextLoaderListener
    

    
    
        app
        org.springframework.web.servlet.DispatcherServlet
        
            logLevel
            FINE
        
        1
    

    
    
        app
        /api/*
    

子容器可以訪問父容器的bean，父容器不能訪問子容器的bean

默認采用org.springframework.web.context.ContextLoaderListener

默認使用/WEB-INF/{servlet-name}-*.xml加載子容器

DispatcherServlet初始化

protected void initStrategies(ApplicationContext context) {
    initMultipartResolver(context);
    initLocaleResolver(context);
    initThemeResolver(context);
    initHandlerMappings(context);
    initHandlerAdapters(context);
    initHandlerExceptionResolvers(context);
    initRequestToViewNameTranslator(context);
    initViewResolvers(context);
    initFlashMapManager(context);
}

默認配置: DispatcherServlet.properties

# Default implementation classes for DispatcherServlet"s strategy interfaces.
# Used as fallback when no matching beans are found in the DispatcherServlet context.
# Not meant to be customized by application developers.

org.springframework.web.servlet.LocaleResolver=org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver

org.springframework.web.servlet.ThemeResolver=org.springframework.web.servlet.theme.FixedThemeResolver

org.springframework.web.servlet.HandlerMapping=org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping,
    org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping

org.springframework.web.servlet.HandlerAdapter=org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter,
    org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter,
    org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter

org.springframework.web.servlet.HandlerExceptionResolver=org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerExceptionResolver,
    org.springframework.web.servlet.mvc.annotation.ResponseStatusExceptionResolver,
    org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver

org.springframework.web.servlet.RequestToViewNameTranslator=org.springframework.web.servlet.view.DefaultRequestToViewNameTranslator

org.springframework.web.servlet.ViewResolver=org.springframework.web.servlet.view.InternalResourceViewResolver

org.springframework.web.servlet.FlashMapManager=org.springframework.web.servlet.support.SessionFlashMapManager

@Controller(由Spring識別Handler實例)

@RequestMapping(value=, method=, params=)

@RequestMapping(value=, method=, params=)

@PathVariable，配合占位符{parameter}

@RequestParam(value=, required=, defaultValue=)

@CookieValue(value=, required=, defaultValue=)

@RequestHeader(value=, required=, defaultValue=)

HttpServletRequest, WebRequest, ServletRequest的InputStream / Reader

HttpServeltResponse, ServletResponse的OutputStream / Writer

HttpMessageConverter

使用@RequestBody / @ResponseBody；使用HttpEntity / ResponseEntity

Spring根據HTTP報文頭部的Accept指定的MIME類型，查找匹配的HttpMessageConverter

Spring MVC默認裝配AnnotationMethodHandlerAdapter，調用HttpMessageConverter

mvc命名空間的標簽會創建并注冊一個默認的DefaultAnnotationHandlerMapping和一個AnnotationMethodHandlerAdapter實例，如果上下文中存在自定義的對應組件bean，則覆蓋默認配置

app-servlet.xml

Spring MVC在調用方法前會創建一個隱含的模型對象

ModelAndView：返回值類型為ModelAndView時，方法體通過該對象添加模型數據

@ModelAttribute：入參對象添加到數據模型中

Map和Model：入參為org.springframework.ui.Model、org.springframework.ui.ModelMap或java.util.Map時，處理方法返回時，Map中的數據會自動添加到模型中

@SessionAttributes：將模型中的某個屬性暫存到HttpSession中，以便多個請求共享

Spring MVC將ServletRequest對象及處理方法的入參實例傳遞給DataBinder；

DataBinder調用ConversionService組件進行數據類型轉換、數據格式化等工作，將ServletRequest中的消息填充到入參對象中；

然后再調用Validator組件對已經綁定了請求消息數據的入參對象進行數據合法性校驗，并最終生成綁定結果BindingResult對象，其中還包含相應的校驗錯誤對象

抽取BindingResult中的入參對象及校驗錯誤對象，賦給處理方法的相應入參

例如：將請求信息中A類型參數轉換并綁定到Controller對應的處理方法的B類型入參中

基于ConversionService接口，Spring將自動識別其實現類，用于入參類型轉換，類似于C++中的自定義類型轉換。例如，將http請求信息中的字符串格式參數轉換為Controller對應方法中的類類型入參

可通過ConversionServiceFactoryBean的converters屬性注冊自定義轉換器。可接受Converter，ConverterFacotory，GenericConverter或ConditionalConverterFactory的實現類，并統一封裝到一個ConversionService的實例（即GenericConversionService）中

標簽還會注冊一個默認的ConversionService，即FormattingConversionServiceFactoryBean

例如：將請求信息中字符串類型參數轉換并綁定到Controller對應的處理方法入參中的Date類型屬性中

格式化框架定義了Formatter接口，擴展于Printer和Parser接口

Srping提供AnnotationFormatterFactory接口及兩個實現類：NumberFormatAnnotationFormatterFactory和JodaDateTimeFormatAnnotationFormatterFactory

public Class User {
    private String userId;

    @Pattern(regexp="w{4,30}")
    private String userName;

    @Length(min=2, max=100)
    private String nickName;

    @Past
    @DateTimeFormat(pattern = "yyyy-MM-dd")
    private Date birthday;

    @DecimalMin(value = "1000.00")
    @DecimalMax(value = "10000.00")
    @NumberFormat(pattern = "#,###.##")
    pirvate Long salary;
}


@RequestMapping(value = "/handle")
public void handle(@Valid User uer, BindingResult bindingResult) {
    //do something
}

    






    
    
    
    
        text/html; charset=UTF-8
    
    



    
    
        
            UTF-8
            UTF-8
            
            true
            loopCursor
            0
        
    

public interface HandlerInterceptor {

  boolean preHandle (HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception;

  void postHandle (HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception;

  void afterCompletion (HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception;
}

public interface HandlerExceptionResolver {
  ModelAndView resolveException (HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex);
}

    
    
        404
        /error
    
    
        403
        /error
    
    
        java.lang.Throwable
        /error