自拍偷在线精品自拍偷,亚洲欧美中文日韩v在线观看不卡

@ControllerAdvice注解使用及原理探究

開發(fā) 前端
@initBinder和@ModelAttribute都是請求過程中的處理,我們知道springMvc通過HandlerApapter定位到具體的方法進(jìn)行請求處理,因此查看HandlerHaper的實(shí)現(xiàn)類,發(fā)現(xiàn)RequestMappingHandlerAdapter比較符合我們的目標(biāo)。

最近在新項(xiàng)目的開發(fā)過程中,遇到了個(gè)問題,需要將一些異常的業(yè)務(wù)流程返回給前端,需要提供給前端不同的響應(yīng)碼,前端再在次基礎(chǔ)上做提示語言的國際化適配。這些異常流程涉及業(yè)務(wù)層和控制層的各個(gè)地方,如果每個(gè)地方都寫一些重復(fù)代碼顯得很冗余。

然后查詢解決方案時(shí)發(fā)現(xiàn)了@ControllerAdvice這個(gè)注解,可以對業(yè)務(wù)異常進(jìn)行統(tǒng)一處理。經(jīng)過仔細(xì)了解后,發(fā)現(xiàn)這個(gè)注解還有更多的用處,都很實(shí)用。

1 ControllerAdvice介紹

@ControllerAdvice一般和三個(gè)以下注解一塊使用,起到不同的作用,

  • @ExceptionHandler: 該注解作用于方法上,,可以捕獲到controller中拋出的一些自定義異常,統(tǒng)一進(jìn)行處理,一般用于進(jìn)行一些特定的異常處理。
  • @InitBinder:該注解作用于方法上,用于將前端請求的特定類型的參數(shù)在到達(dá)controller之前進(jìn)行處理,從而達(dá)到轉(zhuǎn)換請求參數(shù)格式的目的。
  • @ModelAttribute:該注解作用于方法和請求參數(shù)上,在方法上時(shí)設(shè)置一個(gè)值,可以直接在進(jìn)入controller后傳入該參數(shù)。

2 ControllerAdvice應(yīng)用場景

2.1@ExceptionHandler統(tǒng)一處理業(yè)務(wù)異常

@RestControllerAdvice
@Slf4j
public class GlobalExceptionHandler {
// 這里就是對各個(gè)層返回的異常進(jìn)行統(tǒng)一捕獲處理
@ExceptionHandler(value = BusinessException.class)
public ResponseData<Void> bizException(BusinessException e){
        log.error("業(yè)務(wù)異常記錄",e);
        return ResponseData.error(e.getCode(),e.getMessage());
}
}
//業(yè)務(wù)異常處代碼示例:
if(CollectionUtil.isNotEmpty(companies)){
// 通過BusinessExceptionEnum枚舉對業(yè)務(wù)異常進(jìn)行統(tǒng)一管理
throw new BusinessException(BusinessExceptionEnum.ERROR_10003);
}

需要注意的是,如果這里有多個(gè)ExceptionHandler,按照異常類的層次體系,越高層的異常,優(yōu)先級越低。

2.2@InitBinder做日期格式的統(tǒng)一處理

@RestControllerAdvice
@Slf4j
public class GlobalExceptionHandler {
// 將前端傳入的字符串時(shí)間格式轉(zhuǎn)換為LocalDate時(shí)間  
@InitBinder
    protected void initBinder(WebDataBinder binder) {
//將前端傳入的字符串格式時(shí)間數(shù)據(jù)轉(zhuǎn)為LocalDate格式的數(shù)據(jù)
        binder.registerCustomEditor(LocalDate.class, new PropertyEditorSupport() {
            @Override
            public void setAsText(String text) throws IllegalArgumentException {
                setValue(LocalDate.parse(text, DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));
            }
        });
//將前端傳入的字符串格式時(shí)間數(shù)據(jù)轉(zhuǎn)為LocalDateTime格式的數(shù)據(jù)
        binder.registerCustomEditor(LocalDateTime.class, new PropertyEditorSupport() {
            @Override
            public void setAsText(String text) throws IllegalArgumentException {
                setValue(LocalDateTime.parse(text, DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));
            }
        });
//將前端傳入的字符串格式時(shí)間數(shù)據(jù)轉(zhuǎn)為LocalTim格式的數(shù)據(jù)
        binder.registerCustomEditor(LocalTime.class, new PropertyEditorSupport() {
            @Override
            public void setAsText(String text) throws IllegalArgumentException {
                setValue(LocalTime.parse(text, DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));
            }
        });
    }
}
// controller進(jìn)行參數(shù)綁定
public ResponseData<List<WorkCalendarVo>> listWorkCalendar(@RequestParam LocalDate  date){}

2.3 ModelAttribute提前綁定全局user對象

// 這里@ModelAttribute("loginUser")標(biāo)注的modelAttribute()方法表示會在Controller方法之前將user設(shè)置到contoller里的已綁定參數(shù)里
    @ModelAttribute("loginUser")
    public User setLoginUser(HttpServletRequest request) {
        return LoginContextUtils.getLoginUser(request);
    }
// 使用
    @PostMapping("/list")
    public ResponseData<IPage<EmployeeVo>> listEmployee(@ModelAttribute("loginUser") User user, @RequestBody EmployeeSearch employeeSearch){
        return ResponseData.success(employeeService.listEmployee(user, employeeSearch));
    }

3 ControllerAdvice作用原理探究

在探究ControllerAdvice如何生效時(shí),不得不提到springMvc繞不過的DispatcherServlet,這個(gè)類是SpringMVC統(tǒng)一的入口,所有的請求都通過它,里面的一些初始化方法如下。

public class DispatcherServlet extends FrameworkServlet {
    // ......
    protected void initStrategies(ApplicationContext context) {
        initMultipartResolver(context);
        initLocaleResolver(context);
        initThemeResolver(context);
        initHandlerMappings(context);
//請求處理的adapter
        initHandlerAdapters(context);
// 異常響應(yīng)處理的resolver
        initHandlerExceptionResolvers(context);
        initRequestToViewNameTranslator(context);
        initViewResolvers(context);
        initFlashMapManager(context);
    }
    // ......
}

3.1@initBinder和@ModelAttribute的作用原理

@initBinder和@ModelAttribute都是請求過程中的處理,我們知道springMvc通過HandlerApapter定位到具體的方法進(jìn)行請求處理,因此查看HandlerHaper的實(shí)現(xiàn)類,發(fā)現(xiàn)RequestMappingHandlerAdapter比較符合我們的目標(biāo)

點(diǎn)進(jìn)去RequestMappingHandlerAdapter后發(fā)現(xiàn)里面的一個(gè)方法如下

@Override
    public void afterPropertiesSet() {
        // Do this first, it may add ResponseBody advice beans
// 這里會添加ResponseBody advice beans
        initControllerAdviceCache();

        if (this.argumentResolvers == null) {
            List<HandlerMethodArgumentResolver> resolvers = getDefaultArgumentResolvers();
            this.argumentResolvers = new HandlerMethodArgumentResolverComposite().addResolvers(resolvers);
        }
        if (this.initBinderArgumentResolvers == null) {
            List<HandlerMethodArgumentResolver> resolvers = getDefaultInitBinderArgumentResolvers();
            this.initBinderArgumentResolvers = new HandlerMethodArgumentResolverComposite().addResolvers(resolvers);
        }
        if (this.returnValueHandlers == null) {
            List<HandlerMethodReturnValueHandler> handlers = getDefaultReturnValueHandlers();
            this.returnValueHandlers = new HandlerMethodReturnValueHandlerComposite().addHandlers(handlers);
        }
    }
// 這里找到contollerAdvice注解的類,緩存里面的方法
private void initControllerAdviceCache() {
        if (getApplicationContext() == null) {
            return;
        }
// 找到@ControllerAdvice注解標(biāo)注的類
        List<ControllerAdviceBean> adviceBeans = ControllerAdviceBean.findAnnotatedBeans(getApplicationContext());

        List<Object> requestResponseBodyAdviceBeans = new ArrayList<>();

        for (ControllerAdviceBean adviceBean : adviceBeans) {
            Class<?> beanType = adviceBean.getBeanType();
            if (beanType == null) {
                throw new IllegalStateException("Unresolvable type for ControllerAdviceBean: " + adviceBean);
            }
// 找到所有ModelAttribute標(biāo)注的方法進(jìn)行緩存,就可以使用了
            Set<Method> attrMethods = MethodIntrospector.selectMethods(beanType, MODEL_ATTRIBUTE_METHODS);
            if (!attrMethods.isEmpty()) {
                this.modelAttributeAdviceCache.put(adviceBean, attrMethods);
            }
// 找到所有initBinder注解標(biāo)注的方法進(jìn)行緩存,就可以使用了
            Set<Method> binderMethods = MethodIntrospector.selectMethods(beanType, INIT_BINDER_METHODS);
            if (!binderMethods.isEmpty()) {
                this.initBinderAdviceCache.put(adviceBean, binderMethods);
            }
            if (RequestBodyAdvice.class.isAssignableFrom(beanType) || ResponseBodyAdvice.class.isAssignableFrom(beanType)) {
                requestResponseBodyAdviceBeans.add(adviceBean);
            }
        }

        if (!requestResponseBodyAdviceBeans.isEmpty()) {
            this.requestResponseBodyAdvice.addAll(0, requestResponseBodyAdviceBeans);
        }
// ......日志處理
    }

3.2@ExceptionHandler注解的作用原理

相同的思路,@ExceptionHandler是響應(yīng)時(shí)的處理,因此需要找到對應(yīng)的Resolver,進(jìn)入initHandlerExceptionResolvers(context)方法,

屬性填充后會進(jìn)行afterPropertiesSet方法,這個(gè)方法可以用在一些特殊情況中,也就是某個(gè)對象的某個(gè)屬性需要經(jīng)過外界得到,比如說查詢數(shù)據(jù)庫等方式,這時(shí)候可以用到spring的該特性,只需要實(shí)現(xiàn)InitializingBean。

@Override
    public void afterPropertiesSet() {
        // Do this first, it may add ResponseBodyAdvice beans
        initExceptionHandlerAdviceCache();

        if (this.argumentResolvers == null) {
            List<HandlerMethodArgumentResolver> resolvers = getDefaultArgumentResolvers();
            this.argumentResolvers = new HandlerMethodArgumentResolverComposite().addResolvers(resolvers);
        }
        if (this.returnValueHandlers == null) {
            List<HandlerMethodReturnValueHandler> handlers = getDefaultReturnValueHandlers();
            this.returnValueHandlers = new HandlerMethodReturnValueHandlerComposite().addHandlers(handlers);
        }
    }

private void initExceptionHandlerAdviceCache() {
        if (getApplicationContext() == null) {
            return;
        }

        List<ControllerAdviceBean> adviceBeans = ControllerAdviceBean.findAnnotatedBeans(getApplicationContext());
        for (ControllerAdviceBean adviceBean : adviceBeans) {
            Class<?> beanType = adviceBean.getBeanType();
            if (beanType == null) {
                throw new IllegalStateException("Unresolvable type for ControllerAdviceBean: " + adviceBean);
            }
// 這里找到ExceptionHandler注解標(biāo)注的方法進(jìn)行緩存,后面就可以使用了
            ExceptionHandlerMethodResolver resolver = new ExceptionHandlerMethodResolver(beanType);
            if (resolver.hasExceptionMappings()) {
                this.exceptionHandlerAdviceCache.put(adviceBean, resolver);
            }
            if (ResponseBodyAdvice.class.isAssignableFrom(beanType)) {
                this.responseBodyAdvice.add(adviceBean);
            }
        }
// ......日志處理
    }

在啟動spring時(shí)debug發(fā)現(xiàn)最終也會走到這里對@ExceptionHander注解的方法已經(jīng)緩存

當(dāng)Controller拋出異常時(shí),DispatcherServlet通過ExceptionHandlerExceptionResolver來解析異常,而ExceptionHandlerExceptionResolver又通過ExceptionHandlerMethodResolver 來解析異常, ExceptionHandlerMethodResolver 最終解析異常找到適用的@ExceptionHandler標(biāo)注的方法是這里:

@Nullable
    public Method resolveMethodByExceptionType(Class<? extends Throwable> exceptionType) {
        Method method = this.exceptionLookupCache.get(exceptionType);
        if (method == null) {
            method = getMappedMethod(exceptionType);
            this.exceptionLookupCache.put(exceptionType, method);
        }
        return (method != NO_MATCHING_EXCEPTION_HANDLER_METHOD ? method : null);
    }

4 用具體的調(diào)用過程,驗(yàn)證上面的推測

本部分通過對DispatcherServlet的調(diào)用過程跟蹤,梳理出ControllerAdvice的作用原理,以@InitBinder主節(jié)點(diǎn)生效過程為例。

首選是dispathServlet在初始化過程中,初始化RequestMappingHandlerAdapter過程中打斷點(diǎn)發(fā)現(xiàn),initBinder已經(jīng)緩存進(jìn)來了。

然后是dispatcherServlet的調(diào)用流程圖,驗(yàn)證下是initBinder注解是否生效。

DispatcherServlet 通過doService()方法開始調(diào)用,主要邏輯包括 設(shè)置 request ,通過doDispatch() 進(jìn)行請求分發(fā)處理。

doDispatch() 的主要過程是通過 HandlerMapping 獲取 Handler,再找到用于執(zhí)行它的 HandlerAdapter,執(zhí)行 Handler 后得到 ModelAndView ,ModelAndView 是連接“業(yè)務(wù)邏輯層”與“視圖展示層”的橋梁。

4.1 DispathcerServlet的doDispatch方法

在入口處找到要執(zhí)行的HandlerAdapter,調(diào)用handle方法繼續(xù)

protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception {
        HttpServletRequest processedRequest = request;
        HandlerExecutionChain mappedHandler = null;
        boolean multipartRequestParsed = false;

        WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request);

        try {
            ModelAndView mv = null;
            Exception dispatchException = null;

            try {
                processedRequest = checkMultipart(request);
                multipartRequestParsed = (processedRequest != request);

                // Determine handler for the current request.
// 找到執(zhí)行鏈,根據(jù)請求路徑匹配到controller的方法
                mappedHandler = getHandler(processedRequest);
                if (mappedHandler == null) {
                    noHandlerFound(processedRequest, response);
                    return;
                }

                // Determine handler adapter for the current request.
// 找到對應(yīng)的HandlerAdapter,執(zhí)行鏈中的handler類型為HandlerMethod的.
                HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());

                // Process last-modified header, if supported by the handler.
                String method = request.getMethod();
                boolean isGet = HttpMethod.GET.matches(method);
                if (isGet || HttpMethod.HEAD.matches(method)) {
                    long lastModified = ha.getLastModified(request, mappedHandler.getHandler());
                    if (new ServletWebRequest(request, response).checkNotModified(lastModified) && isGet) {
                        return;
                    }
                }

                if (!mappedHandler.applyPreHandle(processedRequest, response)) {
                    return;
                }

                // Actually invoke the handler. 真正進(jìn)行處理的地方
                mv = ha.handle(processedRequest, response, mappedHandler.getHandler());

                if (asyncManager.isConcurrentHandlingStarted()) {
                    return;
                }

                applyDefaultViewName(processedRequest, mv);
                mappedHandler.applyPostHandle(processedRequest, response, mv);
            ..........
    }

4.2 RequestmappingHanderApapter對@initBInder注解緩存方法進(jìn)行處理

找到對應(yīng)的handlerAdapter后進(jìn)入invokeHandlerMethod()方法,在這里通過構(gòu)建WebDataBinderFactory對initBinder注解進(jìn)行構(gòu)建,供后續(xù)使用,具體邏輯如下。
通過getDataBinderFactory()方法從之前緩存的Map> initBinderAdviceCache中生成binderFactory

@Nullable
    protected ModelAndView invokeHandlerMethod(HttpServletRequest request,
            HttpServletResponse response, HandlerMethod handlerMethod) throws Exception {

        ServletWebRequest webRequest = new ServletWebRequest(request, response);
        try {
//根據(jù)initBinder注解,獲取對應(yīng)的factory,主要成員是InvocableHandlerMethod,就包括之前緩存的。
            WebDataBinderFactory binderFactory = getDataBinderFactory(handlerMethod);
            ModelFactory modelFactory = getModelFactory(handlerMethod, binderFactory);
// 創(chuàng)建可調(diào)用的對象,進(jìn)行調(diào)用邏輯處理
            ServletInvocableHandlerMethod invocableMethod = createInvocableHandlerMethod(handlerMethod);
            if (this.argumentResolvers != null) {
                invocableMethod.setHandlerMethodArgumentResolvers(this.argumentResolvers);
            }
            if (this.returnValueHandlers != null) {
                invocableMethod.setHandlerMethodReturnValueHandlers(this.returnValueHandlers);
            }
// binderFactory設(shè)置進(jìn)invocableMethod,
            invocableMethod.setDataBinderFactory(binderFactory);
            invocableMethod.setParameterNameDiscoverer(this.parameterNameDiscoverer);

            ModelAndViewContainer mavContainer = new ModelAndViewContainer();
            mavContainer.addAllAttributes(RequestContextUtils.getInputFlashMap(request));
            modelFactory.initModel(webRequest, mavContainer, invocableMethod);
            mavContainer.setIgnoreDefaultModelOnRedirect(this.ignoreDefaultModelOnRedirect);

            AsyncWebRequest asyncWebRequest = WebAsyncUtils.createAsyncWebRequest(request, response);
            asyncWebRequest.setTimeout(this.asyncRequestTimeout);

            WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request);
            asyncManager.setTaskExecutor(this.taskExecutor);
            asyncManager.setAsyncWebRequest(asyncWebRequest);
            asyncManager.registerCallableInterceptors(this.callableInterceptors);
            asyncManager.registerDeferredResultInterceptors(this.deferredResultInterceptors);

            if (asyncManager.hasConcurrentResult()) {
                Object result = asyncManager.getConcurrentResult();
                mavContainer = (ModelAndViewContainer) asyncManager.getConcurrentResultContext()[0];
                asyncManager.clearConcurrentResult();
                LogFormatUtils.traceDebug(logger, traceOn -> {
                    String formatted = LogFormatUtils.formatValue(result, !traceOn);
                    return "Resume with async result [" + formatted + "]";
                });
                invocableMethod = invocableMethod.wrapConcurrentResult(result);
            }
// 繼續(xù)進(jìn)行處理
            invocableMethod.invokeAndHandle(webRequest, mavContainer);
            if (asyncManager.isConcurrentHandlingStarted()) {
                return null;
            }

            return getModelAndView(mavContainer, modelFactory, webRequest);
        }
        finally {
            webRequest.requestCompleted();
        }
    }
// 生成WebDataBinderFactory的具體邏輯
private WebDataBinderFactory getDataBinderFactory(HandlerMethod handlerMethod) throws Exception {
        Class<?> handlerType = handlerMethod.getBeanType();
        Set<Method> methods = this.initBinderCache.get(handlerType);
        if (methods == null) {
            methods = MethodIntrospector.selectMethods(handlerType, INIT_BINDER_METHODS);
            this.initBinderCache.put(handlerType, methods);
        }
        List<InvocableHandlerMethod> initBinderMethods = new ArrayList<>();
        // Global methods first 獲取之前項(xiàng)目啟動緩存的initMethod
        this.initBinderAdviceCache.forEach((controllerAdviceBean, methodSet) -> {
            if (controllerAdviceBean.isApplicableToBeanType(handlerType)) {
                Object bean = controllerAdviceBean.resolveBean();
                for (Method method : methodSet) {
                    initBinderMethods.add(createInitBinderMethod(bean, method));
                }
            }
        });
        for (Method method : methods) {
            Object bean = handlerMethod.getBean();
            initBinderMethods.add(createInitBinderMethod(bean, method));
        }
        return createDataBinderFactory(initBinderMethods);
    }

經(jīng)過上面的處理,發(fā)現(xiàn)initBinder標(biāo)注的注解方法已經(jīng)成功緩存進(jìn)bindFactory。

4.3 繼續(xù)調(diào)用getMethodArgumentValues進(jìn)行后續(xù)處理

繼續(xù)往下跟蹤,進(jìn)入InvocableHandlerMethod的invokeForRequest方法,里面有g(shù)etMethodArgumentValues方法,會對請求參數(shù)進(jìn)行處理。
最終使用AbstractNamedValueMethodArgumentResolver的resolveArgument()方法對請求字符串格式數(shù)據(jù)進(jìn)行處理

// 請求Controller方法如下    
public ResponseData<IPage<CompanyVo>> listCompany(HttpServletRequest servletRequest, @RequestBody CompanySearch companySearch, @RequestParam LocalDate localDate){
       getLoginUser(servletRequest);
        return ResponseData.success(companyService.listCompany(companySearch));
    }

protected Object[] getMethodArgumentValues(NativeWebRequest request, @Nullable ModelAndViewContainer mavContainer,
            Object... providedArgs) throws Exception {
// 得到方法的參數(shù)列表
        MethodParameter[] parameters = getMethodParameters();
        if (ObjectUtils.isEmpty(parameters)) {
            return EMPTY_ARGS;
        }

        Object[] args = new Object[parameters.length];
// 循環(huán)如處理請求參數(shù)
        for (int i = 0; i < parameters.length; i++) {
            MethodParameter parameter = parameters[i];
            parameter.initParameterNameDiscovery(this.parameterNameDiscoverer);
            args[i] = findProvidedArgument(parameter, providedArgs);
            if (args[i] != null) {
                continue;
            }
            if (!this.resolvers.supportsParameter(parameter)) {
                throw new IllegalStateException(formatArgumentError(parameter, "No suitable resolver"));
            }
            try {
// 真正進(jìn)行參數(shù)處理的地方
                args[i] = this.resolvers.resolveArgument(parameter, mavContainer, request, this.dataBinderFactory);
            }
            catch (Exception ex) {
                // Leave stack trace for later, exception may actually be resolved and handled...
                if (logger.isDebugEnabled()) {
                    String exMsg = ex.getMessage();
                    if (exMsg != null && !exMsg.contains(parameter.getExecutable().toGenericString())) {
                        logger.debug(formatArgumentError(parameter, exMsg));
                    }
                }
                throw ex;
            }
        }
        return args;
    }

// 最終會使用AbstractNamedValueMethodArgumentResolver來進(jìn)行處理
public final Object resolveArgument(MethodParameter parameter, @Nullable ModelAndViewContainer mavContainer,
            NativeWebRequest webRequest, @Nullable WebDataBinderFactory binderFactory) throws Exception {

        NamedValueInfo namedValueInfo = getNamedValueInfo(parameter);
        MethodParameter nestedParameter = parameter.nestedIfOptional();
// 得到請求參數(shù)名稱為"localdate"
        Object resolvedName = resolveEmbeddedValuesAndExpressions(namedValueInfo.name);
        if (resolvedName == null) {
            throw new IllegalArgumentException(
                    "Specified name must not resolve to null: [" + namedValueInfo.name + "]");
        }
// 獲取請求的locadate的值,此時(shí)為字符串格式"yyyy-mm-dd"
        Object arg = resolveName(resolvedName.toString(), nestedParameter, webRequest);
        if (arg == null) {
            if (namedValueInfo.defaultValue != null) {
                arg = resolveEmbeddedValuesAndExpressions(namedValueInfo.defaultValue);
            }
            else if (namedValueInfo.required && !nestedParameter.isOptional()) {
                handleMissingValue(namedValueInfo.name, nestedParameter, webRequest);
            }
            arg = handleNullValue(namedValueInfo.name, arg, nestedParameter.getNestedParameterType());
        }
        else if ("".equals(arg) && namedValueInfo.defaultValue != null) {
            arg = resolveEmbeddedValuesAndExpressions(namedValueInfo.defaultValue);
        }
// 這里就會使用bindFactory進(jìn)行處理
        if (binderFactory != null) {
            WebDataBinder binder = binderFactory.createBinder(webRequest, null, namedValueInfo.name);
            try {
// 經(jīng)過這里進(jìn)行處理,輸入的string類型就會轉(zhuǎn)為LocalDate了
                arg = binder.convertIfNecessary(arg, parameter.getParameterType(), parameter);
            }
            catch (ConversionNotSupportedException ex) {
                throw new MethodArgumentConversionNotSupportedException(arg, ex.getRequiredType(),
                        namedValueInfo.name, parameter, ex.getCause());
            }
            catch (TypeMismatchException ex) {
                throw new MethodArgumentTypeMismatchException(arg, ex.getRequiredType(),
                        namedValueInfo.name, parameter, ex.getCause());
            }
            // Check for null value after conversion of incoming argument value
            if (arg == null && namedValueInfo.defaultValue == null &&
                    namedValueInfo.required && !nestedParameter.isOptional()) {
                handleMissingValueAfterConversion(namedValueInfo.name, nestedParameter, webRequest);
            }
        }

        handleResolvedValue(arg, namedValueInfo.name, parameter, mavContainer, webRequest);

        return arg;
    }

最后附上上面調(diào)用過程中一些類的介紹

以上就是ControllerAdivce的全介紹。通過對源碼的學(xué)習(xí),加深了對HTTP請求過程的理解。

參考:https://blog.csdn.net/zmm__1377445292/article/details/116158554

作者:京東物流 付鵬嘎

來源:京東云開發(fā)者社區(qū) 自猿其說Tech

責(zé)任編輯:武曉燕 來源: 今日頭條
相關(guān)推薦

2010-09-15 15:59:11

CSS hack

2019-01-10 08:24:06

2010-08-27 09:29:40

CSSbehavior

2023-05-05 07:39:04

Spring事務(wù)面試

2017-05-18 15:02:36

AndroidGC原理JVM內(nèi)存回收

2022-10-30 15:00:50

2010-09-16 14:42:44

JVM

2021-10-27 16:52:37

LayoutInfl源碼解析

2014-04-02 17:10:00

虛擬應(yīng)用工作原理

2011-12-22 14:27:11

2014-04-15 15:45:22

Java8Java8教程

2022-03-17 08:55:43

本地線程變量共享全局變量

2024-05-21 09:01:00

2023-02-07 09:17:19

Java注解原理

2014-04-15 09:53:54

Java8類型注解

2024-12-17 08:28:30

2024-08-28 08:00:00

2021-12-30 12:30:01

Java注解編譯器

2020-09-04 13:30:43

Java自定義代碼

2010-09-29 14:54:34

J2MEHashtable
點(diǎn)贊
收藏

51CTO技術(shù)棧公眾號