Spring Boot 日期時(shí)間處理總結(jié)，寫的太好了，建議收藏！

來源：juejin.im/post/5e62817fe51d4526d05962a2

項(xiàng)目中使用LocalDateTime系列作為DTO中時(shí)間的數(shù)據(jù)類型，但是SpringMVC收到參數(shù)后總報(bào)錯(cuò)，為了配置全局時(shí)間類型轉(zhuǎn)換，嘗試了如下處理方式。

注：本文基于Springboot2.x測試，如果無法生效可能是spring版本較低導(dǎo)致的。Spring Boot 基礎(chǔ)就不介紹了，推薦下這個(gè)實(shí)戰(zhàn)教程：https://github.com/javastacks/spring-boot-best-practice

PS：如果你的Controller中的LocalDate類型的參數(shù)啥注解（RequestParam、PathVariable等）都沒加，也是會出錯(cuò)的，因?yàn)槟J(rèn)情況下，解析這種參數(shù)是使用ModelAttributeMethodProcessor進(jìn)行處理，而這個(gè)處理器要通過反射實(shí)例化一個(gè)對象出來，然后再對對象中的各個(gè)參數(shù)進(jìn)行convert，但是LocalDate類沒有構(gòu)造函數(shù)，無法反射實(shí)例化因此會報(bào)錯(cuò)?。。?/strong>

完成目標(biāo)

• 請求入?yún)?String（指定格式）轉(zhuǎn) Date，支持get、post（content-type=application/json）
• 返回?cái)?shù)據(jù)為Date類型轉(zhuǎn)為指定的日期時(shí)間格式字符創(chuàng)
• 支持Java8 日期 API，如：LocalTime、localDate?和?LocalDateTime

GET請求及POST表單日期時(shí)間字符串格式轉(zhuǎn)換

這種情況要和時(shí)間作為Json字符串時(shí)區(qū)別對待，因?yàn)榍岸薺son轉(zhuǎn)后端pojo底層使用的是Json序列化Jackson工具（HttpMessgeConverter）；而時(shí)間字符串作為普通請求參數(shù)傳入時(shí)，轉(zhuǎn)換用的是Converter，兩者在處理方式上是有區(qū)別。

使用自定義參數(shù)轉(zhuǎn)換器（Converter）

?localDateTimeConverter()?{????????return?new?Converter()?{????????????@Override????????????public?LocalDateTime?convert(String?source)?{????????????????return?LocalDateTime.parse(source,?DateTimeFormatter.ofPattern("yyyy-MM-dd?HH:mm:ss"));????????????}????????};????}}點(diǎn)評：以上兩個(gè)bean會注入到spring mvc的參數(shù)解析器" linktype="text" imgurl="" imgdata="null" data-itemshowtype="0" tab="innerlink" data-linktype="2" hasload="1" wah-hotarea="click" style="margin: 0px; padding: 0px; outline: 0px; color: rgb(58, 58, 58); text-decoration: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); cursor: pointer; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important; visibility: visible;">實(shí)現(xiàn) org.springframework.core.convert.converter.Converter，自定義參數(shù)轉(zhuǎn)換器，如下：

?localDateTimeConverter()?{????????return?new?Converter()?{????????????@Override????????????public?LocalDateTime?convert(String?source)?{????????????????return?LocalDateTime.parse(source,?DateTimeFormatter.ofPattern("yyyy-MM-dd?HH:mm:ss"));????????????}????????};????}}點(diǎn)評：以上兩個(gè)bean會注入到spring mvc的參數(shù)解析器" linktype="text" imgurl="" imgdata="null" data-itemshowtype="0" tab="innerlink" data-linktype="2" hasload="1" wah-hotarea="click" style="margin: 0px; padding: 0px; outline: 0px; color: rgb(87, 107, 149); text-decoration: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); cursor: pointer; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important; visibility: visible;">@Configuration
public?class?DateConverterConfig?{
????@Bean
????public?Converter?localDateConverter()?{
???????return?new?Converter()?{
????????????@Override
????????????public?LocalDate?convert(String?source)?{
????????????????return?LocalDate.parse(source,?DateTimeFormatter.ofPattern("yyyy-MM-dd"));
????????????}
????????};
????}

????@Bean
????public?Converter?localDateTimeConverter()?{
????????return?new?Converter()?{
????????????@Override
????????????public?LocalDateTime?convert(String?source)?{
????????????????return?LocalDateTime.parse(source,?DateTimeFormatter.ofPattern("yyyy-MM-dd?HH:mm:ss"));
????????????}
????????};
????}
}

?localDateTimeConverter()?{????????return?new?Converter()?{????????????@Override????????????public?LocalDateTime?convert(String?source)?{????????????????return?LocalDateTime.parse(source,?DateTimeFormatter.ofPattern("yyyy-MM-dd?HH:mm:ss"));????????????}????????};????}}點(diǎn)評：以上兩個(gè)bean會注入到spring mvc的參數(shù)解析器" linktype="text" imgurl="" imgdata="null" data-itemshowtype="0" tab="innerlink" data-linktype="2" hasload="1" wah-hotarea="click" style="margin: 0px; padding: 0px; outline: 0px; color: rgb(58, 58, 58); text-decoration: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); cursor: pointer; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important; visibility: visible;">點(diǎn)評：以上兩個(gè)bean會注入到spring mvc的參數(shù)解析器（好像叫做ParameterConversionService），當(dāng)傳入的字符串要轉(zhuǎn)為LocalDateTime類時(shí)，spring會調(diào)用該Converter對這個(gè)入?yún)⑦M(jìn)行轉(zhuǎn)換。

注意：關(guān)于自定義的參數(shù)轉(zhuǎn)換器 Converter，這里我遇到了一個(gè)坑，我再這里詳細(xì)記錄下，本來我的想法是為了代碼精簡，將上面匿名內(nèi)部類的寫法精簡成lambda表達(dá)式的方式：

????@Bean
????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")
????public?Converter?localDateConverter()?{
????????return?source?->?LocalDate.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT));
????}

當(dāng)我再次啟動項(xiàng)目時(shí)卻出現(xiàn)了異常：

Caused?by:?java.lang.IllegalArgumentException:?Unable?to?determine?source?type??and?target?type??for?your?Converter?[com.example.demo126.config.MappingConverterAdapter$$Lambda$522/817994751];?does?the?class?parameterize?those?types?

百思不得其解，在查閱了資料才得知一二。最新 Spring 面試題整理好了，點(diǎn)擊Java面試庫小程序在線刷題。

web項(xiàng)目啟動注冊requestMappingHandlerAdapter的時(shí)候會初始化WebBindingInitializer

adapter.setWebBindingInitializer(getConfigurableWebBindingInitializer());

而ConfigurableWebBindingInitializer需要FormattingConversionService, 而FormattingConversionService會將所有的Converter添加進(jìn)來，添加的時(shí)候需要獲取泛型信息：

@Override
public?void?addFormatters(FormatterRegistry?registry)?{
????for?(Converter?converter?:?getBeansOfType(Converter.class))?{
???????registry.addConverter(converter);
????}
????for?(GenericConverter?converter?:?getBeansOfType(GenericConverter.class))?{
???????registry.addConverter(converter);
????}
????for?(Formatter?formatter?:?getBeansOfType(Formatter.class))?{
???????registry.addFormatter(formatter);
????}
}

添加Converter.class 一般是通過接口獲取兩個(gè)泛型的具體類型

public?ResolvableType?as(Class?type)?{
????if?(this?==?NONE)?{
??????return?NONE;
????}
????Class?resolved?=?resolve();
????if?(resolved?==?null?||?resolved?==?type)?{
??????return?this;
????}
????for?(ResolvableType?interfaceType?:?getInterfaces())?{
??????ResolvableType?interfaceAsType?=?interfaceType.as(type);
??????if?(interfaceAsType?!=?NONE)?{
????????return?interfaceAsType;
??????}
????}
????return?getSuperType().as(type);
}

Lambda表達(dá)式的接口是Converter，并不能得到具體的類型，在窺探了SpringMVC源碼后才得知原來如此，既然指導(dǎo)了原因，那解決辦法：

• 最簡單的方法就是不適用Lambda表達(dá)式，還是老老實(shí)實(shí)的使用匿名內(nèi)部類，這樣就不會存在上述問題

• 或者就是等requestMappingHandlerAdapterbean注冊完成之后再添加自己的converter就不會注冊到FormattingConversionService中

  @Bean
  @ConditionalOnBean(name?=?"requestMappingHandlerAdapter")
  public?Converter?localDateTimeConverter()?{
  ??return?source?->?LocalDateTime.parse(source,?DateTimeUtils.DEFAULT_FORMATTER);
  }
  

還可以對前端傳遞的string進(jìn)行正則匹配，如yyyy-MM-dd HH:mm:ss、yyyy-MM-dd、 HH:mm:ss等，進(jìn)行匹配。以適應(yīng)多種場景。

@Component
public?class?DateConverter?implements?Converter?{
????@Override
????public?Date?convert(String?value)?{
????????/**
?????????*?可對value進(jìn)行正則匹配，支持日期、時(shí)間等多種類型轉(zhuǎn)換
?????????*?這里我偷個(gè)懶，在匹配Date日期格式時(shí)直接使用了?hutool?為我們已經(jīng)寫好的解析工具類，這里就不重復(fù)造輪子了
?????????*?cn.hutool.core.date.DateUtil
?????????*?@param?value
?????????*?@return
?????????*/
????????return?DateUtil.parse(value.trim());
????}
}

注：這里我偷個(gè)懶，在匹配Date日期格式時(shí)直接使用了 hutool 為我們已經(jīng)寫好的解析工具類，這里就不重復(fù)造輪子了，下面的方法同樣使用了該工具類，想要在自己的項(xiàng)目中使用該工具類也很簡單，在項(xiàng)目pom文件中引入hutool的依賴就可以了，如下：

??cn.hutool
??hutool-all
??5.1.3

使用Spring注解

使用spring自帶注解@DateTimeFormat(pattern = "yyyy-MM-dd")，如下：

@DateTimeFormat(pattern?=?"yyyy-MM-dd")
private?Date?startDate;

如果使用了自定義參數(shù)轉(zhuǎn)化器，Spring會優(yōu)先使用該方式進(jìn)行處理，即Spring注解不生效。

最新 Spring 參考教程：https://www.javastack.cn/categories/Spring/

使用ControllerAdvice配合initBinder

@ControllerAdvice
public?class?GlobalExceptionHandler?{

????@InitBinder
????protected?void?initBinder(WebDataBinder?binder)?{
????????binder.registerCustomEditor(LocalDate.class,?new?PropertyEditorSupport()?{
????????????@Override
????????????public?void?setAsText(String?text)?throws?IllegalArgumentException?{
????????????????setValue(LocalDate.parse(text,?DateTimeFormatter.ofPattern("yyyy-MM-dd")));
????????????}
????????});
????????binder.registerCustomEditor(LocalDateTime.class,?new?PropertyEditorSupport()?{
????????????@Override
????????????public?void?setAsText(String?text)?throws?IllegalArgumentException?{
????????????????setValue(LocalDateTime.parse(text,?DateTimeFormatter.ofPattern("yyyy-MM-dd?HH:mm:ss")));
????????????}
????????});
????????binder.registerCustomEditor(LocalTime.class,?new?PropertyEditorSupport()?{
????????????@Override
????????????public?void?setAsText(String?text)?throws?IllegalArgumentException?{
????????????????setValue(LocalTime.parse(text,?DateTimeFormatter.ofPattern("HH:mm:ss")));
????????????}
????????});
????}
}

從名字就可以看出來，這是在controller做環(huán)切（這里面還可以全局異常捕獲），在參數(shù)進(jìn)入handler之前進(jìn)行轉(zhuǎn)換；轉(zhuǎn)換為我們相應(yīng)的對象。

JSON入?yún)⒓胺祷刂等痔幚?/h2>

請求類型為:post,content-type=application/json， 后臺用@RequestBody接收，默認(rèn)接收及返回值格式為:?yyyy-MM-dd HH:mm:ss

修改 application.yml 文件

Spring Boot 基礎(chǔ)就不介紹了，推薦下這個(gè)實(shí)戰(zhàn)教程：https://github.com/javastacks/spring-boot-best-practice

在application.propertities文件中增加如下內(nèi)容：

spring:
?jackson:
??date-format:?yyyy-MM-dd?HH:mm:ss
??time-zone:?GMT+8

• 支持（content-type=application/json）請求中格式為?yyyy-MM-dd HH:mm:ss的字符串，后臺用@RequestBody接收，及返回值date轉(zhuǎn)為yyyy-MM-dd HH:mm:ss格式string；
• 不支持（content-type=application/json）請求中yyyy-MM-dd等類型的字符串轉(zhuǎn)為date；
• 不支持java8日期api;

利用Jackson的JSON序列化和反序列化

@Configuration
public?class?JacksonConfig?{

????/**?默認(rèn)日期時(shí)間格式?*/
????public?static?final?String?DEFAULT_DATE_TIME_FORMAT?=?"yyyy-MM-dd?HH:mm:ss";
????/**?默認(rèn)日期格式?*/
????public?static?final?String?DEFAULT_DATE_FORMAT?=?"yyyy-MM-dd";
????/**?默認(rèn)時(shí)間格式?*/
????public?static?final?String?DEFAULT_TIME_FORMAT?=?"HH:mm:ss";

????@Bean
????public?MappingJackson2HttpMessageConverter?mappingJackson2HttpMessageConverter()?{
????????MappingJackson2HttpMessageConverter?converter?=?new?MappingJackson2HttpMessageConverter();
????????ObjectMapper?objectMapper?=?new?ObjectMapper();

????????//?忽略json字符串中不識別的屬性
????????objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES,?false);
????????//?忽略無法轉(zhuǎn)換的對象
????????objectMapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS,?false);
????????//?PrettyPrinter?格式化輸出
????????objectMapper.configure(SerializationFeature.INDENT_OUTPUT,?true);
????????//?NULL不參與序列化
????????objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);

????????//?指定時(shí)區(qū)
????????objectMapper.setTimeZone(TimeZone.getTimeZone("GMT+8:00"));
????????//?日期類型字符串處理
????????objectMapper.setDateFormat(new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT));

????????//?java8日期日期處理
????????JavaTimeModule?javaTimeModule?=?new?JavaTimeModule();
????????javaTimeModule.addSerializer(LocalDateTime.class,?new?LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));
????????javaTimeModule.addSerializer(LocalDate.class,?new?LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));
????????javaTimeModule.addSerializer(LocalTime.class,?new?LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));
????????javaTimeModule.addDeserializer(LocalDateTime.class,?new?LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));
????????javaTimeModule.addDeserializer(LocalDate.class,?new?LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));
????????javaTimeModule.addDeserializer(LocalTime.class,?new?LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));
????????objectMapper.registerModule(javaTimeModule);

????????converter.setObjectMapper(objectMapper);
????????return?converter;
????}
}

總結(jié)：

• 支持（content-type=application/json）請求中格式為yyyy-MM-dd HH:mm:ss的字符串，后臺用@RequestBody接收，及返回值Date轉(zhuǎn)為yyyy-MM-dd HH:mm:ss格式String；
• 支持java8日期api；
• 不支持（content-type=application/json）請求中yyyy-MM-dd等類型的字符串轉(zhuǎn)為Date；

以上兩種方式為JSON入?yún)⒌娜只幚?，推薦使用方式二，尤其適合大型項(xiàng)目在基礎(chǔ)包中全局設(shè)置。

JSON入?yún)⒓胺祷刂稻植坎町惢幚?/h2>

場景：假如全局日期時(shí)間處理格式為：yyyy-MM-dd HH:mm:ss，但是某個(gè)字段要求接收或返回日期yyyy-MM-dd。

方式一

使用springboot自帶的注解@JsonFormat(pattern = "yyyy-MM-dd")，如下所示：

@JsonFormat(pattern?=?"yyyy-MM-dd",?timezone="GMT+8")
private?Date?releaseDate;

點(diǎn)評：?springboot默認(rèn)提供，功能強(qiáng)大，滿足常見場景使用，并可指定時(shí)區(qū)。

方式二

?{????@Override????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException?{????????try?{????????????SimpleDateFormat?dateFormat?=?new?SimpleDateFormat("yyyy-MM-dd");????????????return?dateFormat.parse(jsonParser.getText());????????}?catch?(ParseException?e)?{????????????throw?new?RuntimeException(e);????????}????}}/**?*?使用方式?*/@JsonSerialize(using?=?DateJsonSerializer.class)@JsonDeserialize(using?=?DateJsonDeserializer.class)private?Date?releaseDate;日期時(shí)間格式化處理方式完整配置@Configurationpublic?class?DateHandlerConfig?{????/**?默認(rèn)日期時(shí)間格式?*/????public?static?final?String?DEFAULT_DATE_TIME_FORMAT?=?"yyyy-MM-dd?HH:mm:ss";????/**?默認(rèn)日期格式?*/????public?static?final?String?DEFAULT_DATE_FORMAT?=?"yyyy-MM-dd";????/**?默認(rèn)時(shí)間格式?*/????public?static?final?String?DEFAULT_TIME_FORMAT?=?"HH:mm:ss";????/**?????*?LocalDate轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?" conditionalonbean="?"requestMappingHandlerAdapter")" nbsp="?"requestMappingHandlerAdapter")????public?Converter?localDateConverter()?{????????return?source?->?LocalDate.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT));????}????/**?????*?LocalDateTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localDateTimeConverter()?{????????return?source?->?LocalDateTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT));????}????/**?????*?LocalTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localTimeConverter()?{????????return?source?->?LocalTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT));????}????/**?????*?Date轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?這里關(guān)于解析各種格式的日期格式采用了?hutool?的日期解析工具類?????*/????@Bean????public?Converter?dateConverter()?{????????return?new?Converter()?{????????????@Override????????????public?Date?convert(String?source)?{????????????????return?DateUtil.parse(source.trim());????????????}????????};????}????/**?????*?Json序列化和反序列化轉(zhuǎn)換器，用于轉(zhuǎn)換Post請求體中的json以及將我們的對象序列化為返回響應(yīng)的json?????*/????@Bean????public?ObjectMapper?objectMapper(){????????ObjectMapper?objectMapper?=?new?ObjectMapper();????????objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);????????objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);????????//LocalDateTime系列序列化和反序列化模塊，繼承自jsr310，我們在這里修改了日期格式????????JavaTimeModule?javaTimeModule?=?new?JavaTimeModule();????????javaTimeModule.addSerializer(LocalDateTime.class,new?LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addSerializer(LocalDate.class,new?LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addSerializer(LocalTime.class,new?LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDateTime.class,new?LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDate.class,new?LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addDeserializer(LocalTime.class,new?LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????//Date序列化和反序列化????????javaTimeModule.addSerializer(Date.class,?new?JsonSerializer<>()?{????????????@Override????????????public?void?serialize(Date?date,?JsonGenerator?jsonGenerator,?SerializerProvider?serializerProvider)?throws?IOException?{????????????????SimpleDateFormat?formatter?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?formattedDate?=?formatter.format(date);????????????????jsonGenerator.writeString(formattedDate);????????????}????????});????????javaTimeModule.addDeserializer(Date.class,?new?JsonDeserializer<>()?{????????????@Override????????????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException,?JsonProcessingException?{????????????????SimpleDateFormat?format?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?date?=?jsonParser.getText();????????????????try?{????????????????????return?format.parse(date);????????????????}?catch?(ParseException?e)?{????????????????????throw?new?RuntimeException(e);????????????????}????????????}????????});????????objectMapper.registerModule(javaTimeModule);????????return?objectMapper;????}}擴(kuò)充源碼：深入研究SpringMVC數(shù)據(jù)綁定過程接下來進(jìn)入debug模式，看看mvc是如何將我們r(jià)equest中的參數(shù)綁定到我們controller層方法入?yún)⒌?；寫一個(gè)簡單controller，打個(gè)斷點(diǎn)看看方法調(diào)用棧：????@GetMapping("/getDate")????public?LocalDateTime?getDate(@RequestParam?LocalDate?date,?????????????????????????????????@RequestParam?LocalDateTime?dateTime,?????????????????????????????????@RequestParam?Date?originalDate)?{????????System.out.println(date);????????System.out.println(dateTime);????????System.out.println(originalDate);????????return?LocalDateTime.now();????}調(diào)用接口以后，我們看下方法調(diào)用棧中一些關(guān)鍵方法：//進(jìn)入DispatcherServletdoService:942,?DispatcherServlet//處理請求doDispatch:1038,?DispatcherServlet//生成調(diào)用鏈（前處理、實(shí)際調(diào)用方法、后處理）handle:87,?AbstractHandlerMethodAdapter//反射獲取到實(shí)際調(diào)用方法，準(zhǔn)備開始調(diào)用invokeHandlerMethod:895,?RequestMappingHandlerAdapterinvokeAndHandle:102,?ServletInvocableHandlerMethod//這里是關(guān)鍵，參數(shù)從這里開始獲取到invokeForRequest:142,?InvocableHandlerMethoddoInvoke:215,?InvocableHandlerMethod//這個(gè)是Java?reflect調(diào)用，因此一定是在這之前獲取到的參數(shù)invoke:566,?Method根據(jù)上述分析，""" linktype="text" imgurl="" imgdata="null" data-itemshowtype="0" tab="innerlink" data-linktype="2" wah-hotarea="click" hasload="1" style="margin: 0px; padding: 0px; outline: 0px; color: rgb(58, 58, 58); text-decoration: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); cursor: pointer; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important;">自定義日期序列化與反序列化，如下所示：

?{????@Override????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException?{????????try?{????????????SimpleDateFormat?dateFormat?=?new?SimpleDateFormat("yyyy-MM-dd");????????????return?dateFormat.parse(jsonParser.getText());????????}?catch?(ParseException?e)?{????????????throw?new?RuntimeException(e);????????}????}}/**?*?使用方式?*/@JsonSerialize(using?=?DateJsonSerializer.class)@JsonDeserialize(using?=?DateJsonDeserializer.class)private?Date?releaseDate;日期時(shí)間格式化處理方式完整配置@Configurationpublic?class?DateHandlerConfig?{????/**?默認(rèn)日期時(shí)間格式?*/????public?static?final?String?DEFAULT_DATE_TIME_FORMAT?=?"yyyy-MM-dd?HH:mm:ss";????/**?默認(rèn)日期格式?*/????public?static?final?String?DEFAULT_DATE_FORMAT?=?"yyyy-MM-dd";????/**?默認(rèn)時(shí)間格式?*/????public?static?final?String?DEFAULT_TIME_FORMAT?=?"HH:mm:ss";????/**?????*?LocalDate轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?" conditionalonbean="?"requestMappingHandlerAdapter")" nbsp="?"requestMappingHandlerAdapter")????public?Converter?localDateConverter()?{????????return?source?->?LocalDate.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT));????}????/**?????*?LocalDateTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localDateTimeConverter()?{????????return?source?->?LocalDateTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT));????}????/**?????*?LocalTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localTimeConverter()?{????????return?source?->?LocalTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT));????}????/**?????*?Date轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?這里關(guān)于解析各種格式的日期格式采用了?hutool?的日期解析工具類?????*/????@Bean????public?Converter?dateConverter()?{????????return?new?Converter()?{????????????@Override????????????public?Date?convert(String?source)?{????????????????return?DateUtil.parse(source.trim());????????????}????????};????}????/**?????*?Json序列化和反序列化轉(zhuǎn)換器，用于轉(zhuǎn)換Post請求體中的json以及將我們的對象序列化為返回響應(yīng)的json?????*/????@Bean????public?ObjectMapper?objectMapper(){????????ObjectMapper?objectMapper?=?new?ObjectMapper();????????objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);????????objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);????????//LocalDateTime系列序列化和反序列化模塊，繼承自jsr310，我們在這里修改了日期格式????????JavaTimeModule?javaTimeModule?=?new?JavaTimeModule();????????javaTimeModule.addSerializer(LocalDateTime.class,new?LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addSerializer(LocalDate.class,new?LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addSerializer(LocalTime.class,new?LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDateTime.class,new?LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDate.class,new?LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addDeserializer(LocalTime.class,new?LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????//Date序列化和反序列化????????javaTimeModule.addSerializer(Date.class,?new?JsonSerializer<>()?{????????????@Override????????????public?void?serialize(Date?date,?JsonGenerator?jsonGenerator,?SerializerProvider?serializerProvider)?throws?IOException?{????????????????SimpleDateFormat?formatter?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?formattedDate?=?formatter.format(date);????????????????jsonGenerator.writeString(formattedDate);????????????}????????});????????javaTimeModule.addDeserializer(Date.class,?new?JsonDeserializer<>()?{????????????@Override????????????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException,?JsonProcessingException?{????????????????SimpleDateFormat?format?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?date?=?jsonParser.getText();????????????????try?{????????????????????return?format.parse(date);????????????????}?catch?(ParseException?e)?{????????????????????throw?new?RuntimeException(e);????????????????}????????????}????????});????????objectMapper.registerModule(javaTimeModule);????????return?objectMapper;????}}擴(kuò)充源碼：深入研究SpringMVC數(shù)據(jù)綁定過程接下來進(jìn)入debug模式，看看mvc是如何將我們r(jià)equest中的參數(shù)綁定到我們controller層方法入?yún)⒌?；寫一個(gè)簡單controller，打個(gè)斷點(diǎn)看看方法調(diào)用棧：????@GetMapping("/getDate")????public?LocalDateTime?getDate(@RequestParam?LocalDate?date,?????????????????????????????????@RequestParam?LocalDateTime?dateTime,?????????????????????????????????@RequestParam?Date?originalDate)?{????????System.out.println(date);????????System.out.println(dateTime);????????System.out.println(originalDate);????????return?LocalDateTime.now();????}調(diào)用接口以后，我們看下方法調(diào)用棧中一些關(guān)鍵方法：//進(jìn)入DispatcherServletdoService:942,?DispatcherServlet//處理請求doDispatch:1038,?DispatcherServlet//生成調(diào)用鏈（前處理、實(shí)際調(diào)用方法、后處理）handle:87,?AbstractHandlerMethodAdapter//反射獲取到實(shí)際調(diào)用方法，準(zhǔn)備開始調(diào)用invokeHandlerMethod:895,?RequestMappingHandlerAdapterinvokeAndHandle:102,?ServletInvocableHandlerMethod//這里是關(guān)鍵，參數(shù)從這里開始獲取到invokeForRequest:142,?InvocableHandlerMethoddoInvoke:215,?InvocableHandlerMethod//這個(gè)是Java?reflect調(diào)用，因此一定是在這之前獲取到的參數(shù)invoke:566,?Method根據(jù)上述分析，""" linktype="text" imgurl="" imgdata="null" data-itemshowtype="0" tab="innerlink" data-linktype="2" wah-hotarea="click" hasload="1" style="margin: 0px; padding: 0px; outline: 0px; color: rgb(87, 107, 149); text-decoration: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); cursor: pointer; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important;">/**
?*?日期序列化
?*/
public?class?DateJsonSerializer?extends?JsonSerializer?{
????@Override
????public?void?serialize(Date?date,?JsonGenerator?jsonGenerator,?SerializerProvider?serializerProvider)?throws?IOException?{
????????SimpleDateFormat?dateFormat?=?new?SimpleDateFormat("yyyy-MM-dd");
????????jsonGenerator.writeString(dateFormat.format(date));
????}
}

/**
?*?日期反序列化
?*/
public?class?DateJsonDeserializer?extends?JsonDeserializer?{
????@Override
????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException?{
????????try?{
????????????SimpleDateFormat?dateFormat?=?new?SimpleDateFormat("yyyy-MM-dd");
????????????return?dateFormat.parse(jsonParser.getText());
????????}?catch?(ParseException?e)?{
????????????throw?new?RuntimeException(e);
????????}
????}
}

/**
?*?使用方式
?*/
@JsonSerialize(using?=?DateJsonSerializer.class)
@JsonDeserialize(using?=?DateJsonDeserializer.class)
private?Date?releaseDate;

日期時(shí)間格式化處理方式完整配置

?{????@Override????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException?{????????try?{????????????SimpleDateFormat?dateFormat?=?new?SimpleDateFormat("yyyy-MM-dd");????????????return?dateFormat.parse(jsonParser.getText());????????}?catch?(ParseException?e)?{????????????throw?new?RuntimeException(e);????????}????}}/**?*?使用方式?*/@JsonSerialize(using?=?DateJsonSerializer.class)@JsonDeserialize(using?=?DateJsonDeserializer.class)private?Date?releaseDate;日期時(shí)間格式化處理方式完整配置@Configurationpublic?class?DateHandlerConfig?{????/**?默認(rèn)日期時(shí)間格式?*/????public?static?final?String?DEFAULT_DATE_TIME_FORMAT?=?"yyyy-MM-dd?HH:mm:ss";????/**?默認(rèn)日期格式?*/????public?static?final?String?DEFAULT_DATE_FORMAT?=?"yyyy-MM-dd";????/**?默認(rèn)時(shí)間格式?*/????public?static?final?String?DEFAULT_TIME_FORMAT?=?"HH:mm:ss";????/**?????*?LocalDate轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?" conditionalonbean="?"requestMappingHandlerAdapter")" nbsp="?"requestMappingHandlerAdapter")????public?Converter?localDateConverter()?{????????return?source?->?LocalDate.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT));????}????/**?????*?LocalDateTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localDateTimeConverter()?{????????return?source?->?LocalDateTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT));????}????/**?????*?LocalTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localTimeConverter()?{????????return?source?->?LocalTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT));????}????/**?????*?Date轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?這里關(guān)于解析各種格式的日期格式采用了?hutool?的日期解析工具類?????*/????@Bean????public?Converter?dateConverter()?{????????return?new?Converter()?{????????????@Override????????????public?Date?convert(String?source)?{????????????????return?DateUtil.parse(source.trim());????????????}????????};????}????/**?????*?Json序列化和反序列化轉(zhuǎn)換器，用于轉(zhuǎn)換Post請求體中的json以及將我們的對象序列化為返回響應(yīng)的json?????*/????@Bean????public?ObjectMapper?objectMapper(){????????ObjectMapper?objectMapper?=?new?ObjectMapper();????????objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);????????objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);????????//LocalDateTime系列序列化和反序列化模塊，繼承自jsr310，我們在這里修改了日期格式????????JavaTimeModule?javaTimeModule?=?new?JavaTimeModule();????????javaTimeModule.addSerializer(LocalDateTime.class,new?LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addSerializer(LocalDate.class,new?LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addSerializer(LocalTime.class,new?LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDateTime.class,new?LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDate.class,new?LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addDeserializer(LocalTime.class,new?LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????//Date序列化和反序列化????????javaTimeModule.addSerializer(Date.class,?new?JsonSerializer<>()?{????????????@Override????????????public?void?serialize(Date?date,?JsonGenerator?jsonGenerator,?SerializerProvider?serializerProvider)?throws?IOException?{????????????????SimpleDateFormat?formatter?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?formattedDate?=?formatter.format(date);????????????????jsonGenerator.writeString(formattedDate);????????????}????????});????????javaTimeModule.addDeserializer(Date.class,?new?JsonDeserializer<>()?{????????????@Override????????????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException,?JsonProcessingException?{????????????????SimpleDateFormat?format?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?date?=?jsonParser.getText();????????????????try?{????????????????????return?format.parse(date);????????????????}?catch?(ParseException?e)?{????????????????????throw?new?RuntimeException(e);????????????????}????????????}????????});????????objectMapper.registerModule(javaTimeModule);????????return?objectMapper;????}}擴(kuò)充源碼：深入研究SpringMVC數(shù)據(jù)綁定過程接下來進(jìn)入debug模式，看看mvc是如何將我們r(jià)equest中的參數(shù)綁定到我們controller層方法入?yún)⒌?；寫一個(gè)簡單controller，打個(gè)斷點(diǎn)看看方法調(diào)用棧：????@GetMapping("/getDate")????public?LocalDateTime?getDate(@RequestParam?LocalDate?date,?????????????????????????????????@RequestParam?LocalDateTime?dateTime,?????????????????????????????????@RequestParam?Date?originalDate)?{????????System.out.println(date);????????System.out.println(dateTime);????????System.out.println(originalDate);????????return?LocalDateTime.now();????}調(diào)用接口以后，我們看下方法調(diào)用棧中一些關(guān)鍵方法：//進(jìn)入DispatcherServletdoService:942,?DispatcherServlet//處理請求doDispatch:1038,?DispatcherServlet//生成調(diào)用鏈（前處理、實(shí)際調(diào)用方法、后處理）handle:87,?AbstractHandlerMethodAdapter//反射獲取到實(shí)際調(diào)用方法，準(zhǔn)備開始調(diào)用invokeHandlerMethod:895,?RequestMappingHandlerAdapterinvokeAndHandle:102,?ServletInvocableHandlerMethod//這里是關(guān)鍵，參數(shù)從這里開始獲取到invokeForRequest:142,?InvocableHandlerMethoddoInvoke:215,?InvocableHandlerMethod//這個(gè)是Java?reflect調(diào)用，因此一定是在這之前獲取到的參數(shù)invoke:566,?Method根據(jù)上述分析，""" linktype="text" imgurl="" imgdata="null" data-itemshowtype="0" tab="innerlink" data-linktype="2" wah-hotarea="click" hasload="1" style="margin: 0px; padding: 0px; outline: 0px; color: rgb(87, 107, 149); text-decoration: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); cursor: pointer; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important;">@Configuration
public?class?DateHandlerConfig?{

????/**?默認(rèn)日期時(shí)間格式?*/
????public?static?final?String?DEFAULT_DATE_TIME_FORMAT?=?"yyyy-MM-dd?HH:mm:ss";
????/**?默認(rèn)日期格式?*/
????public?static?final?String?DEFAULT_DATE_FORMAT?=?"yyyy-MM-dd";
????/**?默認(rèn)時(shí)間格式?*/
????public?static?final?String?DEFAULT_TIME_FORMAT?=?"HH:mm:ss";

????/**
?????*?LocalDate轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)
?????*?`@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")`:?等requestMappingHandlerAdapter?bean注冊完成之后
?????*?再添加自己的`converter`就不會注冊到`FormattingConversionService`中
?????*/
????@Bean
????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")
????public?Converter?localDateConverter()?{
????????return?source?->?LocalDate.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT));
????}

????/**
?????*?LocalDateTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)
?????*/
????@Bean
????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")
????public?Converter?localDateTimeConverter()?{
????????return?source?->?LocalDateTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT));
????}

????/**
?????*?LocalTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)
?????*/
????@Bean
????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")
????public?Converter?localTimeConverter()?{
????????return?source?->?LocalTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT));
????}

????/**
?????*?Date轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)
?????*?這里關(guān)于解析各種格式的日期格式采用了?hutool?的日期解析工具類
?????*/
????@Bean
????public?Converter?dateConverter()?{
????????return?new?Converter()?{
????????????@Override
????????????public?Date?convert(String?source)?{
????????????????return?DateUtil.parse(source.trim());
????????????}
????????};
????}

????/**
?????*?Json序列化和反序列化轉(zhuǎn)換器，用于轉(zhuǎn)換Post請求體中的json以及將我們的對象序列化為返回響應(yīng)的json
?????*/
????@Bean
????public?ObjectMapper?objectMapper(){
????????ObjectMapper?objectMapper?=?new?ObjectMapper();
????????objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
????????objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);

????????//LocalDateTime系列序列化和反序列化模塊，繼承自jsr310，我們在這里修改了日期格式
????????JavaTimeModule?javaTimeModule?=?new?JavaTimeModule();
????????javaTimeModule.addSerializer(LocalDateTime.class,new?LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));
????????javaTimeModule.addSerializer(LocalDate.class,new?LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));
????????javaTimeModule.addSerializer(LocalTime.class,new?LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));
????????javaTimeModule.addDeserializer(LocalDateTime.class,new?LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));
????????javaTimeModule.addDeserializer(LocalDate.class,new?LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));
????????javaTimeModule.addDeserializer(LocalTime.class,new?LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));


????????//Date序列化和反序列化
????????javaTimeModule.addSerializer(Date.class,?new?JsonSerializer<>()?{
????????????@Override
????????????public?void?serialize(Date?date,?JsonGenerator?jsonGenerator,?SerializerProvider?serializerProvider)?throws?IOException?{
????????????????SimpleDateFormat?formatter?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);
????????????????String?formattedDate?=?formatter.format(date);
????????????????jsonGenerator.writeString(formattedDate);
????????????}
????????});
????????javaTimeModule.addDeserializer(Date.class,?new?JsonDeserializer<>()?{
????????????@Override
????????????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException,?JsonProcessingException?{
????????????????SimpleDateFormat?format?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);
????????????????String?date?=?jsonParser.getText();
????????????????try?{
????????????????????return?format.parse(date);
????????????????}?catch?(ParseException?e)?{
????????????????????throw?new?RuntimeException(e);
????????????????}
????????????}
????????});

????????objectMapper.registerModule(javaTimeModule);
????????return?objectMapper;
????}
}

擴(kuò)充源碼：深入研究SpringMVC數(shù)據(jù)綁定過程

?{????@Override????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException?{????????try?{????????????SimpleDateFormat?dateFormat?=?new?SimpleDateFormat("yyyy-MM-dd");????????????return?dateFormat.parse(jsonParser.getText());????????}?catch?(ParseException?e)?{????????????throw?new?RuntimeException(e);????????}????}}/**?*?使用方式?*/@JsonSerialize(using?=?DateJsonSerializer.class)@JsonDeserialize(using?=?DateJsonDeserializer.class)private?Date?releaseDate;日期時(shí)間格式化處理方式完整配置@Configurationpublic?class?DateHandlerConfig?{????/**?默認(rèn)日期時(shí)間格式?*/????public?static?final?String?DEFAULT_DATE_TIME_FORMAT?=?"yyyy-MM-dd?HH:mm:ss";????/**?默認(rèn)日期格式?*/????public?static?final?String?DEFAULT_DATE_FORMAT?=?"yyyy-MM-dd";????/**?默認(rèn)時(shí)間格式?*/????public?static?final?String?DEFAULT_TIME_FORMAT?=?"HH:mm:ss";????/**?????*?LocalDate轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?" conditionalonbean="?"requestMappingHandlerAdapter")" nbsp="?"requestMappingHandlerAdapter")????public?Converter?localDateConverter()?{????????return?source?->?LocalDate.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT));????}????/**?????*?LocalDateTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localDateTimeConverter()?{????????return?source?->?LocalDateTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT));????}????/**?????*?LocalTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localTimeConverter()?{????????return?source?->?LocalTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT));????}????/**?????*?Date轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?這里關(guān)于解析各種格式的日期格式采用了?hutool?的日期解析工具類?????*/????@Bean????public?Converter?dateConverter()?{????????return?new?Converter()?{????????????@Override????????????public?Date?convert(String?source)?{????????????????return?DateUtil.parse(source.trim());????????????}????????};????}????/**?????*?Json序列化和反序列化轉(zhuǎn)換器，用于轉(zhuǎn)換Post請求體中的json以及將我們的對象序列化為返回響應(yīng)的json?????*/????@Bean????public?ObjectMapper?objectMapper(){????????ObjectMapper?objectMapper?=?new?ObjectMapper();????????objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);????????objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);????????//LocalDateTime系列序列化和反序列化模塊，繼承自jsr310，我們在這里修改了日期格式????????JavaTimeModule?javaTimeModule?=?new?JavaTimeModule();????????javaTimeModule.addSerializer(LocalDateTime.class,new?LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addSerializer(LocalDate.class,new?LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addSerializer(LocalTime.class,new?LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDateTime.class,new?LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDate.class,new?LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addDeserializer(LocalTime.class,new?LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????//Date序列化和反序列化????????javaTimeModule.addSerializer(Date.class,?new?JsonSerializer<>()?{????????????@Override????????????public?void?serialize(Date?date,?JsonGenerator?jsonGenerator,?SerializerProvider?serializerProvider)?throws?IOException?{????????????????SimpleDateFormat?formatter?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?formattedDate?=?formatter.format(date);????????????????jsonGenerator.writeString(formattedDate);????????????}????????});????????javaTimeModule.addDeserializer(Date.class,?new?JsonDeserializer<>()?{????????????@Override????????????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException,?JsonProcessingException?{????????????????SimpleDateFormat?format?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?date?=?jsonParser.getText();????????????????try?{????????????????????return?format.parse(date);????????????????}?catch?(ParseException?e)?{????????????????????throw?new?RuntimeException(e);????????????????}????????????}????????});????????objectMapper.registerModule(javaTimeModule);????????return?objectMapper;????}}擴(kuò)充源碼：深入研究SpringMVC數(shù)據(jù)綁定過程接下來進(jìn)入debug模式，看看mvc是如何將我們r(jià)equest中的參數(shù)綁定到我們controller層方法入?yún)⒌模粚懸粋€(gè)簡單controller，打個(gè)斷點(diǎn)看看方法調(diào)用棧：????@GetMapping("/getDate")????public?LocalDateTime?getDate(@RequestParam?LocalDate?date,?????????????????????????????????@RequestParam?LocalDateTime?dateTime,?????????????????????????????????@RequestParam?Date?originalDate)?{????????System.out.println(date);????????System.out.println(dateTime);????????System.out.println(originalDate);????????return?LocalDateTime.now();????}調(diào)用接口以后，我們看下方法調(diào)用棧中一些關(guān)鍵方法：//進(jìn)入DispatcherServletdoService:942,?DispatcherServlet//處理請求doDispatch:1038,?DispatcherServlet//生成調(diào)用鏈（前處理、實(shí)際調(diào)用方法、后處理）handle:87,?AbstractHandlerMethodAdapter//反射獲取到實(shí)際調(diào)用方法，準(zhǔn)備開始調(diào)用invokeHandlerMethod:895,?RequestMappingHandlerAdapterinvokeAndHandle:102,?ServletInvocableHandlerMethod//這里是關(guān)鍵，參數(shù)從這里開始獲取到invokeForRequest:142,?InvocableHandlerMethoddoInvoke:215,?InvocableHandlerMethod//這個(gè)是Java?reflect調(diào)用，因此一定是在這之前獲取到的參數(shù)invoke:566,?Method根據(jù)上述分析，""" linktype="text" imgurl="" imgdata="null" data-itemshowtype="0" tab="innerlink" data-linktype="2" wah-hotarea="click" hasload="1" style="margin: 0px; padding: 0px; outline: 0px; color: rgb(58, 58, 58); text-decoration: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); cursor: pointer; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important;">接下來進(jìn)入debug模式，看看mvc是如何將我們r(jià)equest中的參數(shù)綁定到我們controller層方法入?yún)⒌模?/a>

?{????@Override????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException?{????????try?{????????????SimpleDateFormat?dateFormat?=?new?SimpleDateFormat("yyyy-MM-dd");????????????return?dateFormat.parse(jsonParser.getText());????????}?catch?(ParseException?e)?{????????????throw?new?RuntimeException(e);????????}????}}/**?*?使用方式?*/@JsonSerialize(using?=?DateJsonSerializer.class)@JsonDeserialize(using?=?DateJsonDeserializer.class)private?Date?releaseDate;日期時(shí)間格式化處理方式完整配置@Configurationpublic?class?DateHandlerConfig?{????/**?默認(rèn)日期時(shí)間格式?*/????public?static?final?String?DEFAULT_DATE_TIME_FORMAT?=?"yyyy-MM-dd?HH:mm:ss";????/**?默認(rèn)日期格式?*/????public?static?final?String?DEFAULT_DATE_FORMAT?=?"yyyy-MM-dd";????/**?默認(rèn)時(shí)間格式?*/????public?static?final?String?DEFAULT_TIME_FORMAT?=?"HH:mm:ss";????/**?????*?LocalDate轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?" conditionalonbean="?"requestMappingHandlerAdapter")" nbsp="?"requestMappingHandlerAdapter")????public?Converter?localDateConverter()?{????????return?source?->?LocalDate.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT));????}????/**?????*?LocalDateTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localDateTimeConverter()?{????????return?source?->?LocalDateTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT));????}????/**?????*?LocalTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localTimeConverter()?{????????return?source?->?LocalTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT));????}????/**?????*?Date轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?這里關(guān)于解析各種格式的日期格式采用了?hutool?的日期解析工具類?????*/????@Bean????public?Converter?dateConverter()?{????????return?new?Converter()?{????????????@Override????????????public?Date?convert(String?source)?{????????????????return?DateUtil.parse(source.trim());????????????}????????};????}????/**?????*?Json序列化和反序列化轉(zhuǎn)換器，用于轉(zhuǎn)換Post請求體中的json以及將我們的對象序列化為返回響應(yīng)的json?????*/????@Bean????public?ObjectMapper?objectMapper(){????????ObjectMapper?objectMapper?=?new?ObjectMapper();????????objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);????????objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);????????//LocalDateTime系列序列化和反序列化模塊，繼承自jsr310，我們在這里修改了日期格式????????JavaTimeModule?javaTimeModule?=?new?JavaTimeModule();????????javaTimeModule.addSerializer(LocalDateTime.class,new?LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addSerializer(LocalDate.class,new?LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addSerializer(LocalTime.class,new?LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDateTime.class,new?LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDate.class,new?LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addDeserializer(LocalTime.class,new?LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????//Date序列化和反序列化????????javaTimeModule.addSerializer(Date.class,?new?JsonSerializer<>()?{????????????@Override????????????public?void?serialize(Date?date,?JsonGenerator?jsonGenerator,?SerializerProvider?serializerProvider)?throws?IOException?{????????????????SimpleDateFormat?formatter?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?formattedDate?=?formatter.format(date);????????????????jsonGenerator.writeString(formattedDate);????????????}????????});????????javaTimeModule.addDeserializer(Date.class,?new?JsonDeserializer<>()?{????????????@Override????????????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException,?JsonProcessingException?{????????????????SimpleDateFormat?format?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?date?=?jsonParser.getText();????????????????try?{????????????????????return?format.parse(date);????????????????}?catch?(ParseException?e)?{????????????????????throw?new?RuntimeException(e);????????????????}????????????}????????});????????objectMapper.registerModule(javaTimeModule);????????return?objectMapper;????}}擴(kuò)充源碼：深入研究SpringMVC數(shù)據(jù)綁定過程接下來進(jìn)入debug模式，看看mvc是如何將我們r(jià)equest中的參數(shù)綁定到我們controller層方法入?yún)⒌模粚懸粋€(gè)簡單controller，打個(gè)斷點(diǎn)看看方法調(diào)用棧：????@GetMapping("/getDate")????public?LocalDateTime?getDate(@RequestParam?LocalDate?date,?????????????????????????????????@RequestParam?LocalDateTime?dateTime,?????????????????????????????????@RequestParam?Date?originalDate)?{????????System.out.println(date);????????System.out.println(dateTime);????????System.out.println(originalDate);????????return?LocalDateTime.now();????}調(diào)用接口以后，我們看下方法調(diào)用棧中一些關(guān)鍵方法：//進(jìn)入DispatcherServletdoService:942,?DispatcherServlet//處理請求doDispatch:1038,?DispatcherServlet//生成調(diào)用鏈（前處理、實(shí)際調(diào)用方法、后處理）handle:87,?AbstractHandlerMethodAdapter//反射獲取到實(shí)際調(diào)用方法，準(zhǔn)備開始調(diào)用invokeHandlerMethod:895,?RequestMappingHandlerAdapterinvokeAndHandle:102,?ServletInvocableHandlerMethod//這里是關(guān)鍵，參數(shù)從這里開始獲取到invokeForRequest:142,?InvocableHandlerMethoddoInvoke:215,?InvocableHandlerMethod//這個(gè)是Java?reflect調(diào)用，因此一定是在這之前獲取到的參數(shù)invoke:566,?Method根據(jù)上述分析，""" linktype="text" imgurl="" imgdata="null" data-itemshowtype="0" tab="innerlink" data-linktype="2" wah-hotarea="click" hasload="1" style="margin: 0px; padding: 0px; outline: 0px; color: rgb(58, 58, 58); text-decoration: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); cursor: pointer; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important;">寫一個(gè)簡單controller，打個(gè)斷點(diǎn)看看方法調(diào)用棧：

?{????@Override????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException?{????????try?{????????????SimpleDateFormat?dateFormat?=?new?SimpleDateFormat("yyyy-MM-dd");????????????return?dateFormat.parse(jsonParser.getText());????????}?catch?(ParseException?e)?{????????????throw?new?RuntimeException(e);????????}????}}/**?*?使用方式?*/@JsonSerialize(using?=?DateJsonSerializer.class)@JsonDeserialize(using?=?DateJsonDeserializer.class)private?Date?releaseDate;日期時(shí)間格式化處理方式完整配置@Configurationpublic?class?DateHandlerConfig?{????/**?默認(rèn)日期時(shí)間格式?*/????public?static?final?String?DEFAULT_DATE_TIME_FORMAT?=?"yyyy-MM-dd?HH:mm:ss";????/**?默認(rèn)日期格式?*/????public?static?final?String?DEFAULT_DATE_FORMAT?=?"yyyy-MM-dd";????/**?默認(rèn)時(shí)間格式?*/????public?static?final?String?DEFAULT_TIME_FORMAT?=?"HH:mm:ss";????/**?????*?LocalDate轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?" conditionalonbean="?"requestMappingHandlerAdapter")" nbsp="?"requestMappingHandlerAdapter")????public?Converter?localDateConverter()?{????????return?source?->?LocalDate.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT));????}????/**?????*?LocalDateTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localDateTimeConverter()?{????????return?source?->?LocalDateTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT));????}????/**?????*?LocalTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localTimeConverter()?{????????return?source?->?LocalTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT));????}????/**?????*?Date轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?這里關(guān)于解析各種格式的日期格式采用了?hutool?的日期解析工具類?????*/????@Bean????public?Converter?dateConverter()?{????????return?new?Converter()?{????????????@Override????????????public?Date?convert(String?source)?{????????????????return?DateUtil.parse(source.trim());????????????}????????};????}????/**?????*?Json序列化和反序列化轉(zhuǎn)換器，用于轉(zhuǎn)換Post請求體中的json以及將我們的對象序列化為返回響應(yīng)的json?????*/????@Bean????public?ObjectMapper?objectMapper(){????????ObjectMapper?objectMapper?=?new?ObjectMapper();????????objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);????????objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);????????//LocalDateTime系列序列化和反序列化模塊，繼承自jsr310，我們在這里修改了日期格式????????JavaTimeModule?javaTimeModule?=?new?JavaTimeModule();????????javaTimeModule.addSerializer(LocalDateTime.class,new?LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addSerializer(LocalDate.class,new?LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addSerializer(LocalTime.class,new?LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDateTime.class,new?LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDate.class,new?LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addDeserializer(LocalTime.class,new?LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????//Date序列化和反序列化????????javaTimeModule.addSerializer(Date.class,?new?JsonSerializer<>()?{????????????@Override????????????public?void?serialize(Date?date,?JsonGenerator?jsonGenerator,?SerializerProvider?serializerProvider)?throws?IOException?{????????????????SimpleDateFormat?formatter?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?formattedDate?=?formatter.format(date);????????????????jsonGenerator.writeString(formattedDate);????????????}????????});????????javaTimeModule.addDeserializer(Date.class,?new?JsonDeserializer<>()?{????????????@Override????????????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException,?JsonProcessingException?{????????????????SimpleDateFormat?format?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?date?=?jsonParser.getText();????????????????try?{????????????????????return?format.parse(date);????????????????}?catch?(ParseException?e)?{????????????????????throw?new?RuntimeException(e);????????????????}????????????}????????});????????objectMapper.registerModule(javaTimeModule);????????return?objectMapper;????}}擴(kuò)充源碼：深入研究SpringMVC數(shù)據(jù)綁定過程接下來進(jìn)入debug模式，看看mvc是如何將我們r(jià)equest中的參數(shù)綁定到我們controller層方法入?yún)⒌?；寫一個(gè)簡單controller，打個(gè)斷點(diǎn)看看方法調(diào)用棧：????@GetMapping("/getDate")????public?LocalDateTime?getDate(@RequestParam?LocalDate?date,?????????????????????????????????@RequestParam?LocalDateTime?dateTime,?????????????????????????????????@RequestParam?Date?originalDate)?{????????System.out.println(date);????????System.out.println(dateTime);????????System.out.println(originalDate);????????return?LocalDateTime.now();????}調(diào)用接口以后，我們看下方法調(diào)用棧中一些關(guān)鍵方法：//進(jìn)入DispatcherServletdoService:942,?DispatcherServlet//處理請求doDispatch:1038,?DispatcherServlet//生成調(diào)用鏈（前處理、實(shí)際調(diào)用方法、后處理）handle:87,?AbstractHandlerMethodAdapter//反射獲取到實(shí)際調(diào)用方法，準(zhǔn)備開始調(diào)用invokeHandlerMethod:895,?RequestMappingHandlerAdapterinvokeAndHandle:102,?ServletInvocableHandlerMethod//這里是關(guān)鍵，參數(shù)從這里開始獲取到invokeForRequest:142,?InvocableHandlerMethoddoInvoke:215,?InvocableHandlerMethod//這個(gè)是Java?reflect調(diào)用，因此一定是在這之前獲取到的參數(shù)invoke:566,?Method根據(jù)上述分析，""" linktype="text" imgurl="" imgdata="null" data-itemshowtype="0" tab="innerlink" data-linktype="2" wah-hotarea="click" hasload="1" style="margin: 0px; padding: 0px; outline: 0px; color: rgb(87, 107, 149); text-decoration: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); cursor: pointer; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important;">????@GetMapping("/getDate")
????public?LocalDateTime?getDate(@RequestParam?LocalDate?date,
?????????????????????????????????@RequestParam?LocalDateTime?dateTime,
?????????????????????????????????@RequestParam?Date?originalDate)?{
????????System.out.println(date);
????????System.out.println(dateTime);
????????System.out.println(originalDate);
????????return?LocalDateTime.now();
????}

?{????@Override????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException?{????????try?{????????????SimpleDateFormat?dateFormat?=?new?SimpleDateFormat("yyyy-MM-dd");????????????return?dateFormat.parse(jsonParser.getText());????????}?catch?(ParseException?e)?{????????????throw?new?RuntimeException(e);????????}????}}/**?*?使用方式?*/@JsonSerialize(using?=?DateJsonSerializer.class)@JsonDeserialize(using?=?DateJsonDeserializer.class)private?Date?releaseDate;日期時(shí)間格式化處理方式完整配置@Configurationpublic?class?DateHandlerConfig?{????/**?默認(rèn)日期時(shí)間格式?*/????public?static?final?String?DEFAULT_DATE_TIME_FORMAT?=?"yyyy-MM-dd?HH:mm:ss";????/**?默認(rèn)日期格式?*/????public?static?final?String?DEFAULT_DATE_FORMAT?=?"yyyy-MM-dd";????/**?默認(rèn)時(shí)間格式?*/????public?static?final?String?DEFAULT_TIME_FORMAT?=?"HH:mm:ss";????/**?????*?LocalDate轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?" conditionalonbean="?"requestMappingHandlerAdapter")" nbsp="?"requestMappingHandlerAdapter")????public?Converter?localDateConverter()?{????????return?source?->?LocalDate.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT));????}????/**?????*?LocalDateTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localDateTimeConverter()?{????????return?source?->?LocalDateTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT));????}????/**?????*?LocalTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localTimeConverter()?{????????return?source?->?LocalTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT));????}????/**?????*?Date轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?這里關(guān)于解析各種格式的日期格式采用了?hutool?的日期解析工具類?????*/????@Bean????public?Converter?dateConverter()?{????????return?new?Converter()?{????????????@Override????????????public?Date?convert(String?source)?{????????????????return?DateUtil.parse(source.trim());????????????}????????};????}????/**?????*?Json序列化和反序列化轉(zhuǎn)換器，用于轉(zhuǎn)換Post請求體中的json以及將我們的對象序列化為返回響應(yīng)的json?????*/????@Bean????public?ObjectMapper?objectMapper(){????????ObjectMapper?objectMapper?=?new?ObjectMapper();????????objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);????????objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);????????//LocalDateTime系列序列化和反序列化模塊，繼承自jsr310，我們在這里修改了日期格式????????JavaTimeModule?javaTimeModule?=?new?JavaTimeModule();????????javaTimeModule.addSerializer(LocalDateTime.class,new?LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addSerializer(LocalDate.class,new?LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addSerializer(LocalTime.class,new?LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDateTime.class,new?LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDate.class,new?LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addDeserializer(LocalTime.class,new?LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????//Date序列化和反序列化????????javaTimeModule.addSerializer(Date.class,?new?JsonSerializer<>()?{????????????@Override????????????public?void?serialize(Date?date,?JsonGenerator?jsonGenerator,?SerializerProvider?serializerProvider)?throws?IOException?{????????????????SimpleDateFormat?formatter?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?formattedDate?=?formatter.format(date);????????????????jsonGenerator.writeString(formattedDate);????????????}????????});????????javaTimeModule.addDeserializer(Date.class,?new?JsonDeserializer<>()?{????????????@Override????????????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException,?JsonProcessingException?{????????????????SimpleDateFormat?format?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?date?=?jsonParser.getText();????????????????try?{????????????????????return?format.parse(date);????????????????}?catch?(ParseException?e)?{????????????????????throw?new?RuntimeException(e);????????????????}????????????}????????});????????objectMapper.registerModule(javaTimeModule);????????return?objectMapper;????}}擴(kuò)充源碼：深入研究SpringMVC數(shù)據(jù)綁定過程接下來進(jìn)入debug模式，看看mvc是如何將我們r(jià)equest中的參數(shù)綁定到我們controller層方法入?yún)⒌?；寫一個(gè)簡單controller，打個(gè)斷點(diǎn)看看方法調(diào)用棧：????@GetMapping("/getDate")????public?LocalDateTime?getDate(@RequestParam?LocalDate?date,?????????????????????????????????@RequestParam?LocalDateTime?dateTime,?????????????????????????????????@RequestParam?Date?originalDate)?{????????System.out.println(date);????????System.out.println(dateTime);????????System.out.println(originalDate);????????return?LocalDateTime.now();????}調(diào)用接口以后，我們看下方法調(diào)用棧中一些關(guān)鍵方法：//進(jìn)入DispatcherServletdoService:942,?DispatcherServlet//處理請求doDispatch:1038,?DispatcherServlet//生成調(diào)用鏈（前處理、實(shí)際調(diào)用方法、后處理）handle:87,?AbstractHandlerMethodAdapter//反射獲取到實(shí)際調(diào)用方法，準(zhǔn)備開始調(diào)用invokeHandlerMethod:895,?RequestMappingHandlerAdapterinvokeAndHandle:102,?ServletInvocableHandlerMethod//這里是關(guān)鍵，參數(shù)從這里開始獲取到invokeForRequest:142,?InvocableHandlerMethoddoInvoke:215,?InvocableHandlerMethod//這個(gè)是Java?reflect調(diào)用，因此一定是在這之前獲取到的參數(shù)invoke:566,?Method根據(jù)上述分析，""" linktype="text" imgurl="" imgdata="null" data-itemshowtype="0" tab="innerlink" data-linktype="2" wah-hotarea="click" hasload="1" style="margin: 0px; padding: 0px; outline: 0px; color: rgb(58, 58, 58); text-decoration: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); cursor: pointer; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important;">調(diào)用接口以后，我們看下方法調(diào)用棧中一些關(guān)鍵方法：

?{????@Override????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException?{????????try?{????????????SimpleDateFormat?dateFormat?=?new?SimpleDateFormat("yyyy-MM-dd");????????????return?dateFormat.parse(jsonParser.getText());????????}?catch?(ParseException?e)?{????????????throw?new?RuntimeException(e);????????}????}}/**?*?使用方式?*/@JsonSerialize(using?=?DateJsonSerializer.class)@JsonDeserialize(using?=?DateJsonDeserializer.class)private?Date?releaseDate;日期時(shí)間格式化處理方式完整配置@Configurationpublic?class?DateHandlerConfig?{????/**?默認(rèn)日期時(shí)間格式?*/????public?static?final?String?DEFAULT_DATE_TIME_FORMAT?=?"yyyy-MM-dd?HH:mm:ss";????/**?默認(rèn)日期格式?*/????public?static?final?String?DEFAULT_DATE_FORMAT?=?"yyyy-MM-dd";????/**?默認(rèn)時(shí)間格式?*/????public?static?final?String?DEFAULT_TIME_FORMAT?=?"HH:mm:ss";????/**?????*?LocalDate轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?" conditionalonbean="?"requestMappingHandlerAdapter")" nbsp="?"requestMappingHandlerAdapter")????public?Converter?localDateConverter()?{????????return?source?->?LocalDate.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT));????}????/**?????*?LocalDateTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localDateTimeConverter()?{????????return?source?->?LocalDateTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT));????}????/**?????*?LocalTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localTimeConverter()?{????????return?source?->?LocalTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT));????}????/**?????*?Date轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?這里關(guān)于解析各種格式的日期格式采用了?hutool?的日期解析工具類?????*/????@Bean????public?Converter?dateConverter()?{????????return?new?Converter()?{????????????@Override????????????public?Date?convert(String?source)?{????????????????return?DateUtil.parse(source.trim());????????????}????????};????}????/**?????*?Json序列化和反序列化轉(zhuǎn)換器，用于轉(zhuǎn)換Post請求體中的json以及將我們的對象序列化為返回響應(yīng)的json?????*/????@Bean????public?ObjectMapper?objectMapper(){????????ObjectMapper?objectMapper?=?new?ObjectMapper();????????objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);????????objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);????????//LocalDateTime系列序列化和反序列化模塊，繼承自jsr310，我們在這里修改了日期格式????????JavaTimeModule?javaTimeModule?=?new?JavaTimeModule();????????javaTimeModule.addSerializer(LocalDateTime.class,new?LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addSerializer(LocalDate.class,new?LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addSerializer(LocalTime.class,new?LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDateTime.class,new?LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDate.class,new?LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addDeserializer(LocalTime.class,new?LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????//Date序列化和反序列化????????javaTimeModule.addSerializer(Date.class,?new?JsonSerializer<>()?{????????????@Override????????????public?void?serialize(Date?date,?JsonGenerator?jsonGenerator,?SerializerProvider?serializerProvider)?throws?IOException?{????????????????SimpleDateFormat?formatter?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?formattedDate?=?formatter.format(date);????????????????jsonGenerator.writeString(formattedDate);????????????}????????});????????javaTimeModule.addDeserializer(Date.class,?new?JsonDeserializer<>()?{????????????@Override????????????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException,?JsonProcessingException?{????????????????SimpleDateFormat?format?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?date?=?jsonParser.getText();????????????????try?{????????????????????return?format.parse(date);????????????????}?catch?(ParseException?e)?{????????????????????throw?new?RuntimeException(e);????????????????}????????????}????????});????????objectMapper.registerModule(javaTimeModule);????????return?objectMapper;????}}擴(kuò)充源碼：深入研究SpringMVC數(shù)據(jù)綁定過程接下來進(jìn)入debug模式，看看mvc是如何將我們r(jià)equest中的參數(shù)綁定到我們controller層方法入?yún)⒌?；寫一個(gè)簡單controller，打個(gè)斷點(diǎn)看看方法調(diào)用棧：????@GetMapping("/getDate")????public?LocalDateTime?getDate(@RequestParam?LocalDate?date,?????????????????????????????????@RequestParam?LocalDateTime?dateTime,?????????????????????????????????@RequestParam?Date?originalDate)?{????????System.out.println(date);????????System.out.println(dateTime);????????System.out.println(originalDate);????????return?LocalDateTime.now();????}調(diào)用接口以后，我們看下方法調(diào)用棧中一些關(guān)鍵方法：//進(jìn)入DispatcherServletdoService:942,?DispatcherServlet//處理請求doDispatch:1038,?DispatcherServlet//生成調(diào)用鏈（前處理、實(shí)際調(diào)用方法、后處理）handle:87,?AbstractHandlerMethodAdapter//反射獲取到實(shí)際調(diào)用方法，準(zhǔn)備開始調(diào)用invokeHandlerMethod:895,?RequestMappingHandlerAdapterinvokeAndHandle:102,?ServletInvocableHandlerMethod//這里是關(guān)鍵，參數(shù)從這里開始獲取到invokeForRequest:142,?InvocableHandlerMethoddoInvoke:215,?InvocableHandlerMethod//這個(gè)是Java?reflect調(diào)用，因此一定是在這之前獲取到的參數(shù)invoke:566,?Method根據(jù)上述分析，""" linktype="text" imgurl="" imgdata="null" data-itemshowtype="0" tab="innerlink" data-linktype="2" wah-hotarea="click" hasload="1" style="margin: 0px; padding: 0px; outline: 0px; color: rgb(87, 107, 149); text-decoration: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); cursor: pointer; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important;">//進(jìn)入DispatcherServlet
doService:942,?DispatcherServlet
//處理請求
doDispatch:1038,?DispatcherServlet
//生成調(diào)用鏈（前處理、實(shí)際調(diào)用方法、后處理）
handle:87,?AbstractHandlerMethodAdapter
//反射獲取到實(shí)際調(diào)用方法，準(zhǔn)備開始調(diào)用
invokeHandlerMethod:895,?RequestMappingHandlerAdapter
invokeAndHandle:102,?ServletInvocableHandlerMethod
//這里是關(guān)鍵，參數(shù)從這里開始獲取到
invokeForRequest:142,?InvocableHandlerMethod
doInvoke:215,?InvocableHandlerMethod
//這個(gè)是Java?reflect調(diào)用，因此一定是在這之前獲取到的參數(shù)
invoke:566,?Method

?{????@Override????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException?{????????try?{????????????SimpleDateFormat?dateFormat?=?new?SimpleDateFormat("yyyy-MM-dd");????????????return?dateFormat.parse(jsonParser.getText());????????}?catch?(ParseException?e)?{????????????throw?new?RuntimeException(e);????????}????}}/**?*?使用方式?*/@JsonSerialize(using?=?DateJsonSerializer.class)@JsonDeserialize(using?=?DateJsonDeserializer.class)private?Date?releaseDate;日期時(shí)間格式化處理方式完整配置@Configurationpublic?class?DateHandlerConfig?{????/**?默認(rèn)日期時(shí)間格式?*/????public?static?final?String?DEFAULT_DATE_TIME_FORMAT?=?"yyyy-MM-dd?HH:mm:ss";????/**?默認(rèn)日期格式?*/????public?static?final?String?DEFAULT_DATE_FORMAT?=?"yyyy-MM-dd";????/**?默認(rèn)時(shí)間格式?*/????public?static?final?String?DEFAULT_TIME_FORMAT?=?"HH:mm:ss";????/**?????*?LocalDate轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?" conditionalonbean="?"requestMappingHandlerAdapter")" nbsp="?"requestMappingHandlerAdapter")????public?Converter?localDateConverter()?{????????return?source?->?LocalDate.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT));????}????/**?????*?LocalDateTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localDateTimeConverter()?{????????return?source?->?LocalDateTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT));????}????/**?????*?LocalTime轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*/????@Bean????@ConditionalOnBean(name?=?"requestMappingHandlerAdapter")????public?Converter?localTimeConverter()?{????????return?source?->?LocalTime.parse(source,?DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT));????}????/**?????*?Date轉(zhuǎn)換器，用于轉(zhuǎn)換RequestParam和PathVariable參數(shù)?????*?這里關(guān)于解析各種格式的日期格式采用了?hutool?的日期解析工具類?????*/????@Bean????public?Converter?dateConverter()?{????????return?new?Converter()?{????????????@Override????????????public?Date?convert(String?source)?{????????????????return?DateUtil.parse(source.trim());????????????}????????};????}????/**?????*?Json序列化和反序列化轉(zhuǎn)換器，用于轉(zhuǎn)換Post請求體中的json以及將我們的對象序列化為返回響應(yīng)的json?????*/????@Bean????public?ObjectMapper?objectMapper(){????????ObjectMapper?objectMapper?=?new?ObjectMapper();????????objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);????????objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);????????//LocalDateTime系列序列化和反序列化模塊，繼承自jsr310，我們在這里修改了日期格式????????JavaTimeModule?javaTimeModule?=?new?JavaTimeModule();????????javaTimeModule.addSerializer(LocalDateTime.class,new?LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addSerializer(LocalDate.class,new?LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addSerializer(LocalTime.class,new?LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDateTime.class,new?LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)));????????javaTimeModule.addDeserializer(LocalDate.class,new?LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)));????????javaTimeModule.addDeserializer(LocalTime.class,new?LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));????????//Date序列化和反序列化????????javaTimeModule.addSerializer(Date.class,?new?JsonSerializer<>()?{????????????@Override????????????public?void?serialize(Date?date,?JsonGenerator?jsonGenerator,?SerializerProvider?serializerProvider)?throws?IOException?{????????????????SimpleDateFormat?formatter?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?formattedDate?=?formatter.format(date);????????????????jsonGenerator.writeString(formattedDate);????????????}????????});????????javaTimeModule.addDeserializer(Date.class,?new?JsonDeserializer<>()?{????????????@Override????????????public?Date?deserialize(JsonParser?jsonParser,?DeserializationContext?deserializationContext)?throws?IOException,?JsonProcessingException?{????????????????SimpleDateFormat?format?=?new?SimpleDateFormat(DEFAULT_DATE_TIME_FORMAT);????????????????String?date?=?jsonParser.getText();????????????????try?{????????????????????return?format.parse(date);????????????????}?catch?(ParseException?e)?{????????????????????throw?new?RuntimeException(e);????????????????}????????????}????????});????????objectMapper.registerModule(javaTimeModule);????????return?objectMapper;????}}擴(kuò)充源碼：深入研究SpringMVC數(shù)據(jù)綁定過程接下來進(jìn)入debug模式，看看mvc是如何將我們r(jià)equest中的參數(shù)綁定到我們controller層方法入?yún)⒌?；寫一個(gè)簡單controller，打個(gè)斷點(diǎn)看看方法調(diào)用棧：????@GetMapping("/getDate")????public?LocalDateTime?getDate(@RequestParam?LocalDate?date,?????????????????????????????????@RequestParam?LocalDateTime?dateTime,?????????????????????????????????@RequestParam?Date?originalDate)?{????????System.out.println(date);????????System.out.println(dateTime);????????System.out.println(originalDate);????????return?LocalDateTime.now();????}調(diào)用接口以后，我們看下方法調(diào)用棧中一些關(guān)鍵方法：//進(jìn)入DispatcherServletdoService:942,?DispatcherServlet//處理請求doDispatch:1038,?DispatcherServlet//生成調(diào)用鏈（前處理、實(shí)際調(diào)用方法、后處理）handle:87,?AbstractHandlerMethodAdapter//反射獲取到實(shí)際調(diào)用方法，準(zhǔn)備開始調(diào)用invokeHandlerMethod:895,?RequestMappingHandlerAdapterinvokeAndHandle:102,?ServletInvocableHandlerMethod//這里是關(guān)鍵，參數(shù)從這里開始獲取到invokeForRequest:142,?InvocableHandlerMethoddoInvoke:215,?InvocableHandlerMethod//這個(gè)是Java?reflect調(diào)用，因此一定是在這之前獲取到的參數(shù)invoke:566,?Method根據(jù)上述分析，""" linktype="text" imgurl="" imgdata="null" data-itemshowtype="0" tab="innerlink" data-linktype="2" wah-hotarea="click" hasload="1" style="margin: 0px; padding: 0px; outline: 0px; color: rgb(58, 58, 58); text-decoration: none; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); cursor: pointer; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important;">根據(jù)上述分析，發(fā)現(xiàn)invokeForRequest:142, InvocableHandlerMethod這里的代碼是用來拿到實(shí)際參數(shù)的：

????@Nullable
????public?Object?invokeForRequest(NativeWebRequest?request,?@Nullable?ModelAndViewContainer?mavContainer,
????????????Object...?providedArgs)?throws?Exception?{
????????//這個(gè)方法是獲取參數(shù)的，在這里下個(gè)斷
????????Object[]?args?=?getMethodArgumentValues(request,?mavContainer,?providedArgs);
????????if?(logger.isTraceEnabled())?{
????????????logger.trace("Arguments:?"?+?Arrays.toString(args));
????????}
????????//這里開始調(diào)用方法
????????return?doInvoke(args);
????}

進(jìn)入這個(gè)方法看看是什么操作：

protected?Object[]?getMethodArgumentValues(NativeWebRequest?request,?@Nullable?ModelAndViewContainer?mavContainer,?Object...?providedArgs)?throws?Exception?{
????//獲取方法參數(shù)數(shù)組，包含了入?yún)⑿畔?，比如類型、泛型等?br style="margin: 0px;padding: 0px;outline: 0px;max-width: 100%;box-sizing: border-box !important;overflow-wrap: break-word !important;">????MethodParameter[]?parameters?=?getMethodParameters();
????//這個(gè)用來存放一會從request?parameter轉(zhuǎn)換的參數(shù)
????Object[]?args?=?new?Object[parameters.length];
????for?(int?i?=?0;?i???????MethodParameter?parameter?=?parameters[i];
??????parameter.initParameterNameDiscovery(this.parameterNameDiscoverer);
??????//這里看起來沒啥卵用（providedArgs為空）
??????args[i]?=?resolveProvidedArgument(parameter,?providedArgs);
??????//這里開始獲取到方法實(shí)際調(diào)用的參數(shù)，步進(jìn)
??????if?(this.argumentResolvers.supportsParameter(parameter))?{
????????//從名字就看出來：參數(shù)解析器解析參數(shù)
????????args[i]?=?this.argumentResolvers.resolveArgument(parameter,?mavContainer,?request,?this.dataBinderFactory);
????????continue;
??????}
????}
????return?args;
}

進(jìn)入resolveArgument看看：

public?Object?resolveArgument(MethodParameter?parameter,?@Nullable?ModelAndViewContainer?mavContainer,
??????????????????????????????NativeWebRequest?webRequest,?@Nullable?WebDataBinderFactory?binderFactory)?throws?Exception?{
??//根據(jù)方法入?yún)?，獲取對應(yīng)的解析器
??HandlerMethodArgumentResolver?resolver?=?getArgumentResolver(parameter);
??//開始解析參數(shù)（把請求中的parameter轉(zhuǎn)為方法的入?yún)ⅲ?br style="margin: 0px;padding: 0px;outline: 0px;max-width: 100%;box-sizing: border-box !important;overflow-wrap: break-word !important;">??return?resolver.resolveArgument(parameter,?mavContainer,?webRequest,?binderFactory);
}

這里根據(jù)參數(shù)獲取相應(yīng)的參數(shù)解析器，看看內(nèi)部如何獲取的：

//遍歷，調(diào)用supportParameter方法，跟進(jìn)看看
for?(HandlerMethodArgumentResolver?methodArgumentResolver?:?this.argumentResolvers)?{
??if?(methodArgumentResolver.supportsParameter(parameter))?{
????result?=?methodArgumentResolver;
????this.argumentResolverCache.put(parameter,?result);
????break;
??}
}

這里，遍歷參數(shù)解析器，查找有沒有適合的解析器！那么，有哪些參數(shù)解析器呢(我測試的時(shí)候有26個(gè))？？？我列出幾個(gè)重要的看看，是不是很眼熟?。?！

{RequestParamMethodArgumentResolver@7686}
{PathVariableMethodArgumentResolver@8359}
{RequestResponseBodyMethodProcessor@8366}
{RequestPartMethodArgumentResolver@8367}

我們進(jìn)入最常用的一個(gè)解析器看看他的supportsParameter方法，發(fā)現(xiàn)就是通過參數(shù)注解來獲取相應(yīng)的解析器的。

????public?boolean?supportsParameter(MethodParameter?parameter)?{
????????//如果參數(shù)擁有注解@RequestParam，則走這個(gè)分支（知道為什么上文要對RequestParam和Json兩種數(shù)據(jù)區(qū)別對待了把）
????????if?(parameter.hasParameterAnnotation(RequestParam.class))?{
????????????//這個(gè)似乎是對Optional類型的參數(shù)進(jìn)行處理的
????????????if?(Map.class.isAssignableFrom(parameter.nestedIfOptional().getNestedParameterType()))?{
????????????????RequestParam?requestParam?=?parameter.getParameterAnnotation(RequestParam.class);
????????????????return?(requestParam?!=?null?&&?StringUtils.hasText(requestParam.name()));
????????????}
????????????else?{
????????????????return?true;
????????????}
????????}
????????//......
????}

也就是說，對于@RequestParam和@RequestBody以及@PathVariable注解的參數(shù)，SpringMVC會使用不同的參數(shù)解析器進(jìn)行數(shù)據(jù)綁定！?那么，這三種解析器分別使用什么Converter解析參數(shù)呢？我們分別進(jìn)入三種解析器看一看：?首先看下RequestParamMethodArgumentResolver發(fā)現(xiàn)內(nèi)部使用WebDataBinder進(jìn)行數(shù)據(jù)綁定，底層使用的是ConversionService （也就是我們的Converter注入的地方）

WebDataBinder?binder?=?binderFactory.createBinder(webRequest,?null,?namedValueInfo.name);
//通過DataBinder進(jìn)行數(shù)據(jù)綁定的
arg?=?binder.convertIfNecessary(arg,?parameter.getParameterType(),?parameter);

//跟進(jìn)convertIfNecessary()
public??T?convertIfNecessary(@Nullable?Object?value,?@Nullable?Class?requiredType,
????????????????????????????????@Nullable?MethodParameter?methodParam)?throws?TypeMismatchException?{

??return?getTypeConverter().convertIfNecessary(value,?requiredType,?methodParam);
}

//繼續(xù)跟進(jìn)，看到了把
ConversionService?conversionService?=?this.propertyEditorRegistry.getConversionService();
if?(editor?==?null?&&?conversionService?!=?null?&&?newValue?!=?null?&&?typeDescriptor?!=?null)?{
??TypeDescriptor?sourceTypeDesc?=?TypeDescriptor.forObject(newValue);
??if?(conversionService.canConvert(sourceTypeDesc,?typeDescriptor))?{
????try?{
??????return?(T)?conversionService.convert(newValue,?sourceTypeDesc,?typeDescriptor);
????}
????catch?(ConversionFailedException?ex)?{
??????//?fallback?to?default?conversion?logic?below
??????conversionAttemptEx?=?ex;
????}
??}
}

然后看下RequestResponseBodyMethodProcessor發(fā)現(xiàn)使用的轉(zhuǎn)換器是HttpMessageConverter類型的：

//resolveArgument方法內(nèi)部調(diào)用下面進(jìn)行參數(shù)解析
Object?arg?=?readWithMessageConverters(webRequest,?parameter,?parameter.getNestedGenericParameterType());

//step?into?readWithMessageConverters()，我們看到這里的Converter是HttpMessageConverter
for?(HttpMessageConverter?converter?:?this.messageConverters)?{
??Class>?converterType?=?(Class>)?converter.getClass();
??GenericHttpMessageConverter?genericConverter?=
????(converter?instanceof?GenericHttpMessageConverter???(GenericHttpMessageConverter)?converter?:?null);
??if?(genericConverter?!=?null???genericConverter.canRead(targetType,?contextClass,?contentType)?:
??????(targetClass?!=?null?&&?converter.canRead(targetClass,?contentType)))?{
????if?(message.hasBody())?{
??????HttpInputMessage?msgToUse?=
????????getAdvice().beforeBodyRead(message,?parameter,?targetType,?converterType);
??????body?=?(genericConverter?!=?null???genericConverter.read(targetType,?contextClass,?msgToUse)?:
??????????????((HttpMessageConverter)?converter).read(targetClass,?msgToUse));
??????body?=?getAdvice().afterBodyRead(body,?msgToUse,?parameter,?targetType,?converterType);
????}
????else?{
??????body?=?getAdvice().handleEmptyBody(null,?message,?parameter,?targetType,?converterType);
????}
????break;
??}
}

最后看下PathVariableMethodArgumentResolver發(fā)現(xiàn) 和RequestParam走的執(zhí)行路徑一致（二者都是繼承自AbstractNamedValueMethodArgumentResolver解析器），因此代碼就不貼了。

總結(jié)

如果要轉(zhuǎn)換request傳來的參數(shù)到我們指定的類型，根據(jù)入?yún)⒆⒔庖M(jìn)行區(qū)分：

• 如果是RequestBody，那么通過配置ObjectMapper（這個(gè)玩意兒會注入到Jackson的HttpMessagConverter里面，即MappingJackson2HttpMessageConverter中）來實(shí)現(xiàn)Json格式數(shù)據(jù)的序列化和反序列化；
• 如果是RequestParam或者PathVariable類型的參數(shù)，通過配置Converter實(shí)現(xiàn)參數(shù)轉(zhuǎn)換（這些Converter會注入到ConversionService中）。
  
  

END

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