localdatetime格式化,springboot全局日期格式化
目录
【1】格式化后台传给前端的日期跳羚对日期/日期时间配置第一种方式:配置本地日期时间序列器第二种方式:@JsonFormat【2】前台传线格式日期给后台 配置全局的日期转换器localDateTimeConvert配置日期格式化器【3】转换是什么时候添加到转换服务中的?跳趾启动的时候运行奔跑方法 尝试获取ConversionService获取应用转换服务应用转换服务。配置defaultconversionservice。adddefaultconvertersaddDefaultFormatters添加格式化器 addApplicationFormatters(注册表) addApplicationConverters(注册表)
【1】格式化后台传给前端的日期
首先第一点需要知道的是跳羚默认依赖的数据框架是杰克逊.
当使用@ResponseBody注解返回数据格式数据时就是该框架在起作用。
SpringBoot对Date/DateTime配置
如果字段属性是日期而非本地日期时间时,通常我们会在应用程序.属性里面配置如下:
春天。MVC。日期格式=yyyy-MM-DD hh :MM : ssstring。杰克逊。日期格式=yyyy-MM-DD hh :MM 3360 ssstring。杰克逊。时区=GMT 8春季。杰克逊。序列化。将日期作为时间戳写入=假如下图所示春天。杰克逊开头的配置会被杰克逊财产类获取进行使用。
当返回数据格式的时候,杰克逊就会根据配置文件中日期格式化的配置对结果进行处理。
但是如果字段属性为LocalDateTime呢?这种配置就失去了作用。
第一种方式:配置localDateTimeSerializer
这时候建议配置如下:
/** *由江gc于2020/7/1创作. Configurationpublic类LocalDateTimeSerializerConfig { @ Value($ { spring。杰克逊。日期格式: yyyy-MM-DD hh :MM : ss } )私有字符串模式;//本地日期时间序列化器@ Bean public LocalDateTimeSerializer LocalDateTimeSerializer(){ return new LocalDateTimeSerializer(datetime formatter。的模式(pattern));} //本地日期时间反序列化器@ Bean public localdatetimedeserizer localdatetimedeserizer(){ return new localdatetimedeserizer(datetime formatter。的模式(pattern));} @ Bean public Jackson 2 objectmapperbuildercustomizer Jackson 2 objectmapperbuildercustomizer(){//return new Jackson 2 objectmapperbuildercustomizer(){//@ Override//public void customize(Jackson 2 objectmapperbuilder jacksonObjectMapperBuilder){ jacksonObjectMapperBuilder。featurestodisable(序列化功能.FAIL _ ON _ EMPTY _ BEANS);//
jacksonObjectMapperBuilder.serializerByType(LocalDateTime.class, localDateTimeSerializer());// jacksonObjectMapperBuilder.deserializerByType(LocalDateTime.class,localDateTimeDeserializer());// }// }; //这种方式同上 return builder -> { builder.serializerByType(LocalDateTime.class, localDateTimeSerializer()); builder.deserializerByType(LocalDateTime.class,localDateTimeDeserializer()); builder.simpleDateFormat(pattern); }; }}
第二种方式:@JsonFormat
这种配置方式自然是全局的,如果想针对某个字段特殊处理,可以在类字段上面添加注解@JsonFormat:
@JsonFormat( pattern = "yyyy-MM-dd HH:mm:ss",timezone="GMT+8") private Date createdDate; @JsonFormat( pattern = "yyyy-MM-dd HH:mm:ss") private LocalDateTime createdTime;
【2】前台传String格式日期给后台
如下所示,前台传参2020-08-30 11:11:11,后台使用LocalDateTime 接收。
通常会报错类似如下:
nested exception is org.springframework.core.convert.ConversionFailedException:
Failed to convert from type [java.lang.String] to type [java.time.LocalDateTime ]
很显然是在参数绑定的时候没有找到合适的转换器把String转换为对应的格式。
① 配置全局的日期转换器localDateTimeConvert
@Beanpublic Converter<String, LocalDateTime> localDateTimeConvert() { return new Converter<String, LocalDateTime>() { @Override public LocalDateTime convert(String source) { DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"); LocalDateTime dateTime = null; try { //2020-01-01 00:00:00 switch (source.length()){ case 10: logger.debug("传过来的是日期格式:{}",source); source=source+" 00:00:00"; break; case 13: logger.debug("传过来的是日期 小时格式:{}",source); source=source+":00:00"; break; case 16: logger.debug("传过来的是日期 小时:分钟格式:{}",source); source=source+":00"; break; } dateTime = LocalDateTime.parse(source, df); } catch (Exception e) { logger.error(e.getMessage(),e); } return dateTime; } };}
实现原理简要描述
在进行参数绑定的时候,会使用WebDataBinder对象。而创建WebDataBinder对象时,会遍历DefaultDataBinderFactory.initializer,使用其WebBindingInitializer initializer对WebDataBinder对象进行初始化。
初始化方法具体可见ConfigurableWebBindingInitializer.initBinder(WebDataBinder binder),源码如下:
public void initBinder(WebDataBinder binder) { binder.setAutoGrowNestedPaths(this.autoGrowNestedPaths); if (this.directFieldAccess) { binder.initDirectFieldAccess(); } //设置messageCodesResolver if (this.messageCodesResolver != null) { binder.setMessageCodesResolver(this.messageCodesResolver); } //设置bindingErrorProcessor if (this.bindingErrorProcessor != null) { binder.setBindingErrorProcessor(this.bindingErrorProcessor); } //设置validator if (this.validator != null && binder.getTarget() != null && this.validator.supports(binder.getTarget().getClass())) { binder.setValidator(this.validator); } //设置conversionService if (this.conversionService != null) { binder.setConversionService(this.conversionService); } if (this.propertyEditorRegistrars != null) { PropertyEditorRegistrar[] var2 = this.propertyEditorRegistrars; int var3 = var2.length; for(int var4 = 0; var4 < var3; ++var4) { PropertyEditorRegistrar propertyEditorRegistrar = var2[var4]; propertyEditorRegistrar.registerCustomEditors(binder); } } }
而conversionService中包含了许多的convert-类型格式化器。在WebDataBinder进行参数绑定的时候就会使用不同的格式化器即不同的convert进行参数类型转换。
关于参数绑定的过程,有兴趣的可以跟踪DataBinder.doBind方法,在这个过程中会对前台传输的值进行类型转换为目标参数需要的类型。自定义的localDateTimeConvert也是在这里被用到的。
如下所示前台传String格式给后台参数endDate,参数类型为java.time.LocalDateTime。
找到我们自定义的converter
调用convert进行类型转换:
可以看到转换后的结果为:
② 配置日期格式化器
/** * yyyy-MM-dd HH:mm:ss String-localDateTime * @return */ @Bean public Formatter<LocalDateTime> localDateTimeFormatter() { return new Formatter<LocalDateTime>() { @Override public LocalDateTime parse(String text, Locale locale) throws ParseException { return LocalDateTime.parse(text, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")); } @Override public String print(LocalDateTime localDateTime, Locale locale) { DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"); return formatter.format(localDateTime); } }; }
自定义的格式化器会在SpringBoot启动时自动化配置过程中被加入,具体可以参考如下代码。
WebMvcAutoConfiguration.mvcConversionService:
@Bean@Overridepublic FormattingConversionService mvcConversionService() {WebConversionService conversionService = new WebConversionService(this.mvcProperties.getDateFormat());addFormatters(conversionService);return conversionService;}
【3】convert是什么时候添加到ConversionService中的?
① SpringBoot启动的时候运行run方法
其会走到SpringApplication.configureEnvironment方法处:
protected void configureEnvironment(ConfigurableEnvironment environment, String[] args) { if (this.addConversionService) { //从这里跟踪 ConversionService conversionService = ApplicationConversionService.getSharedInstance(); environment.setConversionService((ConfigurableConversionService)conversionService); } this.configurePropertySources(environment, args); this.configureProfiles(environment, args); }
② 尝试获取ConversionService
ApplicationConversionService.getSharedInstance如下所示,这里可以看到其使用了设计模式中的懒汉式之双重校验锁来获取单例。
public static ConversionService getSharedInstance() { ApplicationConversionService sharedInstance = sharedInstance; if (sharedInstance == null) { Class var1 = ApplicationConversionService.class; synchronized(ApplicationConversionService.class) { sharedInstance = sharedInstance; if (sharedInstance == null) { sharedInstance = new ApplicationConversionService(); sharedInstance = sharedInstance; } } } return sharedInstance; }
③ 获取ApplicationConversionService
继续对象创建过程会发现其走到了configure处:
public ApplicationConversionService(StringValueResolver embeddedValueResolver) { if (embeddedValueResolver != null) { this.setEmbeddedValueResolver(embeddedValueResolver); }//我们从这里继续跟进 configure(this); }
这里我们顺带看一下ApplicationConversionService的类继承示意图(其不只是可以作为ConversionService还可以作为ConverterRegistry与FormatterRegistry):
④ ApplicationConversionService.configure
创建ApplicationConversionService时会对其进行配置,这里很重要。其会注入默认的Converter和Formatter:
public static void configure(FormatterRegistry registry) { DefaultConversionService.addDefaultConverters(registry); DefaultFormattingConversionService.addDefaultFormatters(registry); addApplicationFormatters(registry); addApplicationConverters(registry); }
⑤ DefaultConversionService.addDefaultConverters
该方法执行完,会添加52个类型转换器:
public static void addDefaultConverters(ConverterRegistry converterRegistry) {addScalarConverters(converterRegistry);addCollectionConverters(converterRegistry);converterRegistry.addConverter(new ByteBufferConverter((ConversionService) converterRegistry));converterRegistry.addConverter(new StringToTimeZoneConverter());converterRegistry.addConverter(new ZoneIdToTimeZoneConverter());converterRegistry.addConverter(new ZonedDateTimeToCalendarConverter());converterRegistry.addConverter(new ObjectToObjectConverter());converterRegistry.addConverter(new IdToEntityConverter((ConversionService) converterRegistry));converterRegistry.addConverter(new FallbackObjectToStringConverter());converterRegistry.addConverter(new ObjectToOptionalConverter((ConversionService) converterRegistry));}
addScalarConverters(converterRegistry);如下所示:
private static void addScalarConverters(ConverterRegistry converterRegistry) {converterRegistry.addConverterFactory(new NumberToNumberConverterFactory());converterRegistry.addConverterFactory(new StringToNumberConverterFactory());converterRegistry.addConverter(Number.class, String.class, new ObjectToStringConverter());converterRegistry.addConverter(new StringToCharacterConverter());converterRegistry.addConverter(Character.class, String.class, new ObjectToStringConverter());converterRegistry.addConverter(new NumberToCharacterConverter());converterRegistry.addConverterFactory(new CharacterToNumberFactory());converterRegistry.addConverter(new StringToBooleanConverter());converterRegistry.addConverter(Boolean.class, String.class, new ObjectToStringConverter());converterRegistry.addConverterFactory(new StringToEnumConverterFactory());converterRegistry.addConverter(new EnumToStringConverter((ConversionService) converterRegistry));converterRegistry.addConverterFactory(new IntegerToEnumConverterFactory());converterRegistry.addConverter(new EnumToIntegerConverter((ConversionService) converterRegistry));converterRegistry.addConverter(new StringToLocaleConverter());converterRegistry.addConverter(Locale.class, String.class, new ObjectToStringConverter());converterRegistry.addConverter(new StringToCharsetConverter());converterRegistry.addConverter(Charset.class, String.class, new ObjectToStringConverter());converterRegistry.addConverter(new StringToCurrencyConverter());converterRegistry.addConverter(Currency.class, String.class, new ObjectToStringConverter());converterRegistry.addConverter(new StringToPropertiesConverter());converterRegistry.addConverter(new PropertiesToStringConverter());converterRegistry.addConverter(new StringToUUIDConverter());converterRegistry.addConverter(UUID.class, String.class, new ObjectToStringConverter());}
这里会添加23个类型转换器:
添加集合处理的类型转换器(这里会添加17个类型转换器):
public static void addCollectionConverters(ConverterRegistry converterRegistry) {ConversionService conversionService = (ConversionService) converterRegistry;converterRegistry.addConverter(new ArrayToCollectionConverter(conversionService));converterRegistry.addConverter(new CollectionToArrayConverter(conversionService));converterRegistry.addConverter(new ArrayToArrayConverter(conversionService));converterRegistry.addConverter(new CollectionToCollectionConverter(conversionService));converterRegistry.addConverter(new MapToMapConverter(conversionService));converterRegistry.addConverter(new ArrayToStringConverter(conversionService));converterRegistry.addConverter(new StringToArrayConverter(conversionService));converterRegistry.addConverter(new ArrayToObjectConverter(conversionService));converterRegistry.addConverter(new ObjectToArrayConverter(conversionService));converterRegistry.addConverter(new CollectionToStringConverter(conversionService));converterRegistry.addConverter(new StringToCollectionConverter(conversionService));converterRegistry.addConverter(new CollectionToObjectConverter(conversionService));converterRegistry.addConverter(new ObjectToCollectionConverter(conversionService));converterRegistry.addConverter(new StreamConverter(conversionService));}
⑥ addDefaultFormatters添加格式化器
/** * Add formatters appropriate for most environments: including number formatters, * JSR-354 Money & Currency formatters, JSR-310 Date-Time and/or Joda-Time formatters, * depending on the presence of the corresponding API on the classpath. * @param formatterRegistry the service to register default formatters with */public static void addDefaultFormatters(FormatterRegistry formatterRegistry) {// Default handling of number valuesformatterRegistry.addFormatterForFieldAnnotation(new NumberFormatAnnotationFormatterFactory());// Default handling of monetary valuesif (jsr354Present) {formatterRegistry.addFormatter(new CurrencyUnitFormatter());formatterRegistry.addFormatter(new MonetaryAmountFormatter());formatterRegistry.addFormatterForFieldAnnotation(new Jsr354NumberFormatAnnotationFormatterFactory());}// Default handling of date-time values// just handling JSR-310 specific date and time typesnew DateTimeFormatterRegistrar().registerFormatters(formatterRegistry);if (jodaTimePresent) {// handles Joda-specific types as well as Date, Calendar, Longnew JodaTimeFormatterRegistrar().registerFormatters(formatterRegistry);}else {// regular DateFormat-based Date, Calendar, Long convertersnew DateFormatterRegistrar().registerFormatters(formatterRegistry);}}
DateTimeFormatterRegistrar.registerFormatters
@Overridepublic void registerFormatters(FormatterRegistry registry) {DateTimeConverters.registerConverters(registry);DateTimeFormatter df = getFormatter(Type.DATE);DateTimeFormatter tf = getFormatter(Type.TIME);DateTimeFormatter dtf = getFormatter(Type.DATE_TIME);// Efficient ISO_LOCAL_* variants for printing since they are twice as fast...registry.addFormatterForFieldType(LocalDate.class,new TemporalAccessorPrinter(df == DateTimeFormatter.ISO_DATE ? DateTimeFormatter.ISO_LOCAL_DATE : df),new TemporalAccessorParser(LocalDate.class, df));registry.addFormatterForFieldType(LocalTime.class,new TemporalAccessorPrinter(tf == DateTimeFormatter.ISO_TIME ? DateTimeFormatter.ISO_LOCAL_TIME : tf),new TemporalAccessorParser(LocalTime.class, tf));registry.addFormatterForFieldType(LocalDateTime.class,new TemporalAccessorPrinter(dtf == DateTimeFormatter.ISO_DATE_TIME ? DateTimeFormatter.ISO_LOCAL_DATE_TIME : dtf),new TemporalAccessorParser(LocalDateTime.class, dtf));registry.addFormatterForFieldType(ZonedDateTime.class,new TemporalAccessorPrinter(dtf),new TemporalAccessorParser(ZonedDateTime.class, dtf));registry.addFormatterForFieldType(OffsetDateTime.class,new TemporalAccessorPrinter(dtf),new TemporalAccessorParser(OffsetDateTime.class, dtf));registry.addFormatterForFieldType(OffsetTime.class,new TemporalAccessorPrinter(tf),new TemporalAccessorParser(OffsetTime.class, tf));registry.addFormatterForFieldType(Instant.class, new InstantFormatter());registry.addFormatterForFieldType(Period.class, new PeriodFormatter());registry.addFormatterForFieldType(Duration.class, new DurationFormatter());registry.addFormatterForFieldType(Year.class, new YearFormatter());registry.addFormatterForFieldType(Month.class, new MonthFormatter());registry.addFormatterForFieldType(YearMonth.class, new YearMonthFormatter());registry.addFormatterForFieldType(MonthDay.class, new MonthDayFormatter());registry.addFormatterForFieldAnnotation(new Jsr310DateTimeFormatAnnotationFormatterFactory());}
DateTimeConverters.registerConverters
public static void registerConverters(ConverterRegistry registry) {DateFormatterRegistrar.addDateConverters(registry);registry.addConverter(new LocalDateTimeToLocalDateConverter());registry.addConverter(new LocalDateTimeToLocalTimeConverter());registry.addConverter(new ZonedDateTimeToLocalDateConverter());registry.addConverter(new ZonedDateTimeToLocalTimeConverter());registry.addConverter(new ZonedDateTimeToLocalDateTimeConverter());registry.addConverter(new ZonedDateTimeToOffsetDateTimeConverter());registry.addConverter(new ZonedDateTimeToInstantConverter());registry.addConverter(new OffsetDateTimeToLocalDateConverter());registry.addConverter(new OffsetDateTimeToLocalTimeConverter());registry.addConverter(new OffsetDateTimeToLocalDateTimeConverter());registry.addConverter(new OffsetDateTimeToZonedDateTimeConverter());registry.addConverter(new OffsetDateTimeToInstantConverter());registry.addConverter(new CalendarToZonedDateTimeConverter());registry.addConverter(new CalendarToOffsetDateTimeConverter());registry.addConverter(new CalendarToLocalDateConverter());registry.addConverter(new CalendarToLocalTimeConverter());registry.addConverter(new CalendarToLocalDateTimeConverter());registry.addConverter(new CalendarToInstantConverter());registry.addConverter(new LongToInstantConverter());registry.addConverter(new InstantToLongConverter());}
DateFormatterRegistrar.addDateConverters
public static void addDateConverters(ConverterRegistry converterRegistry) {converterRegistry.addConverter(new DateToLongConverter());converterRegistry.addConverter(new DateToCalendarConverter());converterRegistry.addConverter(new CalendarToDateConverter());converterRegistry.addConverter(new CalendarToLongConverter());converterRegistry.addConverter(new LongToDateConverter());converterRegistry.addConverter(new LongToCalendarConverter());}
⑦ addApplicationFormatters(registry)
添加全局格式化器:
public static void addApplicationFormatters(FormatterRegistry registry) { registry.addFormatter(new CharArrayFormatter()); registry.addFormatter(new InetAddressFormatter()); registry.addFormatter(new IsoOffsetFormatter()); }
⑧ addApplicationConverters(registry)
添加全局类型转换器:
public static void addApplicationConverters(ConverterRegistry registry) { addDelimitedStringConverters(registry); registry.addConverter(new StringToDurationConverter()); registry.addConverter(new DurationToStringConverter()); registry.addConverter(new NumberToDurationConverter()); registry.addConverter(new DurationToNumberConverter()); registry.addConverter(new StringToDataSizeConverter()); registry.addConverter(new NumberToDataSizeConverter()); registry.addConverter(new StringToFileConverter()); registry.addConverterFactory(new LenientStringToEnumConverterFactory()); registry.addConverterFactory(new LenientBooleanToEnumConverterFactory()); } public static void addDelimitedStringConverters(ConverterRegistry registry) { ConversionService service = (ConversionService)registry; registry.addConverter(new ArrayToDelimitedStringConverter(service)); registry.addConverter(new CollectionToDelimitedStringConverter(service)); registry.addConverter(new DelimitedStringToArrayConverter(service)); registry.addConverter(new DelimitedStringToCollectionConverter(service)); }
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