This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Framework 6.1.14!

Type Conversion

By default, formatters for various number and date types are installed, along with support for customization via @NumberFormat, @DurationFormat and @DateTimeFormat on fields.

To register custom formatters and converters, use the following:

  • Java

  • Kotlin

  • Xml

@Configuration
public class WebConfiguration implements WebMvcConfigurer {

	@Override
	public void addFormatters(FormatterRegistry registry) {
		// ...
	}
}
@Configuration
class WebConfiguration : WebMvcConfigurer {

	override fun addFormatters(registry: FormatterRegistry) {
		// ...
	}
}
<mvc:annotation-driven conversion-service="conversionService"/>

<bean id="conversionService"
	  class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
	<property name="converters">
		<set>
			<bean class="org.example.MyConverter"/>
		</set>
	</property>
	<property name="formatters">
		<set>
			<bean class="org.example.MyFormatter"/>
			<bean class="org.example.MyAnnotationFormatterFactory"/>
		</set>
	</property>
	<property name="formatterRegistrars">
		<set>
			<bean class="org.example.MyFormatterRegistrar"/>
		</set>
	</property>
</bean>

By default Spring MVC considers the request Locale when parsing and formatting date values. This works for forms where dates are represented as Strings with "input" form fields. For "date" and "time" form fields, however, browsers use a fixed format defined in the HTML spec. For such cases date and time formatting can be customized as follows:

  • Java

  • Kotlin

@Configuration
public class DateTimeWebConfiguration implements WebMvcConfigurer {

	@Override
	public void addFormatters(FormatterRegistry registry) {
		DateTimeFormatterRegistrar registrar = new DateTimeFormatterRegistrar();
		registrar.setUseIsoFormat(true);
		registrar.registerFormatters(registry);
	}
}
@Configuration
class DateTimeWebConfiguration : WebMvcConfigurer {

	override fun addFormatters(registry: FormatterRegistry) {
		DateTimeFormatterRegistrar().apply {
			setUseIsoFormat(true)
			registerFormatters(registry)
		}
	}
}
See the FormatterRegistrar SPI and the FormattingConversionServiceFactoryBean for more information on when to use FormatterRegistrar implementations.