Spring - Built-in converter List

Spring comes with predefined converters.

The built-in converters are not public, so we cannot find them in API docs. To know what types can be converted by default please use your IDE to view hierarchy of Converter interface.

Following code list all converters defined in Spring core:

package com.logicbig.example;

import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider;
import org.springframework.core.convert.converter.Converter;
import org.springframework.core.type.filter.AssignableTypeFilter;
import java.util.Set;

public class SpringBuiltInConvertersFinder {
  public static void main(String[] args) {
      ClassPathScanningCandidateComponentProvider provider =
              new ClassPathScanningCandidateComponentProvider(false);
      provider.addIncludeFilter(new AssignableTypeFilter(Converter.class));
      Set<BeanDefinition> components = provider.findCandidateComponents("org/springframework");
      components.stream()
                .map(BeanDefinition::getBeanClassName)
                .forEach(System.out::println);
  }
}

Output

org.springframework.format.datetime.DateFormatterRegistrar$DateToCalendarConverter
org.springframework.format.datetime.DateFormatterRegistrar$CalendarToLongConverter
org.springframework.format.datetime.joda.JodaTimeConverters$DateTimeToCalendarConverter
org.springframework.format.datetime.joda.JodaTimeConverters$DateTimeToDateConverter
org.springframework.format.datetime.joda.JodaTimeConverters$LongToReadableInstantConverter
org.springframework.format.datetime.joda.JodaTimeConverters$CalendarToReadableInstantConverter
org.springframework.format.datetime.joda.JodaTimeConverters$DateTimeToMutableDateTimeConverter
org.springframework.format.datetime.joda.JodaTimeConverters$DateTimeToLocalDateTimeConverter
org.springframework.format.datetime.joda.JodaTimeConverters$LocalDateTimeToLocalTimeConverter
org.springframework.format.datetime.joda.JodaTimeConverters$DateToReadableInstantConverter
org.springframework.format.datetime.joda.JodaTimeConverters$DateTimeToInstantConverter
org.springframework.format.datetime.joda.JodaTimeConverters$DateTimeToDateMidnightConverter
org.springframework.format.datetime.joda.JodaTimeConverters$DateTimeToLocalDateConverter
org.springframework.format.datetime.joda.JodaTimeConverters$DateTimeToLongConverter
org.springframework.format.datetime.joda.JodaTimeConverters$DateTimeToLocalTimeConverter
org.springframework.format.datetime.joda.JodaTimeConverters$LocalDateTimeToLocalDateConverter
org.springframework.format.datetime.standard.DateTimeConverters$InstantToLongConverter
org.springframework.format.datetime.standard.DateTimeConverters$OffsetDateTimeToLocalTimeConverter
org.springframework.format.datetime.standard.DateTimeConverters$ZonedDateTimeToOffsetDateTimeConverter
org.springframework.format.datetime.standard.DateTimeConverters$CalendarToOffsetDateTimeConverter
org.springframework.format.datetime.standard.DateTimeConverters$ZonedDateTimeToLocalDateTimeConverter
org.springframework.format.datetime.standard.DateTimeConverters$CalendarToZonedDateTimeConverter
org.springframework.format.datetime.standard.DateTimeConverters$OffsetDateTimeToZonedDateTimeConverter
org.springframework.format.datetime.standard.DateTimeConverters$ZonedDateTimeToLocalDateConverter
org.springframework.format.datetime.standard.DateTimeConverters$LocalDateTimeToLocalTimeConverter
org.springframework.format.datetime.standard.DateTimeConverters$OffsetDateTimeToInstantConverter
org.springframework.format.datetime.standard.DateTimeConverters$OffsetDateTimeToLocalDateConverter
org.springframework.format.datetime.standard.DateTimeConverters$LocalDateTimeToLocalDateConverter
org.springframework.format.datetime.standard.DateTimeConverters$CalendarToLocalDateTimeConverter
org.springframework.format.datetime.standard.DateTimeConverters$ZonedDateTimeToInstantConverter
org.springframework.format.datetime.standard.DateTimeConverters$CalendarToInstantConverter
org.springframework.format.datetime.standard.DateTimeConverters$OffsetDateTimeToLocalDateTimeConverter
org.springframework.format.datetime.standard.DateTimeConverters$CalendarToLocalTimeConverter
org.springframework.format.datetime.standard.DateTimeConverters$ZonedDateTimeToLocalTimeConverter
org.springframework.format.datetime.standard.DateTimeConverters$CalendarToLocalDateConverter
org.springframework.format.datetime.standard.DateTimeConverters$LongToInstantConverter
org.springframework.format.datetime.DateFormatterRegistrar$CalendarToDateConverter
org.springframework.format.datetime.DateFormatterRegistrar$DateToLongConverter
org.springframework.format.datetime.DateFormatterRegistrar$LongToDateConverter
org.springframework.format.datetime.DateFormatterRegistrar$LongToCalendarConverter
org.springframework.core.convert.support.PropertiesToStringConverter
org.springframework.core.convert.support.StringToUUIDConverter
org.springframework.core.convert.support.StringToNumberConverterFactory$StringToNumber
org.springframework.core.convert.support.ZoneIdToTimeZoneConverter
org.springframework.core.convert.support.NumberToNumberConverterFactory$NumberToNumber
org.springframework.core.convert.support.StringToBooleanConverter
org.springframework.core.convert.support.StringToCharacterConverter
org.springframework.core.convert.support.ObjectToStringConverter
org.springframework.core.convert.support.EnumToStringConverter
org.springframework.core.convert.support.StringToCharsetConverter
org.springframework.core.convert.support.EnumToIntegerConverter
org.springframework.core.convert.support.StringToCurrencyConverter
org.springframework.core.convert.support.NumberToCharacterConverter
org.springframework.core.convert.support.ZonedDateTimeToCalendarConverter
org.springframework.core.convert.support.StringToLocaleConverter
org.springframework.core.convert.support.CharacterToNumberFactory$CharacterToNumber
org.springframework.core.convert.support.StringToPropertiesConverter
org.springframework.core.convert.support.StringToTimeZoneConverter
org.springframework.core.convert.converter.ConvertingComparator$ConversionServiceConverter
org.springframework.core.serializer.support.SerializingConverter
org.springframework.core.serializer.support.DeserializingConverter

Converters registered with DefaultConversionService

DefaultConversionService doesn't provide some public methods to see what Converters are registered by default, but we can use reflection to find that out:

package com.logicbig.example;

import org.springframework.core.convert.support.DefaultConversionService;
import org.springframework.core.convert.support.GenericConversionService;
import java.lang.reflect.Field;

public class ConvertersRegisteredFinder {

  public static void main(String[] args) throws Exception {
      DefaultConversionService service = new DefaultConversionService();
      Field converters = GenericConversionService.class.getDeclaredField("converters");
      converters.setAccessible(true);
      Object o = converters.get(service);
      System.out.println(o.toString().replaceAll("@.+\n", "\n"));
  }
}

Output

ConversionService converters =
	java.lang.Boolean -> java.lang.String : org.springframework.core.convert.support.ObjectToStringConverter
	java.lang.Character -> java.lang.Number : org.springframework.core.convert.support.CharacterToNumberFactory
	java.lang.Character -> java.lang.String : org.springframework.core.convert.support.ObjectToStringConverter
	java.lang.Enum -> java.lang.Integer : org.springframework.core.convert.support.EnumToIntegerConverter
	java.lang.Enum -> java.lang.String : org.springframework.core.convert.support.EnumToStringConverter
	java.lang.Integer -> java.lang.Enum : org.springframework.core.convert.support.IntegerToEnumConverterFactory
	java.lang.Number -> java.lang.Character : org.springframework.core.convert.support.NumberToCharacterConverter
	java.lang.Number -> java.lang.Number : org.springframework.core.convert.support.NumberToNumberConverterFactory
	java.lang.Number -> java.lang.String : org.springframework.core.convert.support.ObjectToStringConverter
	java.lang.String -> java.lang.Boolean : org.springframework.core.convert.support.StringToBooleanConverter
	java.lang.String -> java.lang.Character : org.springframework.core.convert.support.StringToCharacterConverter
	java.lang.String -> java.lang.Enum : org.springframework.core.convert.support.StringToEnumConverterFactory
	java.lang.String -> java.lang.Number : org.springframework.core.convert.support.StringToNumberConverterFactory
	java.lang.String -> java.nio.charset.Charset : org.springframework.core.convert.support.StringToCharsetConverter
	java.lang.String -> java.util.Currency : org.springframework.core.convert.support.StringToCurrencyConverter
	java.lang.String -> java.util.Locale : org.springframework.core.convert.support.StringToLocaleConverter
	java.lang.String -> java.util.Properties : org.springframework.core.convert.support.StringToPropertiesConverter
	java.lang.String -> java.util.TimeZone : org.springframework.core.convert.support.StringToTimeZoneConverter
	java.lang.String -> java.util.UUID : org.springframework.core.convert.support.StringToUUIDConverter
	java.nio.charset.Charset -> java.lang.String : org.springframework.core.convert.support.ObjectToStringConverter
	java.time.ZoneId -> java.util.TimeZone : org.springframework.core.convert.support.ZoneIdToTimeZoneConverter
	java.time.ZonedDateTime -> java.util.Calendar : org.springframework.core.convert.support.ZonedDateTimeToCalendarConverter
	java.util.Currency -> java.lang.String : org.springframework.core.convert.support.ObjectToStringConverter
	java.util.Locale -> java.lang.String : org.springframework.core.convert.support.ObjectToStringConverter
	java.util.Properties -> java.lang.String : org.springframework.core.convert.support.PropertiesToStringConverter
	java.util.UUID -> java.lang.String : org.springframework.core.convert.support.ObjectToStringConverter
	org.springframework.core.convert.support.ArrayToArrayConverter
	org.springframework.core.convert.support.ArrayToCollectionConverter
	org.springframework.core.convert.support.ArrayToObjectConverter
	org.springframework.core.convert.support.ArrayToStringConverter
	org.springframework.core.convert.support.ByteBufferConverter
	org.springframework.core.convert.support.ByteBufferConverter
	org.springframework.core.convert.support.ByteBufferConverter
	org.springframework.core.convert.support.ByteBufferConverter
	org.springframework.core.convert.support.CollectionToArrayConverter
	org.springframework.core.convert.support.CollectionToCollectionConverter
	org.springframework.core.convert.support.CollectionToObjectConverter
	org.springframework.core.convert.support.CollectionToStringConverter
	org.springframework.core.convert.support.FallbackObjectToStringConverter
	org.springframework.core.convert.support.IdToEntityConverter
	org.springframework.core.convert.support.MapToMapConverter
	org.springframework.core.convert.support.ObjectToArrayConverter
	org.springframework.core.convert.support.ObjectToCollectionConverter
	org.springframework.core.convert.support.ObjectToOptionalConverter
	org.springframework.core.convert.support.StreamConverter
	org.springframework.core.convert.support.StreamConverter
	org.springframework.core.convert.support.StreamConverter
	org.springframework.core.convert.support.StreamConverter
	org.springframework.core.convert.support.StringToArrayConverter
	org.springframework.core.convert.support.StringToCollectionConverter

Example Project

Dependencies and Technologies Used:

• spring-context 6.1.2 (Spring Context)
   Version Compatibility: 4.0.7.RELEASE - 6.1.2Version List
  ×

  Version compatibilities of spring-context with this example:

  • 4.0.7.RELEASE
  • 4.0.8.RELEASE
  • 4.0.9.RELEASE
  • 4.1.0.RELEASE
  • 4.1.1.RELEASE
  • 4.1.2.RELEASE
  • 4.1.3.RELEASE
  • 4.1.4.RELEASE
  • 4.1.5.RELEASE
  • 4.1.6.RELEASE
  • 4.1.7.RELEASE
  • 4.1.8.RELEASE
  • 4.1.9.RELEASE
  • 4.2.0.RELEASE
  • 4.2.1.RELEASE
  • 4.2.2.RELEASE
  • 4.2.3.RELEASE
  • 4.2.4.RELEASE
  • 4.2.5.RELEASE
  • 4.2.6.RELEASE
  • 4.2.7.RELEASE
  • 4.2.8.RELEASE
  • 4.2.9.RELEASE
  • 4.3.0.RELEASE
  • 4.3.1.RELEASE
  • 4.3.2.RELEASE
  • 4.3.3.RELEASE
  • 4.3.4.RELEASE
  • 4.3.5.RELEASE
  • 4.3.6.RELEASE
  • 4.3.7.RELEASE
  • 4.3.8.RELEASE
  • 4.3.9.RELEASE
  • 4.3.10.RELEASE
  • 4.3.11.RELEASE
  • 4.3.12.RELEASE
  • 4.3.13.RELEASE
  • 4.3.14.RELEASE
  • 4.3.15.RELEASE
  • 4.3.16.RELEASE
  • 4.3.17.RELEASE
  • 4.3.18.RELEASE
  • 4.3.19.RELEASE
  • 4.3.20.RELEASE
  • 4.3.21.RELEASE
  • 4.3.22.RELEASE
  • 4.3.23.RELEASE
  • 4.3.24.RELEASE
  • 4.3.25.RELEASE
  • 4.3.26.RELEASE
  • 4.3.27.RELEASE
  • 4.3.28.RELEASE
  • 4.3.29.RELEASE
  • 4.3.30.RELEASE
  • 5.0.0.RELEASE
  • 5.0.1.RELEASE
  • 5.0.2.RELEASE
  • 5.0.3.RELEASE
  • 5.0.4.RELEASE
  • 5.0.5.RELEASE
  • 5.0.6.RELEASE
  • 5.0.7.RELEASE
  • 5.0.8.RELEASE
  • 5.0.9.RELEASE
  • 5.0.10.RELEASE
  • 5.0.11.RELEASE
  • 5.0.12.RELEASE
  • 5.0.13.RELEASE
  • 5.0.14.RELEASE
  • 5.0.15.RELEASE
  • 5.0.16.RELEASE
  • 5.0.17.RELEASE
  • 5.0.18.RELEASE
  • 5.0.19.RELEASE
  • 5.0.20.RELEASE
  • 5.1.0.RELEASE
  • 5.1.1.RELEASE
  • 5.1.2.RELEASE
  • 5.1.3.RELEASE
  • 5.1.4.RELEASE
  • 5.1.5.RELEASE
  • 5.1.6.RELEASE
  • 5.1.7.RELEASE
  • 5.1.8.RELEASE
  • 5.1.9.RELEASE
  • 5.1.10.RELEASE
  • 5.1.11.RELEASE
  • 5.1.12.RELEASE
  • 5.1.13.RELEASE
  • 5.1.14.RELEASE
  • 5.1.15.RELEASE
  • 5.1.16.RELEASE
  • 5.1.17.RELEASE
  • 5.1.18.RELEASE
  • 5.1.19.RELEASE
  • 5.1.20.RELEASE
  • 5.2.0.RELEASE
  • 5.2.1.RELEASE
  • 5.2.2.RELEASE
  • 5.2.3.RELEASE
  • 5.2.4.RELEASE
  • 5.2.5.RELEASE
  • 5.2.6.RELEASE
  • 5.2.7.RELEASE
  • 5.2.8.RELEASE
  • 5.2.9.RELEASE
  • 5.2.10.RELEASE
  • 5.2.11.RELEASE
  • 5.2.12.RELEASE
  • 5.2.13.RELEASE
  • 5.2.14.RELEASE
  • 5.2.15.RELEASE
  • 5.2.16.RELEASE
  • 5.2.17.RELEASE
  • 5.2.18.RELEASE
  • 5.2.19.RELEASE
  • 5.2.20.RELEASE
  • 5.2.21.RELEASE
  • 5.2.22.RELEASE
  • 5.2.23.RELEASE
  • 5.2.24.RELEASE
  • 5.2.25.RELEASE
  • 5.3.0
  • 5.3.1
  • 5.3.2
  • 5.3.3
  • 5.3.4
  • 5.3.5
  • 5.3.6
  • 5.3.7
  • 5.3.8
  • 5.3.9
  • 5.3.10
  • 5.3.11
  • 5.3.12
  • 5.3.13
  • 5.3.14
  • 5.3.15
  • 5.3.16
  • 5.3.17
  • 5.3.18
  • 5.3.19
  • 5.3.20
  • 5.3.21
  • 5.3.22
  • 5.3.23
  • 5.3.24
  • 5.3.25
  • 5.3.26
  • 5.3.27
  • 5.3.28
  • 5.3.29
  • 5.3.30
  • 5.3.31
  Compatible Java Version: 17+
  • 6.0.0
  • 6.0.1
  • 6.0.2
  • 6.0.3
  • 6.0.4
  • 6.0.5
  • 6.0.6
  • 6.0.7
  • 6.0.8
  • 6.0.9
  • 6.0.10
  • 6.0.11
  • 6.0.12
  • 6.0.13
  • 6.0.14
  • 6.0.15
  • 6.1.0
  • 6.1.1
  • 6.1.2

  Versions in green have been tested.

• JDK 17
• Maven 3.8.1