Package io.micronaut.core.convert

Interface TypeConverter<S,T>

Type Parameters:
S - The source type
T - The target type
All Known Subinterfaces:
FormattingTypeConverter<S,T,A>
All Known Implementing Classes:
CharSequenceToEnumConverter, CorsOriginConverter, MultiValuesConverterFactory.AbstractConverterToMultiValues, MultiValuesConverterFactory.IterableToMultiValuesConverter, MultiValuesConverterFactory.MapToMultiValuesConverter, MultiValuesConverterFactory.MultiValuesToIterableConverter, MultiValuesConverterFactory.MultiValuesToMapConverter, MultiValuesConverterFactory.MultiValuesToObjectConverter, MultiValuesConverterFactory.ObjectToMultiValuesConverter, ReadableBytesTypeConverter, SameSiteConverter
@Indexed(TypeConverter.class) public interface TypeConverter<S,T>

A type converter for converting from one type to another.

Implementations should be stateless, simple and thread safe. Type converters are often best defined as Java lambdas. You should NOT perform any overly complex, blocking or slow conversions in implementations of this interface.

If dependency injection is required, carefully consider what you inject. Databases and I/O bound interfaces are not good candidates. In addition, injecting dependencies that may trigger the evaluation of beans that depend on configuration will cause problems because all type converters have not been registered yet.

Since:
1.0
Author:
Graeme Rocher

  • Method Summary

    Modifier and Type
    Method
    Description
    default Optional<T>
    convert(S object, Class<T> targetType)
    Converts from the given source object type to the target type.
    Optional<T>
    convert(S object, Class<T> targetType, ConversionContext context)
    Converts from the given source object type to the target type.
    static <ST, TT> TypeConverter<ST,TT>
    of(Class<ST> sourceType, Class<TT> targetType, Function<ST,TT> converter)
    Creates a new TypeConverter for the give source type, target type and conversion function.

  • Method Details

    • convert

      default Optional<T> convert(S object, Class<T> targetType)
      Converts from the given source object type to the target type.
      Parameters:
      object - The object type
      targetType - The target type being converted to
      Returns:
      The converted type or empty if the conversion is not possible

    • convert

      Optional<T> convert(S object, Class<T> targetType, ConversionContext context)
      Converts from the given source object type to the target type. Implementers should take care to return Optional.empty() in case the object is not convertible by catching any necessary exceptions and failing gracefully.
      Parameters:
      object - The object type
      targetType - The target type being converted to
      context - The ConversionContext
      Returns:
      The converted type or empty if the conversion is not possible

    • of

      static <ST, TT> TypeConverter<ST,TT> of(Class<ST> sourceType, Class<TT> targetType, Function<ST,TT> converter)
      Creates a new TypeConverter for the give source type, target type and conversion function.
      Type Parameters:
      ST - The source generic type
      TT - The target generic type
      Parameters:
      sourceType - The source type
      targetType - The target type
      converter - The converter function
      Returns:
      The converter instance