Package org.springframework.expression

Interface TypeConverter

All Known Implementing Classes:
StandardTypeConverter
public interface TypeConverter
A type converter can convert values between different types encountered during expression evaluation. This is an SPI for the expression parser; see ConversionService for the primary user API to Spring's conversion facilities.
Since:
3.0
Author:
Andy Clement, Juergen Hoeller

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    canConvert(TypeDescriptor sourceType, TypeDescriptor targetType)
    Return true if the type converter can convert the specified type to the desired target type.
    Object
    convertValue(Object value, TypeDescriptor sourceType, TypeDescriptor targetType)
    Convert (or coerce) a value from one type to another, for example from a boolean to a String.

  • Method Details

    • canConvert

      boolean canConvert(@Nullable TypeDescriptor sourceType, TypeDescriptor targetType)
      Return true if the type converter can convert the specified type to the desired target type.
      Parameters:
      sourceType - a type descriptor that describes the source type
      targetType - a type descriptor that describes the requested result type
      Returns:
      true if that conversion can be performed

    • convertValue

      @Nullable Object convertValue(@Nullable Object value, @Nullable TypeDescriptor sourceType, TypeDescriptor targetType)
      Convert (or coerce) a value from one type to another, for example from a boolean to a String.

      The TypeDescriptor parameters enable support for typed collections: A caller may prefer a List<Integer>, for example, rather than simply any List.

      Parameters:
      value - the value to be converted
      sourceType - a type descriptor that supplies extra information about the source object
      targetType - a type descriptor that supplies extra information about the requested result type
      Returns:
      the converted value
      Throws:
      EvaluationException - if conversion failed or is not possible to begin with