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(org.springframework.core.convert.TypeDescriptor sourceType, org.springframework.core.convert.TypeDescriptor targetType)
    Return true if the type converter can convert the specified type to the desired target type.
    Object
    convertValue(Object value, org.springframework.core.convert.TypeDescriptor sourceType, org.springframework.core.convert.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 org.springframework.core.convert.TypeDescriptor sourceType, org.springframework.core.convert.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 org.springframework.core.convert.TypeDescriptor sourceType, org.springframework.core.convert.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