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
 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 (may coerce) a value from one type to another, for example from a boolean to a string.
 

Method Detail

canConvert

boolean canConvert(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

Object convertValue(Object value,
                    TypeDescriptor sourceType,
                    TypeDescriptor targetType)
Convert (may coerce) a value from one type to another, for example from a boolean to a string. The typeDescriptor parameter enables support for typed collections - if the caller really wishes they can have a List<Integer> for example, rather than simply a 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 is not possible