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(Class<?> sourceType, Class<?> targetType) Return true if the type converter can convert the specified type to the desired target type.
Object	convertValue(Object value, TypeDescriptor typeDescriptor) Convert (may coerce) a value from one type to another, for example from a boolean to a string.

Method Detail

canConvert

boolean canConvert(Class<?> sourceType,
                   Class<?> targetType)

Return true if the type converter can convert the specified type to the desired target type.

Parameters:

sourceType - the type to be converted from

targetType - the type to be converted to

Returns:

true if that conversion can be performed

convertValue

Object convertValue(Object value,
                    TypeDescriptor typeDescriptor)
                    throws EvaluationException

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 for example, rather than simply a List.

Parameters:

value - the value to be converted

typeDescriptor - a type descriptor that supplies extra information about the requested result type

Returns:

the converted value

Throws:

EvaluationException - if conversion is not possible