Interface ArgumentConverter

All Known Implementing Classes:

AnnotationBasedArgumentConverter, DefaultArgumentConverter, SimpleArgumentConverter, TypedArgumentConverter

@API(status=STABLE,
     since="5.7")
public interface ArgumentConverter

ArgumentConverter is an abstraction that allows an input object to be converted to an instance of a different class.

Such an ArgumentConverter is applied to the method parameter of a @ParameterizedTest or a constructor parameter or @Parameter-annotated field of a @ParameterizedClass with the help of a @ConvertWith annotation.

Implementations must provide a no-args constructor or a single unambiguous constructor to use parameter resolution. They should not make any assumptions regarding when they are instantiated or how often they are called. Since instances may potentially be cached and called from different threads, they should be thread-safe.

Extend SimpleArgumentConverter if your implementation only needs to know the target type and does not need access to the ParameterContext to perform the conversion.

Extend TypedArgumentConverter if your implementation always converts from a given source type into a given target type and does not need access to the ParameterContext to perform the conversion.

Since:

5.0

See Also:

• ParameterizedTest
• ConvertWith
• AnnotationConsumer
• SimpleArgumentConverter
• TypedArgumentConverter

Method Summary

Modifier and Type	Method	Description
@Nullable Object	convert(@Nullable Object source, ParameterContext context)	Convert the supplied source object according to the supplied context.
default @Nullable Object	convert(@Nullable Object source, FieldContext context)	Convert the supplied source object according to the supplied context.

Method Details

convert

@Nullable Object convert(@Nullable Object source,
 ParameterContext context)
                  throws ArgumentConversionException

Convert the supplied source object according to the supplied context.

Parameters:

source - the source object to convert; may be null

context - the parameter context where the converted object will be supplied; never null

Returns:

the converted object; may be null but only if the target type is a reference type

Throws:

ArgumentConversionException - if an error occurs during the conversion

convert

@API(status=EXPERIMENTAL,
     since="6.0")
default @Nullable Object convert(@Nullable Object source,
 FieldContext context)
                          throws ArgumentConversionException

Convert the supplied source object according to the supplied context.

Parameters:

source - the source object to convert; may be null

context - the field context where the converted object will be injected; never null

Returns:

the converted object; may be null but only if the target type is a reference type

Throws:

ArgumentConversionException - if an error occurs during the conversion

Since:

5.13