org.dynalang.dynalink.linker

Interface GuardingTypeConverterFactory

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

public interface GuardingTypeConverterFactory

Optional interface that can be implemented by GuardingDynamicLinker implementations to provide language-runtime specific implicit type conversion capabilities. Note that if you implement this interface, you will very likely want to implement ConversionComparator interface too, as your additional language-specific conversions, in absence of a strategy for prioritizing these conversions, will cause more ambiguity in selecting the correct overload when trying to link to an overloaded POJO method.

Author:

Attila Szegedi

Method Summary

Modifier and Type	Method and Description
GuardedInvocation	convertToType(Class<?> sourceType, Class<?> targetType) Returns a guarded invocation that receives an Object of the specified source type and returns an Object converted to the specified target type.

Method Detail

convertToType

GuardedInvocation convertToType(Class<?> sourceType,
                              Class<?> targetType)
                                throws Exception

Returns a guarded invocation that receives an Object of the specified source type and returns an Object converted to the specified target type. The type of the invocation is targetType(sourceType), while the type of the guard is boolean(sourceType). Note that this will never be invoked for type conversions allowed by the JLS 5.3 "Method Invocation Conversion", see TypeUtilities.isMethodInvocationConvertible(Class, Class) for details. An implementation can assume it is never requested to produce a converter for these conversions.

Parameters:

sourceType - source type

targetType - the target type.

Returns:

a guarded invocation that can take an object (if it passes guard) and returns another object that is its representation coerced into the target type. In case the factory is certain it is unable to handle a conversion, it can return null. In case the factory is certain that it can always handle the conversion, it can return an unconditional invocation (one whose guard is null).

Throws:

Exception - if there was an error during creation of the converter