Package org.junit.jupiter.params.converter

Class FallbackStringToObjectConverter

java.lang.Object

org.junit.jupiter.params.converter.FallbackStringToObjectConverter

All Implemented Interfaces:

DefaultArgumentConverter.StringToObjectConverter

class FallbackStringToObjectConverter
extends Object
implements DefaultArgumentConverter.StringToObjectConverter

FallbackStringToObjectConverter is a DefaultArgumentConverter.StringToObjectConverter that provides a fallback conversion strategy for converting from a String to a given target type by invoking a static factory method or factory constructor defined in the target type.

Search Algorithm

1. Search for a single, non-private static factory method in the target type that converts from a String to the target type. Use the factory method if present.
2. Search for a single, non-private constructor in the target type that accepts a String. Use the constructor if present.

If multiple suitable factory methods are discovered they will be ignored. If neither a single factory method nor a single constructor is found, this converter acts as a no-op.

Since:

5.1

See Also:

• DefaultArgumentConverter

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	FallbackStringToObjectConverter.IsFactoryConstructor	Predicate that determines if the Constructor supplied to FallbackStringToObjectConverter.IsFactoryConstructor.test(Constructor) is a non-private factory constructor for the supplied FallbackStringToObjectConverter.IsFactoryConstructor.targetType.
(package private) static class	FallbackStringToObjectConverter.IsFactoryMethod	Predicate that determines if the Method supplied to FallbackStringToObjectConverter.IsFactoryMethod.test(Method) is a non-private static factory method for the supplied FallbackStringToObjectConverter.IsFactoryMethod.targetType.

Field Summary

Fields

Modifier and Type	Field	Description
private static final ConcurrentHashMap<Class<?>,Function<String,Object>>	factoryExecutableCache	Cache for factory methods and factory constructors.
private static final Function<String,Object>	NULL_EXECUTABLE	Implementation of the NULL Object Pattern.

Constructor Summary

Constructors

Constructor	Description
FallbackStringToObjectConverter()

Method Summary

Modifier and Type	Method	Description
boolean	canConvert(Class<?> targetType)
Object	convert(String source, Class<?> targetType)
private static Constructor<?>	findFactoryConstructor(Class<?> targetType)
private static Function<String,Object>	findFactoryExecutable(Class<?> targetType)
private static Method	findFactoryMethod(Class<?> targetType)
private static boolean	isNotPrivateAndAcceptsSingleStringArgument(Executable executable)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

NULL_EXECUTABLE

private static final Function<String,Object> NULL_EXECUTABLE

Implementation of the NULL Object Pattern.

factoryExecutableCache

private static final ConcurrentHashMap<Class<?>,Function<String,Object>> factoryExecutableCache

Cache for factory methods and factory constructors.

Searches that do not find a factory method or constructor are tracked by the presence of a NULL_EXECUTABLE object stored in the map. This prevents the framework from repeatedly searching for things which are already known not to exist.

Constructor Details

FallbackStringToObjectConverter

FallbackStringToObjectConverter()

Method Details

canConvert

public boolean canConvert(Class<?> targetType)

Specified by:

canConvert in interface DefaultArgumentConverter.StringToObjectConverter

convert

public Object convert(String source,
 Class<?> targetType)
               throws Exception

Specified by:

convert in interface DefaultArgumentConverter.StringToObjectConverter

Throws:

Exception

findFactoryExecutable

private static Function<String,Object> findFactoryExecutable(Class<?> targetType)

findFactoryMethod

private static Method findFactoryMethod(Class<?> targetType)

findFactoryConstructor

private static Constructor<?> findFactoryConstructor(Class<?> targetType)

isNotPrivateAndAcceptsSingleStringArgument

private static boolean isNotPrivateAndAcceptsSingleStringArgument(Executable executable)