org.jeasy.random.util

Class ReflectionUtils

java.lang.Object

org.jeasy.random.util.ReflectionUtils

public final class ReflectionUtils
extends java.lang.Object

Reflection utility methods. This class is intended for internal use only. All public methods (except asRandomizer(java.util.function.Supplier) might change between minor versions without notice.

Author:

Mahmoud Ben Hassine ([email protected])

Method Summary

Modifier and Type	Method and Description
static <T> Randomizer<T>	asRandomizer(java.util.function.Supplier<T> supplier) Create a dynamic proxy that adapts the given Supplier to a Randomizer.
static java.util.Collection<?>	createEmptyCollectionForType(java.lang.Class<?> fieldType, int initialSize) Create an empty collection for the given type.
static java.util.List<java.lang.Class<?>>	filterSameParameterizedTypes(java.util.List<java.lang.Class<?>> types, java.lang.reflect.Type type) Filters a list of types to keep only elements having the same parameterized types as the given type.
static <T extends java.lang.annotation.Annotation> T	getAnnotation(java.lang.reflect.Field field, java.lang.Class<T> annotationType) Looks for given annotationType on given field or read method for field.
static <T> java.util.List<java.lang.reflect.Field>	getDeclaredFields(T type) Get declared fields of a given type.
static java.util.Collection<?>	getEmptyImplementationForCollectionInterface(java.lang.Class<?> collectionInterface) Return an empty implementation for a Collection type.
static java.util.Map<?,?>	getEmptyImplementationForMapInterface(java.lang.Class<?> mapInterface) Return an empty implementation for the given Map interface.
static java.lang.Object	getFieldValue(java.lang.Object object, java.lang.reflect.Field field) Get the value (accessible or not accessible) of a field of a target object.
static java.util.List<java.lang.reflect.Field>	getInheritedFields(java.lang.Class<?> type) Get inherited fields of a given type.
static <T> java.util.List<java.lang.Class<?>>	getPublicConcreteSubTypesOf(java.lang.Class<T> type) Searches the classpath for all public concrete subtypes of the given interface or abstract class.
static java.util.Optional<java.lang.reflect.Method>	getReadMethod(java.lang.reflect.Field field) Get the read method for given field.
static java.lang.Class<?>	getWrapperType(java.lang.Class<?> primitiveType) Get wrapper type of a primitive type.
static java.util.Optional<java.lang.reflect.Method>	getWriteMethod(java.lang.reflect.Field field) Get the write method for given field.
static <T> boolean	isAbstract(java.lang.Class<T> type) Check if the type is abstract (either an interface or an abstract class).
static boolean	isAnnotationPresent(java.lang.reflect.Field field, java.lang.Class<? extends java.lang.annotation.Annotation> annotationType) Checks if field or corresponding read method is annotated with given annotationType.
static boolean	isArrayType(java.lang.Class<?> type) Check if a type is an array type.
static boolean	isCollectionType(java.lang.Class<?> type) Check if a type is a collection type.
static boolean	isCollectionType(java.lang.reflect.Type type) Check if a type is a collection type.
static boolean	isEnumType(java.lang.Class<?> type) Check if a type is an enum type.
static boolean	isInterface(java.lang.Class<?> type) Check if a type is an interface.
static boolean	isIntrospectable(java.lang.Class<?> type) Check if a type should be introspected for internal fields.
static boolean	isJdkBuiltIn(java.lang.Class<?> type) Check if a type is a JDK built-in collection/map.
static boolean	isMapType(java.lang.Class<?> type) Check if a type is a map type.
static boolean	isOptionalType(java.lang.Class<?> type) Check if a type is Optional.
static boolean	isParameterizedType(java.lang.reflect.Type type) Check if a type is a parameterized type
static boolean	isPopulatable(java.lang.reflect.Type type) Check if a type is populatable.
static boolean	isPrimitiveFieldWithDefaultValue(java.lang.Object object, java.lang.reflect.Field field) Check if a field has a primitive type and matching default value which is set by the compiler.
static <T> boolean	isPublic(java.lang.Class<T> type) Check if the type is public.
static boolean	isStatic(java.lang.reflect.Field field) Check if a field is static.
static boolean	isTypeVariable(java.lang.reflect.Type type) Check if a type is a type variable
static boolean	isWildcardType(java.lang.reflect.Type type) Check if a type is a wildcard type
static <T> Randomizer<T>	newInstance(java.lang.Class<T> type, RandomizerArgument[] randomizerArguments)
static void	setFieldValue(java.lang.Object object, java.lang.reflect.Field field, java.lang.Object value) Set a value (accessible or not accessible) in a field of a target object.
static void	setProperty(java.lang.Object object, java.lang.reflect.Field field, java.lang.Object value) Set a value in a field of a target object.

Methods inherited from class java.lang.Object

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

Method Detail

asRandomizer

public static <T> Randomizer<T> asRandomizer(java.util.function.Supplier<T> supplier)

Create a dynamic proxy that adapts the given Supplier to a Randomizer.

Type Parameters:

T - target type

Parameters:

supplier - to adapt

Returns:

the proxy randomizer

getDeclaredFields

public static <T> java.util.List<java.lang.reflect.Field> getDeclaredFields(T type)

Get declared fields of a given type.

Type Parameters:

T - the actual type to introspect

Parameters:

type - the type to introspect

Returns:

list of declared fields

getInheritedFields

public static java.util.List<java.lang.reflect.Field> getInheritedFields(java.lang.Class<?> type)

Get inherited fields of a given type.

Parameters:

type - the type to introspect

Returns:

list of inherited fields

setProperty

public static void setProperty(java.lang.Object object,
                               java.lang.reflect.Field field,
                               java.lang.Object value)
                        throws java.lang.IllegalAccessException,
                               java.lang.reflect.InvocationTargetException

Set a value in a field of a target object. If the target object provides a setter for the field, this setter will be used. Otherwise, the field will be set using reflection.

Parameters:

object - instance to set the property on

field - field to set the property on

value - value to set

Throws:

java.lang.IllegalAccessException - if the property cannot be set

java.lang.reflect.InvocationTargetException

setFieldValue

public static void setFieldValue(java.lang.Object object,
                                 java.lang.reflect.Field field,
                                 java.lang.Object value)
                          throws java.lang.IllegalAccessException

Set a value (accessible or not accessible) in a field of a target object.

Parameters:

object - instance to set the property on

field - field to set the property on

value - value to set

Throws:

java.lang.IllegalAccessException - if the property cannot be set

getFieldValue

public static java.lang.Object getFieldValue(java.lang.Object object,
                                             java.lang.reflect.Field field)
                                      throws java.lang.IllegalAccessException

Get the value (accessible or not accessible) of a field of a target object.

Parameters:

object - instance to get the field of

field - field to get the value of

Returns:

the value of the field

Throws:

java.lang.IllegalAccessException - if field can not be accessed

getWrapperType

public static java.lang.Class<?> getWrapperType(java.lang.Class<?> primitiveType)

Get wrapper type of a primitive type.

Parameters:

primitiveType - to get its wrapper type

Returns:

the wrapper type of the given primitive type

isPrimitiveFieldWithDefaultValue

public static boolean isPrimitiveFieldWithDefaultValue(java.lang.Object object,
                                                       java.lang.reflect.Field field)
                                                throws java.lang.IllegalAccessException

Check if a field has a primitive type and matching default value which is set by the compiler.

Parameters:

object - instance to get the field value of

field - field to check

Returns:

true if the field is primitive and is set to the default value, false otherwise

Throws:

java.lang.IllegalAccessException - if field cannot be accessed

isStatic

public static boolean isStatic(java.lang.reflect.Field field)

Check if a field is static.

Parameters:

field - the field to check

Returns:

true if the field is static, false otherwise

isInterface

public static boolean isInterface(java.lang.Class<?> type)

Check if a type is an interface.

Parameters:

type - the type to check

Returns:

true if the type is an interface, false otherwise

isAbstract

public static <T> boolean isAbstract(java.lang.Class<T> type)

Check if the type is abstract (either an interface or an abstract class).

Type Parameters:

T - the actual type to check

Parameters:

type - the type to check

Returns:

true if the type is abstract, false otherwise

isPublic

public static <T> boolean isPublic(java.lang.Class<T> type)

Check if the type is public.

Type Parameters:

T - the actual type to check

Parameters:

type - the type to check

Returns:

true if the type is public, false otherwise

isArrayType

public static boolean isArrayType(java.lang.Class<?> type)

Check if a type is an array type.

Parameters:

type - the type to check.

Returns:

true if the type is an array type, false otherwise.

isEnumType

public static boolean isEnumType(java.lang.Class<?> type)

Check if a type is an enum type.

Parameters:

type - the type to check.

Returns:

true if the type is an enum type, false otherwise.

isCollectionType

public static boolean isCollectionType(java.lang.Class<?> type)

Check if a type is a collection type.

Parameters:

type - the type to check.

Returns:

true if the type is a collection type, false otherwise

isCollectionType

public static boolean isCollectionType(java.lang.reflect.Type type)

Check if a type is a collection type.

Parameters:

type - the type to check.

Returns:

true if the type is a collection type, false otherwise

isPopulatable

public static boolean isPopulatable(java.lang.reflect.Type type)

Check if a type is populatable.

Parameters:

type - the type to check

Returns:

true if the type is populatable, false otherwise

isIntrospectable

public static boolean isIntrospectable(java.lang.Class<?> type)

Check if a type should be introspected for internal fields.

Parameters:

type - the type to check

Returns:

true if the type should be introspected, false otherwise

isMapType

public static boolean isMapType(java.lang.Class<?> type)

Check if a type is a map type.

Parameters:

type - the type to check

Returns:

true if the type is a map type, false otherwise.

isOptionalType

public static boolean isOptionalType(java.lang.Class<?> type)

Check if a type is Optional.

Parameters:

type - the type to check

Returns:

true if the type is Optional, false otherwise.

isJdkBuiltIn

public static boolean isJdkBuiltIn(java.lang.Class<?> type)

Check if a type is a JDK built-in collection/map.

Parameters:

type - the type to check

Returns:

true if the type is a built-in collection/map type, false otherwise.

isParameterizedType

public static boolean isParameterizedType(java.lang.reflect.Type type)

Check if a type is a parameterized type

Parameters:

type - the type to check

Returns:

true if the type is parameterized, false otherwise

isWildcardType

public static boolean isWildcardType(java.lang.reflect.Type type)

Check if a type is a wildcard type

Parameters:

type - the type to check

Returns:

true if the type is a wildcard type, false otherwise

isTypeVariable

public static boolean isTypeVariable(java.lang.reflect.Type type)

Check if a type is a type variable

Parameters:

type - the type to check

Returns:

true if the type is a type variable, false otherwise

getPublicConcreteSubTypesOf

public static <T> java.util.List<java.lang.Class<?>> getPublicConcreteSubTypesOf(java.lang.Class<T> type)

Searches the classpath for all public concrete subtypes of the given interface or abstract class.

Type Parameters:

T - the actual type to introspect

Parameters:

type - to search concrete subtypes of

Returns:

a list of all concrete subtypes found

filterSameParameterizedTypes

public static java.util.List<java.lang.Class<?>> filterSameParameterizedTypes(java.util.List<java.lang.Class<?>> types,
                                                                              java.lang.reflect.Type type)

Filters a list of types to keep only elements having the same parameterized types as the given type.

Parameters:

type - the type to use for the search

types - a list of types to filter

Returns:

a list of types having the same parameterized types as the given type

getAnnotation

public static <T extends java.lang.annotation.Annotation> T getAnnotation(java.lang.reflect.Field field,
                                                                          java.lang.Class<T> annotationType)

Looks for given annotationType on given field or read method for field.

Type Parameters:

T - the actual type of annotation

Parameters:

field - field to check

annotationType - Type of annotation you're looking for.

Returns:

given annotation if field or read method has this annotation or null.

isAnnotationPresent

public static boolean isAnnotationPresent(java.lang.reflect.Field field,
                                          java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)

Checks if field or corresponding read method is annotated with given annotationType.

Parameters:

field - Field to check

annotationType - Annotation you're looking for.

Returns:

true if field or read method it annotated with given annotationType or false.

getEmptyImplementationForCollectionInterface

public static java.util.Collection<?> getEmptyImplementationForCollectionInterface(java.lang.Class<?> collectionInterface)

Return an empty implementation for a Collection type.

Parameters:

collectionInterface - for which an empty implementation should be returned

Returns:

empty implementation for the collection interface

createEmptyCollectionForType

public static java.util.Collection<?> createEmptyCollectionForType(java.lang.Class<?> fieldType,
                                                                   int initialSize)

Create an empty collection for the given type.

Parameters:

fieldType - for which an empty collection should we created

initialSize - initial size of the collection

Returns:

empty collection

getEmptyImplementationForMapInterface

public static java.util.Map<?,?> getEmptyImplementationForMapInterface(java.lang.Class<?> mapInterface)

Return an empty implementation for the given Map interface.

Parameters:

mapInterface - for which an empty implementation should be returned

Returns:

empty implementation for the given Map interface.

getWriteMethod

public static java.util.Optional<java.lang.reflect.Method> getWriteMethod(java.lang.reflect.Field field)

Get the write method for given field.

Parameters:

field - field to get the write method for

Returns:

Optional of write method or empty if field has no write method

getReadMethod

public static java.util.Optional<java.lang.reflect.Method> getReadMethod(java.lang.reflect.Field field)

Get the read method for given field.

Parameters:

field - field to get the read method for.

Returns:

Optional of read method or empty if field has no read method

newInstance

public static <T> Randomizer<T> newInstance(java.lang.Class<T> type,
                                            RandomizerArgument[] randomizerArguments)