io.github.benas.randombeans.util

Class ReflectionUtils

java.lang.Object

io.github.benas.randombeans.util.ReflectionUtils

public class ReflectionUtils
extends java.lang.Object

Reflection utility methods.

Author:

Mahmoud Ben Hassine (mahmoud.benhassine@icloud.com)

Constructor Summary

Constructors

Constructor and Description
ReflectionUtils()

Method Summary

Modifier and Type	Method and Description
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.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.
java.lang.Class<?>	getWrapperType(java.lang.Class<?> primitiveType) Get wrapper type of a primitive type.
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	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	setProperty(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.

Methods inherited from class java.lang.Object

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

Constructor Detail

ReflectionUtils

public ReflectionUtils()

Method Detail

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

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 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.

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.

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)