Class Reflections
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Field Summary
Modifier and TypeFieldDescriptionstatic final Annotation[]
An empty array of typeAnnotation
, useful converting lists to arrays.static final Class<?>[]
static final Object[]
An empty array of typeObject
, useful for converting lists to arrays.static final Type[]
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Method Summary
Modifier and TypeMethodDescriptionbuildTypeMap
(Set<Type> types) static <T> T
Perform a runtime cast.static <T> Class<T>
classForName
(String name, ClassLoader... loaders) Loads and initializes a class for the given name.static boolean
containsWildcards
(Type[] types) static Constructor<?>
findDeclaredConstructor
(Class<?> clazz, Class<?>... args) Search the class hierarchy for a constructor with the given arguments.static Field
findDeclaredField
(Class<?> clazz, String name) Search the class hierarchy for a field with the given name.static Method
findDeclaredMethod
(Class<?> clazz, String name, Class<?>... args) Search the class hierarchy for a method with the given name and arguments.static Set<Constructor<?>>
getAllDeclaredConstructors
(Class<?> clazz) Get all the declared constructors on the class hierarchy.getAllDeclaredFields
(Class<?> clazz) Get all the declared fields on the class hierarchy.getAllDeclaredMethods
(Class<?> clazz) Get all the declared methods on the class hierarchy.static Set<Annotation>
getAnnotationsWithMetaAnnotation
(Set<Annotation> annotations, Class<? extends Annotation> metaAnnotationType) Search for annotations with the specified meta annotation typestatic Object
getFieldValue
(Field field, Object instance) static <T> T
getFieldValue
(Field field, Object instance, Class<T> expectedType) Get the value of the field, on the specified instance, casting the value of the field to the expected type.static Class<?>
getMemberType
(Member member) Get the type of the memberstatic int
getNesting
(Class<?> clazz) static Object
getNonPrivateFinalMethodOrType
(Class<?> type) static String
getPropertyName
(Method method) Gets the property name from a getter method.static <T> Class<T>
getRawType
(Type type) Extract the raw type, given a type.static <T> T
invokeMethod
(boolean setAccessible, Method method, Class<T> expectedReturnType, Object instance, Object... args) Invoke the method on the instance, with any arguments specified, casting the result of invoking the method to the expected return type.static Object
invokeMethod
(boolean setAccessible, Method method, Object instance, Object... args) Invoke the specified method on the provided instance, passing any additional arguments included in this method as arguments to the specified method.static <T> T
invokeMethod
(Method method, Class<T> expectedReturnType, Object instance, Object... args) Invoke the specified method on the provided instance, passing any additional arguments included in this method as arguments to the specified method.static Object
invokeMethod
(Method method, Object instance, Object... args) Invoke the specified method on the provided instance, passing any additional arguments included in this method as arguments to the specified method.static boolean
isAbstract
(Method method) Checks if a method is abstractstatic boolean
isArrayType
(Class<?> rawType) Checks if raw type is array typestatic boolean
isAssignableFrom
(Class<?> rawType1, Type[] actualTypeArguments1, Class<?> rawType2, Type[] actualTypeArguments2) Check the assignability of one type to another, taking into account the actual type arguementsstatic boolean
isAssignableFrom
(Class<?> rawType1, Type[] actualTypeArguments1, Type type2) static boolean
isAssignableFrom
(Type[] types1, Type type2) static boolean
isAssignableFrom
(Type[] actualTypeArguments1, Type[] actualTypeArguments2) static boolean
isAssignableFrom
(Type type1, Type type2) static boolean
isAssignableFrom
(Type type1, Type[] types2) static boolean
isAssignableFrom
(Type type1, Set<? extends Type> types2) static boolean
isAssignableFrom
(Set<Type> types1, Type type2) Check the assignability of a set of flattened types.static boolean
isAssignableFrom
(Set<Type> types1, Set<Type> types2) Check the assiginability of a set of flattened types.static boolean
isCacheable
(Annotation[] annotations) static boolean
isCacheable
(Set<Annotation> annotations) static boolean
Checks if class is finalstatic boolean
Checks if member is finalstatic boolean
isPackagePrivate
(int mod) static boolean
isParamerterizedTypeWithWildcard
(Class<?> type) static boolean
isParameterizedType
(Class<?> type) Checks if type is parameterized typestatic boolean
isPrimitive
(Type type) static boolean
Checks if member is privatestatic boolean
isSerializable
(Class<?> clazz) Check if a class is serializable.static boolean
Checks if type is staticstatic boolean
Checks if member is staticstatic boolean
isTransient
(Member member) static boolean
isTypeBounded
(Type type, Type[] lowerBounds, Type[] upperBounds) static boolean
isTypeOrAnyMethodFinal
(Class<?> type) Checks if type or member is finalstatic boolean
matches
(Class<?> rawType1, Type[] actualTypeArguments1, Class<?> rawType2, Type[] actualTypeArguments2) static boolean
static boolean
static boolean
static boolean
Check whether whether any of the types1 matches a type in types2static boolean
methodExists
(Class<?> clazz, String name) Determine if a method exists in a specified class hierarchystatic <T> T
newInstance
(Class<?> type, String fullQualifiedName) Creates a new instance of a class given itsfullQualifiedName
.static <T> T
newInstance
(Class<T> fromClass) Creates a new instance of a class.static Class<?>
resolveListType
(Field field, Object instance) static <A extends AccessibleObject>
AsetAccessible
(A member) Set the accessibility flag on theAccessibleObject
as described inAccessibleObject.setAccessible(boolean)
within the context of a {link PrivilegedAction}.static <A extends AccessibleObject>
AunsetAccessible
(A member) Set the accessibility flag on theAccessibleObject
to false as described inAccessibleObject.setAccessible(boolean)
within the context of a {link PrivilegedAction}.
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Field Details
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EMPTY_ANNOTATION_ARRAY
An empty array of typeAnnotation
, useful converting lists to arrays. -
EMPTY_OBJECT_ARRAY
An empty array of typeObject
, useful for converting lists to arrays. -
EMPTY_TYPES
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EMPTY_CLASSES
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Method Details
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cast
Perform a runtime cast. Similar to
Class.cast(Object)
, but useful when you do not have aClass
object for type you wish to cast to.Class.cast(Object)
should be used if possible- Type Parameters:
T
- the type to cast to- Parameters:
obj
- the object to perform the cast on- Returns:
- the casted object
- Throws:
ClassCastException
- if the type T is not a subtype of the object- See Also:
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getAllDeclaredFields
Get all the declared fields on the class hierarchy. This will return overridden fields.- Parameters:
clazz
- The class to search- Returns:
- the set of all declared fields or an empty set if there are none
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findDeclaredField
Search the class hierarchy for a field with the given name. Will return the nearest match, starting with the class specified and searching up the hierarchy.- Parameters:
clazz
- The class to searchname
- The name of the field to search for- Returns:
- The field found, or null if no field is found
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getAnnotationsWithMetaAnnotation
public static Set<Annotation> getAnnotationsWithMetaAnnotation(Set<Annotation> annotations, Class<? extends Annotation> metaAnnotationType) Search for annotations with the specified meta annotation type- Parameters:
annotations
- The annotation set to searchmetaAnnotationType
- The type of the meta annotation to search for- Returns:
- The set of annotations with the specified meta annotation, or an empty set if none are found
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methodExists
Determine if a method exists in a specified class hierarchy- Parameters:
clazz
- The class to searchname
- The name of the method- Returns:
- true if a method is found, otherwise false
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getAllDeclaredMethods
Get all the declared methods on the class hierarchy. This will return overridden methods.- Parameters:
clazz
- The class to search- Returns:
- the set of all declared methods or an empty set if there are none
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findDeclaredMethod
Search the class hierarchy for a method with the given name and arguments. Will return the nearest match, starting with the class specified and searching up the hierarchy.- Parameters:
clazz
- The class to searchname
- The name of the method to search forargs
- The arguments of the method to search for- Returns:
- The method found, or null if no method is found
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findDeclaredConstructor
Search the class hierarchy for a constructor with the given arguments. Will return the nearest match, starting with the class specified and searching up the hierarchy.- Parameters:
clazz
- The class to searchargs
- The arguments of the constructor to search for- Returns:
- The constructor found, or null if no constructor is found
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getAllDeclaredConstructors
Get all the declared constructors on the class hierarchy. This will return overridden constructors.- Parameters:
clazz
- The class to search- Returns:
- the set of all declared constructors or an empty set if there are none
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getMemberType
Get the type of the member- Parameters:
member
- The member- Returns:
- The type of the member
- Throws:
UnsupportedOperationException
- if the member is not a field, method, or constructor
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classForName
public static <T> Class<T> classForName(String name, ClassLoader... loaders) throws ClassNotFoundException Loads and initializes a class for the given name.
If the Thread Context Class Loader is available, it will be used, otherwise the classloader used to load
Reflections
will be usedIt is also possible to specify additional classloaders to attempt to load the class with. If the first attempt fails, then these additional loaders are tried in order.
- Parameters:
name
- the name of the class to loadloaders
- additional classloaders to use to attempt to load the class- Returns:
- the class object
- Throws:
ClassNotFoundException
- if the class cannot be found
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invokeMethod
Invoke the specified method on the provided instance, passing any additional arguments included in this method as arguments to the specified method.
This method provides the same functionality and throws the same exceptions as
invokeMethod(boolean, Method, Class, Object, Object...)
, with the expected return type set toObject
and no change to the method's accessibility. -
invokeMethod
public static Object invokeMethod(boolean setAccessible, Method method, Object instance, Object... args) Invoke the specified method on the provided instance, passing any additional arguments included in this method as arguments to the specified method.
This method attempts to set the accessible flag of the method in a {link PrivilegedAction} before invoking the method if the first argument is true.
This method provides the same functionality and throws the same exceptions as
invokeMethod(boolean, Method, Class, Object, Object...)
, with the expected return type set toObject
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invokeMethod
public static <T> T invokeMethod(Method method, Class<T> expectedReturnType, Object instance, Object... args) Invoke the specified method on the provided instance, passing any additional arguments included in this method as arguments to the specified method.
This method provides the same functionality and throws the same exceptions as
invokeMethod(boolean, Method, Class, Object, Object...)
, with the expected return type set toObject
and honoring the accessibility of the method. -
invokeMethod
public static <T> T invokeMethod(boolean setAccessible, Method method, Class<T> expectedReturnType, Object instance, Object... args) Invoke the method on the instance, with any arguments specified, casting the result of invoking the method to the expected return type.
This method wraps
Method.invoke(Object, Object...)
, converting the checked exceptions thatMethod.invoke(Object, Object...)
specifies to runtime exceptions.If instructed, this method attempts to set the accessible flag of the method in a {link PrivilegedAction} before invoking the method.
- Parameters:
setAccessible
- flag indicating whether method should first be set as accessiblemethod
- the method to invokeinstance
- the instance to invoke the methodargs
- the arguments to the method- Returns:
- the result of invoking the method, or null if the method's return type is void
- Throws:
RuntimeException
- if thisMethod
object enforces Java language access control and the underlying method is inaccessible or if the underlying method throws an exception or if the initialization provoked by this method fails.IllegalArgumentException
- if the method is an instance method and the specifiedinstance
argument is not an instance of the class or interface declaring the underlying method (or of a subclass or implementor thereof); if the number of actual and formal parameters differ; if an unwrapping conversion for primitive arguments fails; or if, after possible unwrapping, a parameter value cannot be converted to the corresponding formal parameter type by a method invocation conversion.NullPointerException
- if the specifiedinstance
is null and the method is an instance method.ClassCastException
- if the result of invoking the method cannot be cast to the expectedReturnTypeExceptionInInitializerError
- if the initialization provoked by this method fails.- See Also:
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setAccessible
Set the accessibility flag on theAccessibleObject
as described inAccessibleObject.setAccessible(boolean)
within the context of a {link PrivilegedAction}.- Type Parameters:
A
- member the accessible object type- Parameters:
member
- the accessible object- Returns:
- the accessible object after the accessible flag has been altered
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unsetAccessible
Set the accessibility flag on theAccessibleObject
to false as described inAccessibleObject.setAccessible(boolean)
within the context of a {link PrivilegedAction}.- Type Parameters:
A
- member the accessible object type- Parameters:
member
- the accessible object- Returns:
- the accessible object after the accessible flag has been altered
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getFieldValue
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getFieldValue
Get the value of the field, on the specified instance, casting the value of the field to the expected type.
This method wraps
Field.get(Object)
, converting the checked exceptions thatField.get(Object)
specifies to runtime exceptions.- Type Parameters:
T
- the type of the field's value- Parameters:
field
- the field to operate oninstance
- the instance from which to retrieve the valueexpectedType
- the expected type of the field's value- Returns:
- the value of the field
- Throws:
RuntimeException
- if the underlying field is inaccessible.IllegalArgumentException
- if the specifiedinstance
is not an instance of the class or interface declaring the underlying field (or a subclass or implementor thereof).NullPointerException
- if the specifiedinstance
is null and the field is an instance field.ExceptionInInitializerError
- if the initialization provoked by this method fails.
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getRawType
Extract the raw type, given a type.- Type Parameters:
T
- the type- Parameters:
type
- the type to extract the raw type from- Returns:
- the raw type, or null if the raw type cannot be determined.
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isSerializable
Check if a class is serializable.- Parameters:
clazz
- The class to check- Returns:
- true if the class implements serializable or is a primitive
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buildTypeMap
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isCacheable
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isCacheable
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getPropertyName
Gets the property name from a getter method. We extend JavaBean conventions, allowing the getter method to have parameters- Parameters:
method
- The getter method- Returns:
- The name of the property. Returns null if method wasn't JavaBean getter-styled
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isFinal
Checks if class is final- Parameters:
clazz
- The class to check- Returns:
- True if final, false otherwise
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getNesting
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isFinal
Checks if member is final- Parameters:
member
- The member to check- Returns:
- True if final, false otherwise
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isPrivate
Checks if member is private- Parameters:
member
- The member to check- Returns:
- True if final, false otherwise
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isTypeOrAnyMethodFinal
Checks if type or member is final- Parameters:
type
- Type or member- Returns:
- True if final, false otherwise
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getNonPrivateFinalMethodOrType
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isPackagePrivate
public static boolean isPackagePrivate(int mod) -
isStatic
Checks if type is static- Parameters:
type
- Type to check- Returns:
- True if static, false otherwise
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isStatic
Checks if member is static- Parameters:
member
- Member to check- Returns:
- True if static, false otherwise
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isTransient
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isAbstract
Checks if a method is abstract- Parameters:
method
-- Returns:
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isArrayType
Checks if raw type is array type- Parameters:
rawType
- The raw type to check- Returns:
- True if array, false otherwise
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isParameterizedType
Checks if type is parameterized type- Parameters:
type
- The type to check- Returns:
- True if parameterized, false otherwise
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isParamerterizedTypeWithWildcard
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containsWildcards
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isAssignableFrom
public static boolean isAssignableFrom(Class<?> rawType1, Type[] actualTypeArguments1, Class<?> rawType2, Type[] actualTypeArguments2) Check the assignability of one type to another, taking into account the actual type arguements- Parameters:
rawType1
- the raw type of the class to checkactualTypeArguments1
- the actual type arguements to check, or an empty array if not a parameterized typerawType2
- the raw type of the class to checkactualTypeArguments2
- the actual type arguements to check, or an empty array if not a parameterized type- Returns:
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matches
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isAssignableFrom
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isAssignableFrom
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matches
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isAssignableFrom
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isAssignableFrom
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matches
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isTypeBounded
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isAssignableFrom
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matches
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isAssignableFrom
Check the assiginability of a set of flattened types. This algorithm will check whether any of the types1 matches a type in types2- Parameters:
types1
-types2
-- Returns:
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matches
Check whether whether any of the types1 matches a type in types2- Parameters:
types1
-types2
-- Returns:
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isAssignableFrom
Check the assignability of a set of flattened types. This algorithm will check whether any of the types1 matches a type in types2- Parameters:
types1
-type2
-- Returns:
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isAssignableFrom
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isPrimitive
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newInstance
public static <T> T newInstance(Class<T> fromClass) throws ClassNotFoundException, IllegalAccessException, InstantiationException Creates a new instance of a class.
This method will use the same class loader of the given class to create the new instance.
- Parameters:
fromClass
- The class from where the instance should be created.- Returns:
- A newly allocated instance of the class.
- Throws:
ClassNotFoundException
IllegalAccessException
InstantiationException
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newInstance
public static <T> T newInstance(Class<?> type, String fullQualifiedName) throws ClassNotFoundException, IllegalAccessException, InstantiationException Creates a new instance of a class given its
fullQualifiedName
.This method will use the same class loader of
type
to create the new instance.- Parameters:
type
- The class that will be used to get the class loader from.fullQualifiedName
- The full qualified name of the class from which the instance will be created.- Returns:
- A newly allocated instance of the class.
- Throws:
ClassNotFoundException
IllegalAccessException
InstantiationException
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resolveListType
Resolves the type of items for a
Field
declared as aList
.This method will first try to check the parametrized type of the field type. If none is defined, it will try to infer the type of items by looking at the value of the field for the given
instance
.Make sure the field is accessible before invoking this method.
- Parameters:
field
- the field declared asList
instance
- the instance that should be used to obtain infer the type in case no parametrized type is found in the field.- Returns:
- if the field is not a
List
, it returns null. Otherwise the type of items of the list. If the type for items can not be inferred, theObject
type is returned. - Throws:
IllegalAccessException
- in case it fails to obtain the value of the field from theinstance
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