Package org.junit.platform.commons.util

Class ReflectionUtils

  • @API(status=INTERNAL,
     since="1.0")
public final class ReflectionUtils
extends java.lang.Object
    Collection of utilities for working with the Java reflection APIs.

    DISCLAIMER

    These utilities are intended solely for usage within the JUnit framework itself. Any usage by external parties is not supported. Use at your own risk!

    Some utilities are published via the maintained ReflectionSupport class.

    Since:
    1.0
    See Also:
    ReflectionSupport

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  ReflectionUtils.HierarchyTraversalMode
      Modes in which a hierarchy can be traversed — for example, when searching for methods or fields within a class hierarchy.

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      private ReflectionUtils()  

    • Method Summary

      All Methods Static Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      private static int defaultFieldSorter​(java.lang.reflect.Field field1, java.lang.reflect.Field field2)
      Field comparator inspired by JUnit 4's org.junit.internal.MethodSorter implementation.
      private static int defaultMethodSorter​(java.lang.reflect.Method method1, java.lang.reflect.Method method2)
      Method comparator based upon JUnit 4's org.junit.internal.MethodSorter implementation.
      private static void detectInnerClassCycle​(java.lang.Class<?> clazz)
      Detect a cycle in the inner class hierarchy in which the supplied class resides — from the supplied class up to the outermost enclosing class — and throw a JUnitException if a cycle is detected.
      static java.util.List<java.lang.Class<?>> findAllClassesInClasspathRoot​(java.net.URI root, java.util.function.Predicate<java.lang.Class<?>> classFilter, java.util.function.Predicate<java.lang.String> classNameFilter)  
      static java.util.List<java.lang.Class<?>> findAllClassesInClasspathRoot​(java.net.URI root, ClassFilter classFilter)  
      static java.util.List<java.lang.Class<?>> findAllClassesInModule​(java.lang.String moduleName, java.util.function.Predicate<java.lang.Class<?>> classFilter, java.util.function.Predicate<java.lang.String> classNameFilter)  
      static java.util.List<java.lang.Class<?>> findAllClassesInModule​(java.lang.String moduleName, ClassFilter classFilter)  
      static java.util.List<java.lang.Class<?>> findAllClassesInPackage​(java.lang.String basePackageName, java.util.function.Predicate<java.lang.Class<?>> classFilter, java.util.function.Predicate<java.lang.String> classNameFilter)  
      static java.util.List<java.lang.Class<?>> findAllClassesInPackage​(java.lang.String basePackageName, ClassFilter classFilter)  
      private static java.util.List<java.lang.reflect.Field> findAllFieldsInHierarchy​(java.lang.Class<?> clazz, ReflectionUtils.HierarchyTraversalMode traversalMode)  
      private static java.util.List<java.lang.reflect.Method> findAllMethodsInHierarchy​(java.lang.Class<?> clazz, ReflectionUtils.HierarchyTraversalMode traversalMode)
      Find all non-synthetic methods in the superclass and interface hierarchy, excluding Object.
      static java.util.List<java.lang.reflect.Constructor<?>> findConstructors​(java.lang.Class<?> clazz, java.util.function.Predicate<java.lang.reflect.Constructor<?>> predicate)
      Find all constructors in the supplied class that match the supplied predicate.
      static java.util.List<java.lang.reflect.Field> findFields​(java.lang.Class<?> clazz, java.util.function.Predicate<java.lang.reflect.Field> predicate, ReflectionUtils.HierarchyTraversalMode traversalMode)  
      static java.util.Optional<java.lang.reflect.Method> findMethod​(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.Class<?>... parameterTypes)  
      static java.util.Optional<java.lang.reflect.Method> findMethod​(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.String parameterTypeNames)  
      private static java.util.Optional<java.lang.reflect.Method> findMethod​(java.lang.Class<?> clazz, java.util.function.Predicate<java.lang.reflect.Method> predicate)  
      static java.util.List<java.lang.reflect.Method> findMethods​(java.lang.Class<?> clazz, java.util.function.Predicate<java.lang.reflect.Method> predicate)
      Find all methods of the supplied class or interface that match the specified predicate, using top-down search semantics within the type hierarchy.
      static java.util.List<java.lang.reflect.Method> findMethods​(java.lang.Class<?> clazz, java.util.function.Predicate<java.lang.reflect.Method> predicate, ReflectionUtils.HierarchyTraversalMode traversalMode)  
      static java.util.List<java.lang.Class<?>> findNestedClasses​(java.lang.Class<?> clazz, java.util.function.Predicate<java.lang.Class<?>> predicate)  
      private static void findNestedClasses​(java.lang.Class<?> clazz, java.util.function.Predicate<java.lang.Class<?>> predicate, java.util.Set<java.lang.Class<?>> candidates)  
      static java.util.Set<java.lang.Class<?>> getAllAssignmentCompatibleClasses​(java.lang.Class<?> clazz)
      Return all classes and interfaces that can be used as assignment types for instances of the specified Class, including itself.
      private static void getAllAssignmentCompatibleClasses​(java.lang.Class<?> clazz, java.util.Set<java.lang.Class<?>> result)  
      static java.util.Set<java.nio.file.Path> getAllClasspathRootDirectories()  
      static <T> java.lang.reflect.Constructor<T> getDeclaredConstructor​(java.lang.Class<T> clazz)
      Get the sole declared, non-synthetic Constructor for the supplied class.
      private static java.util.List<java.lang.reflect.Field> getDeclaredFields​(java.lang.Class<?> clazz)
      Custom alternative to Class.getDeclaredFields() that sorts the fields and converts them to a mutable list.
      private static java.util.List<java.lang.reflect.Method> getDeclaredMethods​(java.lang.Class<?> clazz, ReflectionUtils.HierarchyTraversalMode traversalMode)
      Custom alternative to Class.getDeclaredMethods() that sorts the methods and converts them to a mutable list.
      private static java.util.List<java.lang.reflect.Method> getDefaultMethods​(java.lang.Class<?> clazz)
      Get a sorted, mutable list of all default methods present in interfaces implemented by the supplied class which are also visible within the supplied class.
      private static java.util.List<java.lang.reflect.Field> getFields​(java.lang.Class<?> clazz)
      Custom alternative to Class.getFields() that sorts the fields and converts them to a mutable list.
      static java.lang.String getFullyQualifiedMethodName​(java.lang.Class<?> clazz, java.lang.reflect.Method method)
      Build the fully qualified method name for the method described by the supplied class and method.
      static java.lang.String getFullyQualifiedMethodName​(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.Class<?>... parameterTypes)
      Build the fully qualified method name for the method described by the supplied class, method name, and parameter types.
      private static java.util.List<java.lang.reflect.Field> getInterfaceFields​(java.lang.Class<?> clazz, ReflectionUtils.HierarchyTraversalMode traversalMode)  
      private static java.util.List<java.lang.reflect.Method> getInterfaceMethods​(java.lang.Class<?> clazz, ReflectionUtils.HierarchyTraversalMode traversalMode)  
      (package private) static java.util.Optional<java.lang.reflect.Method> getMethod​(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.Class<?>... parameterTypes)
      Deprecated.
      Please use tryToGetMethod(Class, String, Class[]) instead.
      private static java.util.List<java.lang.reflect.Method> getMethods​(java.lang.Class<?> clazz)
      Custom alternative to Class.getMethods() that sorts the methods and converts them to a mutable list.
      private static java.util.Optional<java.lang.Object> getOuterInstance​(java.lang.Object inner)  
      static java.util.Optional<java.lang.Object> getOutermostInstance​(java.lang.Object inner, java.lang.Class<?> requiredType)
      Deprecated.
      Please discontinue use of this method since it relies on internal implementation details of the JDK that may not work in the future.
      static java.lang.reflect.Method getRequiredMethod​(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.Class<?>... parameterTypes)
      Find the first Method of the supplied class or interface that meets the specified criteria, beginning with the specified class or interface and traversing up the type hierarchy until such a method is found or the type hierarchy is exhausted.
      private static java.util.List<java.lang.reflect.Field> getSuperclassFields​(java.lang.Class<?> clazz, ReflectionUtils.HierarchyTraversalMode traversalMode)  
      private static java.util.List<java.lang.reflect.Method> getSuperclassMethods​(java.lang.Class<?> clazz, ReflectionUtils.HierarchyTraversalMode traversalMode)  
      private static java.lang.Throwable getUnderlyingCause​(java.lang.Throwable t)
      Get the underlying cause of the supplied Throwable.
      static java.lang.Class<?> getWrapperType​(java.lang.Class<?> type)
      Get the wrapper type for the supplied primitive type.
      private static boolean hasCompatibleSignature​(java.lang.reflect.Method candidate, java.lang.String methodName, java.lang.Class<?>[] parameterTypes)
      Determine if the supplied candidate method (typically a method higher in the type hierarchy) has a signature that is compatible with a method that has the supplied name and parameter types, taking method sub-signatures and generics into account.
      static java.lang.Object invokeMethod​(java.lang.reflect.Method method, java.lang.Object target, java.lang.Object... args)  
      static boolean isAbstract​(java.lang.Class<?> clazz)  
      static boolean isAbstract​(java.lang.reflect.Member member)  
      static boolean isArray​(java.lang.Object obj)
      Determine if the supplied object is an array.
      static boolean isAssignableTo​(java.lang.Object obj, java.lang.Class<?> targetType)
      Determine if the supplied object can be assigned to the supplied target type for the purpose of reflective method invocations.
      private static boolean isFieldShadowedByLocalFields​(java.lang.reflect.Field field, java.util.List<java.lang.reflect.Field> localFields)  
      static boolean isFinal​(java.lang.Class<?> clazz)  
      static boolean isFinal​(java.lang.reflect.Member member)  
      (package private) static boolean isGeneric​(java.lang.reflect.Method method)  
      private static boolean isGeneric​(java.lang.reflect.Type type)  
      static boolean isInnerClass​(java.lang.Class<?> clazz)
      Determine if the supplied class is an inner class (i.e., a non-static member class).
      static boolean isMethodPresent​(java.lang.Class<?> clazz, java.util.function.Predicate<java.lang.reflect.Method> predicate)
      Determine if a Method matching the supplied Predicate is present within the type hierarchy of the specified class, beginning with the specified class or interface and traversing up the type hierarchy until such a method is found or the type hierarchy is exhausted.
      private static boolean isMethodShadowedBy​(java.lang.reflect.Method upper, java.lang.reflect.Method lower)  
      private static boolean isMethodShadowedByLocalMethods​(java.lang.reflect.Method method, java.util.List<java.lang.reflect.Method> localMethods)  
      static boolean isMultidimensionalArray​(java.lang.Object obj)
      Determine if the supplied object is a multidimensional array.
      static boolean isNotFinal​(java.lang.Class<?> clazz)  
      static boolean isNotFinal​(java.lang.reflect.Member member)  
      static boolean isNotPrivate​(java.lang.Class<?> clazz)  
      static boolean isNotPrivate​(java.lang.reflect.Member member)  
      static boolean isNotStatic​(java.lang.Class<?> clazz)  
      static boolean isNotStatic​(java.lang.reflect.Member member)  
      static boolean isPrivate​(java.lang.Class<?> clazz)  
      static boolean isPrivate​(java.lang.reflect.Member member)  
      static boolean isPublic​(java.lang.Class<?> clazz)  
      static boolean isPublic​(java.lang.reflect.Member member)  
      private static boolean isSearchable​(java.lang.Class<?> clazz)
      Determine if the supplied class is searchable: is non-null and is not equal to the class reference for java.lang.Object.
      static boolean isStatic​(java.lang.Class<?> clazz)  
      static boolean isStatic​(java.lang.reflect.Member member)  
      (package private) static boolean isWideningConversion​(java.lang.Class<?> sourceType, java.lang.Class<?> targetType)
      Determine if Java supports a widening primitive conversion from the supplied source type to the supplied primitive target type.
      private static java.lang.Class<?> loadArrayType​(java.lang.ClassLoader classLoader, java.lang.String componentTypeName, int dimensions)  
      static java.util.Optional<java.lang.Class<?>> loadClass​(java.lang.String name)
      Deprecated.
      Please use tryToLoadClass(String) instead.
      static java.util.Optional<java.lang.Class<?>> loadClass​(java.lang.String name, java.lang.ClassLoader classLoader)
      Deprecated.
      Please use tryToLoadClass(String, ClassLoader) instead.
      private static java.lang.Class<?> loadRequiredParameterType​(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.String typeName)  
      static <T extends java.lang.reflect.AccessibleObject>
      T      		 makeAccessible​(T object)  
      static <T> T newInstance​(java.lang.Class<T> clazz, java.lang.Object... args)  
      static <T> T newInstance​(java.lang.reflect.Constructor<T> constructor, java.lang.Object... args)
      Create a new instance of type T by invoking the supplied constructor with the supplied arguments.
      static java.lang.String[] parseFullyQualifiedMethodName​(java.lang.String fullyQualifiedMethodName)
      Parse the supplied fully qualified method name into a 3-element String[] with the following content.
      static <T> java.util.Optional<java.lang.Object> readFieldValue​(java.lang.Class<T> clazz, java.lang.String fieldName, T instance)
      Deprecated.
      Please use tryToReadFieldValue(Class, String, Object) instead.
      static java.util.Optional<java.lang.Object> readFieldValue​(java.lang.reflect.Field field)
      Deprecated.
      Please use tryToReadFieldValue(Field) instead.
      static java.util.Optional<java.lang.Object> readFieldValue​(java.lang.reflect.Field field, java.lang.Object instance)
      Deprecated.
      Please use tryToReadFieldValue(Field, Object) instead.
      static java.util.List<java.lang.Object> readFieldValues​(java.util.List<java.lang.reflect.Field> fields, java.lang.Object instance)
      Read the values of the supplied fields, making each field accessible if necessary and masking any checked exception as an unchecked exception.
      static java.util.List<java.lang.Object> readFieldValues​(java.util.List<java.lang.reflect.Field> fields, java.lang.Object instance, java.util.function.Predicate<java.lang.reflect.Field> predicate)
      Read the values of the supplied fields, making each field accessible if necessary, masking any checked exception as an unchecked exception, and filtering out fields that do not pass the supplied predicate.
      private static java.lang.Class<?>[] resolveParameterTypes​(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.String parameterTypeNames)  
      static boolean returnsVoid​(java.lang.reflect.Method method)  
      private static java.util.List<java.lang.reflect.Field> toSortedMutableList​(java.lang.reflect.Field[] fields)  
      private static java.util.List<java.lang.reflect.Method> toSortedMutableList​(java.lang.reflect.Method[] methods)  
      static Try<java.lang.reflect.Method> tryToGetMethod​(java.lang.Class<?> clazz, java.lang.String methodName, java.lang.Class<?>... parameterTypes)
      Try to get the Method in the specified class with the specified name and parameter types.
      static Try<java.lang.Class<?>> tryToLoadClass​(java.lang.String name)  
      static Try<java.lang.Class<?>> tryToLoadClass​(java.lang.String name, java.lang.ClassLoader classLoader)
      Try to load a class by its primitive name or fully qualified name, using the supplied ClassLoader.
      static <T> Try<java.lang.Object> tryToReadFieldValue​(java.lang.Class<T> clazz, java.lang.String fieldName, T instance)
      Try to read the value of a potentially inaccessible or nonexistent field.
      static Try<java.lang.Object> tryToReadFieldValue​(java.lang.reflect.Field field)
      Try to read the value of a potentially inaccessible static field.
      static Try<java.lang.Object> tryToReadFieldValue​(java.lang.reflect.Field field, java.lang.Object instance)  

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • logger

        private static final Logger logger

      • VM_INTERNAL_OBJECT_ARRAY_PATTERN

        private static final java.util.regex.Pattern VM_INTERNAL_OBJECT_ARRAY_PATTERN

      • VM_INTERNAL_PRIMITIVE_ARRAY_PATTERN

        private static final java.util.regex.Pattern VM_INTERNAL_PRIMITIVE_ARRAY_PATTERN
        Pattern: "[x", "[[[[x", etc., where x is Z, B, C, D, F, I, J, S, etc.

        The pattern intentionally captures the last bracket with the capital letter so that the combination can be looked up via classNameToTypeMap. For example, the last matched group will contain "[I" instead of simply "I".

        See Also:
        Class.getName()

      • SOURCE_CODE_SYNTAX_ARRAY_PATTERN

        private static final java.util.regex.Pattern SOURCE_CODE_SYNTAX_ARRAY_PATTERN

      • EMPTY_CLASS_ARRAY

        private static final java.lang.Class<?>[] EMPTY_CLASS_ARRAY

      • noCyclesDetectedCache

        private static final java.util.Set<java.lang.String> noCyclesDetectedCache
        Set of fully qualified class names for which no cycles have been detected in inner class hierarchies.

        This serves as a cache to avoid repeated cycle detection for classes that have already been checked.

        Since:
        1.6
        See Also:
        detectInnerClassCycle(Class)

      • classNameToTypeMap

        private static final java.util.Map<java.lang.String,​java.lang.Class<?>> classNameToTypeMap
        Internal cache of common class names mapped to their types.

      • primitiveToWrapperMap

        private static final java.util.Map<java.lang.Class<?>,​java.lang.Class<?>> primitiveToWrapperMap
        Internal cache of primitive types mapped to their wrapper types.

    • Constructor Detail

      • ReflectionUtils

        private ReflectionUtils()

    • Method Detail

      • isPublic

        public static boolean isPublic​(java.lang.Class<?> clazz)

      • isPublic

        public static boolean isPublic​(java.lang.reflect.Member member)

      • isPrivate

        public static boolean isPrivate​(java.lang.Class<?> clazz)

      • isPrivate

        public static boolean isPrivate​(java.lang.reflect.Member member)

      • isNotPrivate

        @API(status=INTERNAL,
     since="1.4")
public static boolean isNotPrivate​(java.lang.Class<?> clazz)

      • isNotPrivate

        @API(status=INTERNAL,
     since="1.1")
public static boolean isNotPrivate​(java.lang.reflect.Member member)

      • isAbstract

        public static boolean isAbstract​(java.lang.Class<?> clazz)

      • isAbstract

        public static boolean isAbstract​(java.lang.reflect.Member member)

      • isStatic

        public static boolean isStatic​(java.lang.Class<?> clazz)

      • isNotStatic

        @API(status=INTERNAL,
     since="1.4")
public static boolean isNotStatic​(java.lang.Class<?> clazz)

      • isStatic

        public static boolean isStatic​(java.lang.reflect.Member member)

      • isNotStatic

        @API(status=INTERNAL,
     since="1.1")
public static boolean isNotStatic​(java.lang.reflect.Member member)

      • isFinal

        @API(status=INTERNAL,
     since="1.5")
public static boolean isFinal​(java.lang.Class<?> clazz)
        Since:
        1.5

      • isNotFinal

        @API(status=INTERNAL,
     since="1.5")
public static boolean isNotFinal​(java.lang.Class<?> clazz)
        Since:
        1.5

      • isFinal

        @API(status=INTERNAL,
     since="1.5")
public static boolean isFinal​(java.lang.reflect.Member member)
        Since:
        1.5

      • isNotFinal

        @API(status=INTERNAL,
     since="1.5")
public static boolean isNotFinal​(java.lang.reflect.Member member)
        Since:
        1.5

      • isInnerClass

        public static boolean isInnerClass​(java.lang.Class<?> clazz)
        Determine if the supplied class is an inner class (i.e., a non-static member class).

        Technically speaking (i.e., according to the Java Language Specification), "an inner class may be a non-static member class, a local class, or an anonymous class." However, this method does not return true for a local or anonymous class.

        Parameters:
        clazz - the class to check; never null
        Returns:
        true if the class is an inner class

      • returnsVoid

        public static boolean returnsVoid​(java.lang.reflect.Method method)

      • isArray

        public static boolean isArray​(java.lang.Object obj)
        Determine if the supplied object is an array.
        Parameters:
        obj - the object to test; potentially null
        Returns:
        true if the object is an array

      • isMultidimensionalArray

        @API(status=INTERNAL,
     since="1.3.2")
public static boolean isMultidimensionalArray​(java.lang.Object obj)
        Determine if the supplied object is a multidimensional array.
        Parameters:
        obj - the object to test; potentially null
        Returns:
        true if the object is a multidimensional array
        Since:
        1.3.2

      • isAssignableTo

        public static boolean isAssignableTo​(java.lang.Object obj,
                                     java.lang.Class<?> targetType)
        Determine if the supplied object can be assigned to the supplied target type for the purpose of reflective method invocations.

        In contrast to Class.isInstance(Object), this method returns true if the target type represents a primitive type whose wrapper matches the supplied object's type. In addition, this method also supports widening conversions for primitive types and their corresponding wrapper types.

        If the supplied object is null and the supplied type does not represent a primitive type, this method returns true.

        Parameters:
        obj - the object to test for assignment compatibility; potentially null
        targetType - the type to check against; never null
        Returns:
        true if the object is assignment compatible
        See Also:
        Class.isInstance(Object), Class.isAssignableFrom(Class)

      • isWideningConversion

        static boolean isWideningConversion​(java.lang.Class<?> sourceType,
                                    java.lang.Class<?> targetType)
        Determine if Java supports a widening primitive conversion from the supplied source type to the supplied primitive target type.

      • getWrapperType

        public static java.lang.Class<?> getWrapperType​(java.lang.Class<?> type)
        Get the wrapper type for the supplied primitive type.
        Parameters:
        type - the primitive type for which to retrieve the wrapper type
        Returns:
        the corresponding wrapper type or null if the supplied type is null or not a primitive type

      • newInstance

        public static <T> T newInstance​(java.lang.reflect.Constructor<T> constructor,
                                java.lang.Object... args)
        Create a new instance of type T by invoking the supplied constructor with the supplied arguments.

        The constructor will be made accessible if necessary, and any checked exception will be masked as an unchecked exception.

        Parameters:
        constructor - the constructor to invoke; never null
        args - the arguments to pass to the constructor
        Returns:
        the new instance; never null
        See Also:
        newInstance(Class, Object...), ExceptionUtils.throwAsUncheckedException(Throwable)

      • readFieldValue

        @API(status=DEPRECATED,
     since="1.4")
@Deprecated
public static <T> java.util.Optional<java.lang.Object> readFieldValue​(java.lang.Class<T> clazz,
                                                                      java.lang.String fieldName,
                                                                      T instance)
        Deprecated.
        Please use tryToReadFieldValue(Class, String, Object) instead.
        Read the value of a potentially inaccessible or nonexistent field.

        If the field does not exist or the value of the field is null, an empty Optional will be returned.

        Parameters:
        clazz - the class where the field is declared; never null
        fieldName - the name of the field; never null or empty
        instance - the instance from where the value is to be read; may be null for a static field
        See Also:
        readFieldValue(Field), readFieldValue(Field, Object)

      • tryToReadFieldValue

        @API(status=INTERNAL,
     since="1.4")
public static <T> Try<java.lang.Object> tryToReadFieldValue​(java.lang.Class<T> clazz,
                                                            java.lang.String fieldName,
                                                            T instance)
        Try to read the value of a potentially inaccessible or nonexistent field.

        If the field does not exist or an exception occurs while reading it, a failed Try is returned that contains the corresponding exception.

        Parameters:
        clazz - the class where the field is declared; never null
        fieldName - the name of the field; never null or empty
        instance - the instance from where the value is to be read; may be null for a static field
        Since:
        1.4
        See Also:
        tryToReadFieldValue(Field), tryToReadFieldValue(Field, Object)

      • readFieldValue

        @API(status=DEPRECATED,
     since="1.4")
@Deprecated
public static java.util.Optional<java.lang.Object> readFieldValue​(java.lang.reflect.Field field)
        Deprecated.
        Please use tryToReadFieldValue(Field) instead.
        Read the value of the supplied static field, making it accessible if necessary and masking any checked exception as an unchecked exception.

        If the value of the field is null, an empty Optional will be returned.

        Parameters:
        field - the field to read; never null
        See Also:
        readFieldValue(Field, Object), readFieldValue(Class, String, Object)

      • tryToReadFieldValue

        @API(status=INTERNAL,
     since="1.4")
public static Try<java.lang.Object> tryToReadFieldValue​(java.lang.reflect.Field field)
        Try to read the value of a potentially inaccessible static field.

        If an exception occurs while reading the field, a failed Try is returned that contains the corresponding exception.

        Parameters:
        field - the field to read; never null
        Since:
        1.4
        See Also:
        tryToReadFieldValue(Field, Object), tryToReadFieldValue(Class, String, Object)

      • readFieldValue

        @API(status=DEPRECATED,
     since="1.4")
@Deprecated
public static java.util.Optional<java.lang.Object> readFieldValue​(java.lang.reflect.Field field,
                                                                  java.lang.Object instance)
        Deprecated.
        Please use tryToReadFieldValue(Field, Object) instead.
        Read the value of the supplied field, making it accessible if necessary and masking any checked exception as an unchecked exception.

        If the value of the field is null, an empty Optional will be returned.

        Parameters:
        field - the field to read; never null
        instance - the instance from which the value is to be read; may be null for a static field
        See Also:
        readFieldValue(Field), readFieldValue(Class, String, Object)

      • readFieldValues

        public static java.util.List<java.lang.Object> readFieldValues​(java.util.List<java.lang.reflect.Field> fields,
                                                               java.lang.Object instance)
        Read the values of the supplied fields, making each field accessible if necessary and masking any checked exception as an unchecked exception.
        Parameters:
        fields - the list of fields to read; never null
        instance - the instance from which the values are to be read; may be null for static fields
        Returns:
        an immutable list of the values of the specified fields; never null but may be empty or contain null entries

      • readFieldValues

        public static java.util.List<java.lang.Object> readFieldValues​(java.util.List<java.lang.reflect.Field> fields,
                                                               java.lang.Object instance,
                                                               java.util.function.Predicate<java.lang.reflect.Field> predicate)
        Read the values of the supplied fields, making each field accessible if necessary, masking any checked exception as an unchecked exception, and filtering out fields that do not pass the supplied predicate.
        Parameters:
        fields - the list of fields to read; never null
        instance - the instance from which the values are to be read; may be null for static fields
        predicate - the field filter; never null
        Returns:
        an immutable list of the values of the specified fields; never null but may be empty or contain null entries

      • loadClass

        @API(status=DEPRECATED,
     since="1.4")
@Deprecated
public static java.util.Optional<java.lang.Class<?>> loadClass​(java.lang.String name,
                                                               java.lang.ClassLoader classLoader)
        Deprecated.
        Please use tryToLoadClass(String, ClassLoader) instead.
        Load a class by its primitive name or fully qualified name, using the supplied ClassLoader.

        See ReflectionSupport.loadClass(String) for details on support for class names for arrays.

        Parameters:
        name - the name of the class to load; never null or blank
        classLoader - the ClassLoader to use; never null
        See Also:
        loadClass(String)

      • tryToLoadClass

        @API(status=INTERNAL,
     since="1.4")
public static Try<java.lang.Class<?>> tryToLoadClass​(java.lang.String name,
                                                     java.lang.ClassLoader classLoader)
        Try to load a class by its primitive name or fully qualified name, using the supplied ClassLoader.

        See ReflectionSupport.tryToLoadClass(String) for details on support for class names for arrays.

        Parameters:
        name - the name of the class to load; never null or blank
        classLoader - the ClassLoader to use; never null
        Since:
        1.4
        See Also:
        tryToLoadClass(String)

      • loadArrayType

        private static java.lang.Class<?> loadArrayType​(java.lang.ClassLoader classLoader,
                                                java.lang.String componentTypeName,
                                                int dimensions)
                                         throws java.lang.ClassNotFoundException
        Throws:
        java.lang.ClassNotFoundException

      • getFullyQualifiedMethodName

        public static java.lang.String getFullyQualifiedMethodName​(java.lang.Class<?> clazz,
                                                           java.lang.reflect.Method method)
        Build the fully qualified method name for the method described by the supplied class and method.

        Note that the class is not necessarily the class in which the method is declared.

        Parameters:
        clazz - the class from which the method should be referenced; never null
        method - the method; never null
        Returns:
        fully qualified method name; never null
        Since:
        1.4
        See Also:
        getFullyQualifiedMethodName(Class, String, Class...)

      • getFullyQualifiedMethodName

        public static java.lang.String getFullyQualifiedMethodName​(java.lang.Class<?> clazz,
                                                           java.lang.String methodName,
                                                           java.lang.Class<?>... parameterTypes)
        Build the fully qualified method name for the method described by the supplied class, method name, and parameter types.

        Note that the class is not necessarily the class in which the method is declared.

        Parameters:
        clazz - the class from which the method should be referenced; never null
        methodName - the name of the method; never null or blank
        parameterTypes - the parameter types of the method; may be null or empty
        Returns:
        fully qualified method name; never null
        See Also:
        getFullyQualifiedMethodName(Class, Method)

      • parseFullyQualifiedMethodName

        public static java.lang.String[] parseFullyQualifiedMethodName​(java.lang.String fullyQualifiedMethodName)
        Parse the supplied fully qualified method name into a 3-element String[] with the following content.
        • index 0: the fully qualified class name
        • index 1: the name of the method
        • index 2: a comma-separated list of parameter types, or a blank string if the method does not declare any formal parameters
        Parameters:
        fullyQualifiedMethodName - a fully qualified method name, never null or blank
        Returns:
        a 3-element array of strings containing the parsed values

      • getOutermostInstance

        @API(status=DEPRECATED,
     since="1.4")
@Deprecated
public static java.util.Optional<java.lang.Object> getOutermostInstance​(java.lang.Object inner,
                                                                        java.lang.Class<?> requiredType)
        Deprecated.
        Please discontinue use of this method since it relies on internal implementation details of the JDK that may not work in the future.
        Get the outermost instance of the required type, searching recursively through enclosing instances.

        If the supplied inner object is of the required type, it will simply be returned.

        Parameters:
        inner - the inner object from which to begin the search; never null
        requiredType - the required type of the outermost instance; never null
        Returns:
        an Optional containing the outermost instance; never null but potentially empty

      • getOuterInstance

        private static java.util.Optional<java.lang.Object> getOuterInstance​(java.lang.Object inner)

      • getAllClasspathRootDirectories

        public static java.util.Set<java.nio.file.Path> getAllClasspathRootDirectories()

      • findAllClassesInClasspathRoot

        public static java.util.List<java.lang.Class<?>> findAllClassesInClasspathRoot​(java.net.URI root,
                                                                               ClassFilter classFilter)
        Since:
        1.1

      • findAllClassesInPackage

        public static java.util.List<java.lang.Class<?>> findAllClassesInPackage​(java.lang.String basePackageName,
                                                                         ClassFilter classFilter)
        Since:
        1.1

      • findAllClassesInModule

        public static java.util.List<java.lang.Class<?>> findAllClassesInModule​(java.lang.String moduleName,
                                                                        java.util.function.Predicate<java.lang.Class<?>> classFilter,
                                                                        java.util.function.Predicate<java.lang.String> classNameFilter)
        Since:
        1.1.1
        See Also:
        ReflectionSupport.findAllClassesInModule(String, Predicate, Predicate)

      • findAllClassesInModule

        public static java.util.List<java.lang.Class<?>> findAllClassesInModule​(java.lang.String moduleName,
                                                                        ClassFilter classFilter)
        Since:
        1.1.1

      • findNestedClasses

        private static void findNestedClasses​(java.lang.Class<?> clazz,
                                      java.util.function.Predicate<java.lang.Class<?>> predicate,
                                      java.util.Set<java.lang.Class<?>> candidates)

      • detectInnerClassCycle

        private static void detectInnerClassCycle​(java.lang.Class<?> clazz)
        Detect a cycle in the inner class hierarchy in which the supplied class resides — from the supplied class up to the outermost enclosing class — and throw a JUnitException if a cycle is detected.

        This method does not detect cycles within inner class hierarchies below the supplied class.

        If the supplied class is not an inner class and does not have a searchable superclass, this method is effectively a no-op.

        Since:
        1.6
        See Also:
        isInnerClass(Class), isSearchable(Class)

      • getDeclaredConstructor

        public static <T> java.lang.reflect.Constructor<T> getDeclaredConstructor​(java.lang.Class<T> clazz)
        Get the sole declared, non-synthetic Constructor for the supplied class.

        Throws a PreconditionViolationException if the supplied class declares more than one non-synthetic constructor.

        Parameters:
        clazz - the class to get the constructor for
        Returns:
        the sole declared constructor; never null
        See Also:
        Class.getDeclaredConstructors(), Class.isSynthetic()

      • findConstructors

        public static java.util.List<java.lang.reflect.Constructor<?>> findConstructors​(java.lang.Class<?> clazz,
                                                                                java.util.function.Predicate<java.lang.reflect.Constructor<?>> predicate)
        Find all constructors in the supplied class that match the supplied predicate.

        Note that this method may return synthetic constructors. If you wish to ignore synthetic constructors, you may filter them out with the supplied predicate or filter them out of the list returned by this method.

        Parameters:
        clazz - the class in which to search for constructors; never null
        predicate - the predicate to use to test for a match; never null
        Returns:
        an immutable list of all such constructors found; never null but potentially empty
        See Also:
        Class.getDeclaredConstructors(), Class.isSynthetic()

      • findAllFieldsInHierarchy

        private static java.util.List<java.lang.reflect.Field> findAllFieldsInHierarchy​(java.lang.Class<?> clazz,
                                                                                ReflectionUtils.HierarchyTraversalMode traversalMode)

      • isMethodPresent

        public static boolean isMethodPresent​(java.lang.Class<?> clazz,
                                      java.util.function.Predicate<java.lang.reflect.Method> predicate)
        Determine if a Method matching the supplied Predicate is present within the type hierarchy of the specified class, beginning with the specified class or interface and traversing up the type hierarchy until such a method is found or the type hierarchy is exhausted.
        Parameters:
        clazz - the class or interface in which to find the method; never null
        predicate - the predicate to use to test for a match; never null
        Returns:
        true if such a method is present
        See Also:
        findMethod(Class, String, String), findMethod(Class, String, Class...)

      • getMethod

        @API(status=DEPRECATED,
     since="1.4")
@Deprecated
static java.util.Optional<java.lang.reflect.Method> getMethod​(java.lang.Class<?> clazz,
                                                              java.lang.String methodName,
                                                              java.lang.Class<?>... parameterTypes)
        Deprecated.
        Please use tryToGetMethod(Class, String, Class[]) instead.
        Get the Method in the specified class with the specified name and parameter types.

        This method delegates to Class.getMethod(String, Class...) but swallows any exception thrown.

        Parameters:
        clazz - the class in which to search for the method; never null
        methodName - the name of the method to get; never null or blank
        parameterTypes - the parameter types of the method; may be null or empty
        Returns:
        an Optional containing the method; never null but empty if the invocation of Class#getMethod() throws a NoSuchMethodException

      • tryToGetMethod

        @API(status=INTERNAL,
     since="1.4")
public static Try<java.lang.reflect.Method> tryToGetMethod​(java.lang.Class<?> clazz,
                                                           java.lang.String methodName,
                                                           java.lang.Class<?>... parameterTypes)
        Try to get the Method in the specified class with the specified name and parameter types.

        This method delegates to Class.getMethod(String, Class...) but catches any exception thrown.

        Parameters:
        clazz - the class in which to search for the method; never null
        methodName - the name of the method to get; never null or blank
        parameterTypes - the parameter types of the method; may be null or empty
        Returns:
        a successful Try containing the method or a failed Try containing the NoSuchMethodException thrown by Class#getMethod(); never null
        Since:
        1.4

      • resolveParameterTypes

        private static java.lang.Class<?>[] resolveParameterTypes​(java.lang.Class<?> clazz,
                                                          java.lang.String methodName,
                                                          java.lang.String parameterTypeNames)

      • loadRequiredParameterType

        private static java.lang.Class<?> loadRequiredParameterType​(java.lang.Class<?> clazz,
                                                            java.lang.String methodName,
                                                            java.lang.String typeName)

      • findMethod

        private static java.util.Optional<java.lang.reflect.Method> findMethod​(java.lang.Class<?> clazz,
                                                                       java.util.function.Predicate<java.lang.reflect.Method> predicate)

      • getRequiredMethod

        @API(status=STABLE,
     since="1.7")
public static java.lang.reflect.Method getRequiredMethod​(java.lang.Class<?> clazz,
                                                         java.lang.String methodName,
                                                         java.lang.Class<?>... parameterTypes)
        Find the first Method of the supplied class or interface that meets the specified criteria, beginning with the specified class or interface and traversing up the type hierarchy until such a method is found or the type hierarchy is exhausted.

        Use this method as an alternative to findMethod(Class, String, Class...) for use cases in which the method is required to be present.

        Parameters:
        clazz - the class or interface in which to find the method; never null
        methodName - the name of the method to find; never null or empty
        parameterTypes - the types of parameters accepted by the method, if any; never null
        Returns:
        the Method found; never null
        Throws:
        JUnitException - if no method is found
        Since:
        1.7
        See Also:
        findMethod(Class, String, Class...)

      • findMethods

        public static java.util.List<java.lang.reflect.Method> findMethods​(java.lang.Class<?> clazz,
                                                                   java.util.function.Predicate<java.lang.reflect.Method> predicate)
        Find all methods of the supplied class or interface that match the specified predicate, using top-down search semantics within the type hierarchy.

        The results will not contain instance methods that are overridden or static methods that are hidden.

        Parameters:
        clazz - the class or interface in which to find the methods; never null
        predicate - the method filter; never null
        Returns:
        an immutable list of all such methods found; never null
        See Also:
        ReflectionUtils.HierarchyTraversalMode.TOP_DOWN, findMethods(Class, Predicate, HierarchyTraversalMode)

      • findAllMethodsInHierarchy

        private static java.util.List<java.lang.reflect.Method> findAllMethodsInHierarchy​(java.lang.Class<?> clazz,
                                                                                  ReflectionUtils.HierarchyTraversalMode traversalMode)
        Find all non-synthetic methods in the superclass and interface hierarchy, excluding Object.

      • getFields

        private static java.util.List<java.lang.reflect.Field> getFields​(java.lang.Class<?> clazz)
        Custom alternative to Class.getFields() that sorts the fields and converts them to a mutable list.

      • getDeclaredFields

        private static java.util.List<java.lang.reflect.Field> getDeclaredFields​(java.lang.Class<?> clazz)
        Custom alternative to Class.getDeclaredFields() that sorts the fields and converts them to a mutable list.

      • getMethods

        private static java.util.List<java.lang.reflect.Method> getMethods​(java.lang.Class<?> clazz)
        Custom alternative to Class.getMethods() that sorts the methods and converts them to a mutable list.

      • getDeclaredMethods

        private static java.util.List<java.lang.reflect.Method> getDeclaredMethods​(java.lang.Class<?> clazz,
                                                                           ReflectionUtils.HierarchyTraversalMode traversalMode)
        Custom alternative to Class.getDeclaredMethods() that sorts the methods and converts them to a mutable list.

        In addition, the list returned by this method includes interface default methods which are either prepended or appended to the list of declared methods depending on the supplied traversal mode.

      • getDefaultMethods

        private static java.util.List<java.lang.reflect.Method> getDefaultMethods​(java.lang.Class<?> clazz)
        Get a sorted, mutable list of all default methods present in interfaces implemented by the supplied class which are also visible within the supplied class.
        See Also:
        Method Visibility in the Java Language Specification

      • toSortedMutableList

        private static java.util.List<java.lang.reflect.Field> toSortedMutableList​(java.lang.reflect.Field[] fields)

      • toSortedMutableList

        private static java.util.List<java.lang.reflect.Method> toSortedMutableList​(java.lang.reflect.Method[] methods)

      • defaultFieldSorter

        private static int defaultFieldSorter​(java.lang.reflect.Field field1,
                                      java.lang.reflect.Field field2)
        Field comparator inspired by JUnit 4's org.junit.internal.MethodSorter implementation.

      • defaultMethodSorter

        private static int defaultMethodSorter​(java.lang.reflect.Method method1,
                                       java.lang.reflect.Method method2)
        Method comparator based upon JUnit 4's org.junit.internal.MethodSorter implementation.

      • isFieldShadowedByLocalFields

        private static boolean isFieldShadowedByLocalFields​(java.lang.reflect.Field field,
                                                    java.util.List<java.lang.reflect.Field> localFields)

      • isMethodShadowedByLocalMethods

        private static boolean isMethodShadowedByLocalMethods​(java.lang.reflect.Method method,
                                                      java.util.List<java.lang.reflect.Method> localMethods)

      • isMethodShadowedBy

        private static boolean isMethodShadowedBy​(java.lang.reflect.Method upper,
                                          java.lang.reflect.Method lower)

      • hasCompatibleSignature

        private static boolean hasCompatibleSignature​(java.lang.reflect.Method candidate,
                                              java.lang.String methodName,
                                              java.lang.Class<?>[] parameterTypes)
        Determine if the supplied candidate method (typically a method higher in the type hierarchy) has a signature that is compatible with a method that has the supplied name and parameter types, taking method sub-signatures and generics into account.

      • isGeneric

        static boolean isGeneric​(java.lang.reflect.Method method)

      • isGeneric

        private static boolean isGeneric​(java.lang.reflect.Type type)

      • makeAccessible

        public static <T extends java.lang.reflect.AccessibleObject> T makeAccessible​(T object)

      • getAllAssignmentCompatibleClasses

        public static java.util.Set<java.lang.Class<?>> getAllAssignmentCompatibleClasses​(java.lang.Class<?> clazz)
        Return all classes and interfaces that can be used as assignment types for instances of the specified Class, including itself.
        Parameters:
        clazz - the Class to look up
        See Also:
        Class.isAssignableFrom(java.lang.Class<?>)

      • getAllAssignmentCompatibleClasses

        private static void getAllAssignmentCompatibleClasses​(java.lang.Class<?> clazz,
                                                      java.util.Set<java.lang.Class<?>> result)

      • isSearchable

        private static boolean isSearchable​(java.lang.Class<?> clazz)
        Determine if the supplied class is searchable: is non-null and is not equal to the class reference for java.lang.Object.

        This method is often used to determine if a superclass should be searched but may be applicable for other use cases as well.

        Since:
        1.6

      • getUnderlyingCause

        private static java.lang.Throwable getUnderlyingCause​(java.lang.Throwable t)
        Get the underlying cause of the supplied Throwable.

        If the supplied Throwable is an instance of InvocationTargetException, this method will be invoked recursively with the underlying target exception; otherwise, this method simply returns the supplied Throwable.