Class ReflectionUtils


  • public final class ReflectionUtils
    extends Object
    Created by Vahid Zafari on 8/12/2016.
    • Field Detail

      • USER_DECLARED_METHODS

        public static final ReflectionUtils.MethodFilter USER_DECLARED_METHODS
        Pre-built MethodFilter that matches all non-bridge non-synthetic methods which are not declared on java.lang.Object.
      • COPYABLE_FIELDS

        public static final ReflectionUtils.FieldFilter COPYABLE_FIELDS
        Pre-built FieldFilter that matches all non-static, non-final fields.
    • Method Detail

      • newInstance

        public static <T> T newInstance​(Class<T> clazz)
      • getGenericArgType

        public static <T> Class<T> getGenericArgType​(Class<?> clazz,
                                                     int genericArgIndex)
      • findField

        public static Field findField​(Class<?> type,
                                      ReflectionUtils.FieldFilter filter)
        Finds the first field on the given class matching the given ReflectionUtils.FieldFilter.
        Parameters:
        type - must not be null.
        filter - must not be null.
        Returns:
        the field matching the filter or null in case no field could be found.
      • findRequiredField

        public static Field findRequiredField​(Class<?> type,
                                              String name)
        Finds the field of the given name on the given type.
        Parameters:
        type - must not be null.
        name - must not be null or empty.
        Throws:
        IllegalArgumentException - in case the field can't be found.
      • findRequiredMethod

        public static Method findRequiredMethod​(Class<?> type,
                                                String name,
                                                Class<?>... parameterTypes)
        Returns the method with the given name of the given class and parameter types.
        Parameters:
        type - must not be null.
        name - must not be null.
        parameterTypes - must not be null.
        Throws:
        IllegalArgumentException - in case the method cannot be resolved.
      • returnTypeAndParameters

        public static Stream<Class<?>> returnTypeAndParameters​(Method method)
        Returns a Stream of the return and parameters types of the given Method.
        Parameters:
        method - must not be null.
      • getPrimitiveDefault

        public static Object getPrimitiveDefault​(Class<?> type)
        Get default value for a primitive type.
        Parameters:
        type - must not be null.
        Returns:
        boxed primitive default value.
      • getField

        public static Field getField​(Class<?> clazz,
                                     String fieldPath)
      • getContainerCLassByField

        public static Class<?> getContainerCLassByField​(Class<?> clazz,
                                                        String fieldPath)
      • getGetterName

        public static String getGetterName​(String property,
                                           Class<?> type)
        Parameters:
        property - , Class type
        Returns:
        getter of the given property, if the given property has boolean type add is to its first else add get
      • getSetterName

        public static String getSetterName​(String property)
      • getFieldAnnotationMap

        public static <T extends AnnotationMap<Field,​T> getFieldAnnotationMap​(Class<?> clazz,
                                                                                      Class<T> annotationClazz,
                                                                                      boolean includeSuperClasses)
      • getFields

        public static <T extends AnnotationList<Field> getFields​(Class<?> clazz,
                                                                   Class<T> annotationClazz,
                                                                   boolean includeSuperClasses)
      • isContainField

        public static boolean isContainField​(Set<String> fields,
                                             String fieldName)
      • methodToFieldName

        public static String methodToFieldName​(Method method)
      • lowerCaseFirstLetter

        public static String lowerCaseFirstLetter​(String name)
      • handleReflectionException

        public static void handleReflectionException​(Exception ex)
        Handle the given reflection exception.

        Should only be called if no checked exception is expected to be thrown by a target method, or if an error occurs while accessing a method or field.

        Throws the underlying RuntimeException or Error in case of an InvocationTargetException with such a root cause. Throws an IllegalStateException with an appropriate message or UndeclaredThrowableException otherwise.

        Parameters:
        ex - the reflection exception to handle
      • handleInvocationTargetException

        public static void handleInvocationTargetException​(InvocationTargetException ex)
        Handle the given invocation target exception. Should only be called if no checked exception is expected to be thrown by the target method.

        Throws the underlying RuntimeException or Error in case of such a root cause. Throws an UndeclaredThrowableException otherwise.

        Parameters:
        ex - the invocation target exception to handle
      • rethrowException

        public static void rethrowException​(Throwable ex)
                                     throws Exception
        Rethrow the given exception, which is presumably the target exception of an InvocationTargetException. Should only be called if no checked exception is expected to be thrown by the target method.

        Rethrows the underlying exception cast to an Exception or Error if appropriate; otherwise, throws an UndeclaredThrowableException.

        Parameters:
        ex - the exception to rethrow
        Throws:
        Exception - the rethrown exception (in case of a checked exception)
      • accessibleConstructor

        public static <T> Constructor<T> accessibleConstructor​(Class<T> clazz,
                                                               Class<?>... parameterTypes)
                                                        throws NoSuchMethodException
        Obtain an accessible constructor for the given class and parameters.
        Parameters:
        clazz - the clazz to check
        parameterTypes - the parameter types of the desired constructor
        Returns:
        the constructor reference
        Throws:
        NoSuchMethodException - if no such constructor exists
      • makeAccessible

        public static void makeAccessible​(Constructor<?> ctor)
        Make the given constructor accessible, explicitly setting it accessible if necessary. The setAccessible(true) method is only called when actually necessary, to avoid unnecessary conflicts with a JVM SecurityManager (if active).
        Parameters:
        ctor - the constructor to make accessible
      • findMethod

        public static Method findMethod​(Class<?> clazz,
                                        String name)
        Attempt to find a Method on the supplied class with the supplied name and no parameters. Searches all superclasses up to Object.

        Returns null if no Method can be found.

        Parameters:
        clazz - the class to introspect
        name - the name of the method
        Returns:
        the Method object, or null if none found
      • findMethod

        public static Method findMethod​(Class<?> clazz,
                                        String name,
                                        Class<?>... paramTypes)
        Attempt to find a Method on the supplied class with the supplied name and parameter types. Searches all superclasses up to Object.

        Returns null if no Method can be found.

        Parameters:
        clazz - the class to introspect
        name - the name of the method
        paramTypes - the parameter types of the method (may be null to indicate any signature)
        Returns:
        the Method object, or null if none found
      • invokeMethod

        public static Object invokeMethod​(Method method,
                                          Object target)
        Invoke the specified Method against the supplied target object with no arguments. The target object can be null when invoking a static Method.

        Thrown exceptions are handled via a call to handleReflectionException(java.lang.Exception).

        Parameters:
        method - the method to invoke
        target - the target object to invoke the method on
        Returns:
        the invocation result, if any
      • invokeMethod

        public static Object invokeMethod​(Method method,
                                          Object target,
                                          Object... args)
        Invoke the specified Method against the supplied target object with the supplied arguments. The target object can be null when invoking a static Method.

        Thrown exceptions are handled via a call to handleReflectionException(java.lang.Exception).

        Parameters:
        method - the method to invoke
        target - the target object to invoke the method on
        args - the invocation arguments (may be null)
        Returns:
        the invocation result, if any
      • declaresException

        public static boolean declaresException​(Method method,
                                                Class<?> exceptionType)
        Determine whether the given method explicitly declares the given exception or one of its superclasses, which means that an exception of that type can be propagated as-is within a reflective invocation.
        Parameters:
        method - the declaring method
        exceptionType - the exception to throw
        Returns:
        true if the exception can be thrown as-is; false if it needs to be wrapped
      • doWithLocalMethods

        public static void doWithLocalMethods​(Class<?> clazz,
                                              ReflectionUtils.MethodCallback mc)
        Perform the given callback operation on all matching methods of the given class, as locally declared or equivalent thereof (such as default methods on Java 8 based interfaces that the given class implements).
        Parameters:
        clazz - the class to introspect
        mc - the callback to invoke for each method
        Throws:
        IllegalStateException - if introspection fails
      • doWithMethods

        public static void doWithMethods​(Class<?> clazz,
                                         ReflectionUtils.MethodCallback mc)
        Perform the given callback operation on all matching methods of the given class and superclasses.

        The same named method occurring on subclass and superclass will appear twice, unless excluded by a ReflectionUtils.MethodFilter.

        Parameters:
        clazz - the class to introspect
        mc - the callback to invoke for each method
        Throws:
        IllegalStateException - if introspection fails
      • doWithMethods

        public static void doWithMethods​(Class<?> clazz,
                                         ReflectionUtils.MethodCallback mc,
                                         ReflectionUtils.MethodFilter mf)
        Perform the given callback operation on all matching methods of the given class and superclasses (or given interface and super-interfaces).

        The same named method occurring on subclass and superclass will appear twice, unless excluded by the specified ReflectionUtils.MethodFilter.

        Parameters:
        clazz - the class to introspect
        mc - the callback to invoke for each method
        mf - the filter that determines the methods to apply the callback to
        Throws:
        IllegalStateException - if introspection fails
      • getAllDeclaredMethods

        public static Method[] getAllDeclaredMethods​(Class<?> leafClass)
        Get all declared methods on the leaf class and all superclasses. Leaf class methods are included first.
        Parameters:
        leafClass - the class to introspect
        Throws:
        IllegalStateException - if introspection fails
      • getUniqueDeclaredMethods

        public static Method[] getUniqueDeclaredMethods​(Class<?> leafClass)
        Get the unique set of declared methods on the leaf class and all superclasses. Leaf class methods are included first and while traversing the superclass hierarchy any methods found with signatures matching a method already included are filtered out.
        Parameters:
        leafClass - the class to introspect
        Throws:
        IllegalStateException - if introspection fails
      • getUniqueDeclaredMethods

        public static Method[] getUniqueDeclaredMethods​(Class<?> leafClass,
                                                        ReflectionUtils.MethodFilter mf)
        Get the unique set of declared methods on the leaf class and all superclasses. Leaf class methods are included first and while traversing the superclass hierarchy any methods found with signatures matching a method already included are filtered out.
        Parameters:
        leafClass - the class to introspect
        mf - the filter that determines the methods to take into account
        Throws:
        IllegalStateException - if introspection fails
      • getDeclaredMethods

        public static Method[] getDeclaredMethods​(Class<?> clazz)
        Variant of Class.getDeclaredMethods() that uses a local cache in order to avoid the JVM's SecurityManager check and new Method instances. In addition, it also includes Java 8 default methods from locally implemented interfaces, since those are effectively to be treated just like declared methods.
        Parameters:
        clazz - the class to introspect
        Returns:
        the cached array of methods
        Throws:
        IllegalStateException - if introspection fails
      • isEqualsMethod

        public static boolean isEqualsMethod​(Method method)
        Determine whether the given method is an "equals" method.
      • isHashCodeMethod

        public static boolean isHashCodeMethod​(Method method)
        Determine whether the given method is a "hashCode" method.
      • isToStringMethod

        public static boolean isToStringMethod​(Method method)
        Determine whether the given method is a "toString" method.
      • isObjectMethod

        public static boolean isObjectMethod​(Method method)
        Determine whether the given method is originally declared by Object.
      • isCglibRenamedMethod

        public static boolean isCglibRenamedMethod​(Method renamedMethod)
        Determine whether the given method is a CGLIB 'renamed' method, following the pattern "CGLIB$methodName$0".
        Parameters:
        renamedMethod - the method to check
      • makeAccessible

        public static void makeAccessible​(Method method)
        Make the given method accessible, explicitly setting it accessible if necessary. The setAccessible(true) method is only called when actually necessary, to avoid unnecessary conflicts with a JVM SecurityManager (if active).
        Parameters:
        method - the method to make accessible
      • findField

        public static Field findField​(Class<?> clazz,
                                      String name)
        Attempt to find a field on the supplied Class with the supplied name. Searches all superclasses up to Object.
        Parameters:
        clazz - the class to introspect
        name - the name of the field
        Returns:
        the corresponding Field object, or null if not found
      • findField

        public static Field findField​(Class<?> clazz,
                                      String name,
                                      Class<?> type)
        Attempt to find a field on the supplied Class with the supplied name and/or type. Searches all superclasses up to Object.
        Parameters:
        clazz - the class to introspect
        name - the name of the field (may be null if type is specified)
        type - the type of the field (may be null if name is specified)
        Returns:
        the corresponding Field object, or null if not found
      • setField

        public static void setField​(Field field,
                                    Object target,
                                    Object value)
        Set the field represented by the supplied field object on the specified target object to the specified value.

        In accordance with Field.set(Object, Object) semantics, the new value is automatically unwrapped if the underlying field has a primitive type.

        This method does not support setting static final fields.

        Thrown exceptions are handled via a call to handleReflectionException(Exception).

        Parameters:
        field - the field to set
        target - the target object on which to set the field
        value - the value to set (may be null)
      • getField

        public static Object getField​(Field field,
                                      Object target)
        Get the field represented by the supplied field object on the specified target object. In accordance with Field.get(Object) semantics, the returned value is automatically wrapped if the underlying field has a primitive type.

        Thrown exceptions are handled via a call to handleReflectionException(Exception).

        Parameters:
        field - the field to get
        target - the target object from which to get the field
        Returns:
        the field's current value
      • doWithLocalFields

        public static void doWithLocalFields​(Class<?> clazz,
                                             ReflectionUtils.FieldCallback fc)
        Invoke the given callback on all locally declared fields in the given class.
        Parameters:
        clazz - the target class to analyze
        fc - the callback to invoke for each field
        Throws:
        IllegalStateException - if introspection fails
      • doWithFields

        public static void doWithFields​(Class<?> clazz,
                                        ReflectionUtils.FieldCallback fc)
        Invoke the given callback on all fields in the target class, going up the class hierarchy to get all declared fields.
        Parameters:
        clazz - the target class to analyze
        fc - the callback to invoke for each field
        Throws:
        IllegalStateException - if introspection fails
      • doWithFields

        public static void doWithFields​(Class<?> clazz,
                                        ReflectionUtils.FieldCallback fc,
                                        ReflectionUtils.FieldFilter ff)
        Invoke the given callback on all fields in the target class, going up the class hierarchy to get all declared fields.
        Parameters:
        clazz - the target class to analyze
        fc - the callback to invoke for each field
        ff - the filter that determines the fields to apply the callback to
        Throws:
        IllegalStateException - if introspection fails
      • shallowCopyFieldState

        public static void shallowCopyFieldState​(Object src,
                                                 Object dest)
        Given the source object and the destination, which must be the same class or a subclass, copy all fields, including inherited fields. Designed to work on objects with public no-arg constructors.
        Throws:
        IllegalStateException - if introspection fails
      • isPublicStaticFinal

        public static boolean isPublicStaticFinal​(Field field)
        Determine whether the given field is a "public static final" constant.
        Parameters:
        field - the field to check
      • makeAccessible

        public static void makeAccessible​(Field field)
        Make the given field accessible, explicitly setting it accessible if necessary. The setAccessible(true) method is only called when actually necessary, to avoid unnecessary conflicts with a JVM SecurityManager (if active).
        Parameters:
        field - the field to make accessible
      • getSubTypeOf

        public static <T> Set<Class<? extends T>> getSubTypeOf​(String packagePrefix,
                                                               Class<T> clazz)
      • getSupersOf

        public static List<Class<?>> getSupersOf​(Class<?> clazz,
                                                 boolean includeInterface,
                                                 boolean includeAbstractClasses,
                                                 boolean includeObjectClass)