Class GenericsUtils


  • public class GenericsUtils
    extends Object
    Utility methods to deal with generic types.
    • Constructor Detail

      • GenericsUtils

        public GenericsUtils()
    • Method Detail

      • alignGenericTypes

        @Deprecated
        public static GenericsType[] alignGenericTypes​(GenericsType[] redirectGenericTypes,
                                                       GenericsType[] parameterizedTypes,
                                                       GenericsType[] alignmentTarget)
        Deprecated.
        You shouldn't call this method because it is inherently unreliable
        Given a parameterized type and a generic type information, aligns actual type parameters. For example, if a class uses generic type
        <T,U,V>
        (redirectGenericTypes), is used with actual type parameters
        <java.lang.String, U,V>
        , then a class or interface using generic types
        <T,V>
        will be aligned to
        <java.lang.String,V>
        Parameters:
        redirectGenericTypes - the type arguments or the redirect class node
        parameterizedTypes - the actual type arguments used on this class node
        alignmentTarget - the generic type arguments to which we want to align to
        Returns:
        aligned type arguments
      • extractPlaceholders

        public static void extractPlaceholders​(ClassNode node,
                                               Map<GenericsType.GenericsTypeName,​GenericsType> map)
        For a given classnode, fills in the supplied map with the parameterized types it defines.
        Parameters:
        node - the class node to check
        map - the generics type information collector
      • toGenericTypesString

        public static String toGenericTypesString​(GenericsType[] genericsTypes)
      • parameterizeInterfaceGenerics

        @Deprecated
        public static ClassNode parameterizeInterfaceGenerics​(ClassNode hint,
                                                              ClassNode target)
        Deprecated.
        Use #parameterizeType instead
        Interface class nodes retrieved from ClassNode.getInterfaces() or ClassNode.getAllInterfaces() are returned with generic type arguments. This method allows returning a parameterized interface given the parameterized class node which implements this interface.
        Parameters:
        hint - the class node where generics types are parameterized
        target - the interface we want to parameterize generics types
        Returns:
        a parameterized interface class node
      • parameterizeType

        public static ClassNode parameterizeType​(ClassNode hint,
                                                 ClassNode target)
        Interface class nodes retrieved from ClassNode.getInterfaces() or ClassNode.getAllInterfaces() are returned with generic type arguments. This method allows returning a parameterized interface given the parameterized class node which implements this interface.
        Parameters:
        hint - the class node where generics types are parameterized
        target - the interface we want to parameterize generics types
        Returns:
        a parameterized interface class node
      • makeClassSafe

        public static ClassNode makeClassSafe​(Class klass)
      • makeClassSafeWithGenerics

        public static ClassNode makeClassSafeWithGenerics​(Class klass,
                                                          ClassNode genericsType)
      • applyGenericsContextToPlaceHolders

        public static GenericsType[] applyGenericsContextToPlaceHolders​(Map<String,​ClassNode> genericsSpec,
                                                                        GenericsType[] oldPlaceHolders)
        transforms generics types from an old context to a new context using the given spec. This method assumes all generics types will be placeholders. WARNING: The resulting generics types may or may not be placeholders after the transformation.
        Parameters:
        genericsSpec - the generics context information spec
        oldPlaceHolders - the old placeholders
        Returns:
        the new generics types
      • findParameterizedType

        public static ClassNode findParameterizedType​(ClassNode genericsClass,
                                                      ClassNode actualType,
                                                      boolean tryToFindExactType)
        Get the parameterized type by search the whole class hierarchy according to generics class and actual receiver. findParameterizedTypeFromCache(ClassNode, ClassNode, boolean) is strongly recommended for better performance.
        Parameters:
        genericsClass - the generics class
        actualType - the actual type
        tryToFindExactType - whether to try to find exact type
        Returns:
        the parameterized type
      • clearParameterizedTypeCache

        public static void clearParameterizedTypeCache()
        Clear the parameterized type cache It is useful to IDE as the type being compiled are continuously being edited/altered, see GROOVY-8675
      • makeDeclaringAndActualGenericsTypeMap

        public static Map<GenericsType,​GenericsType> makeDeclaringAndActualGenericsTypeMap​(ClassNode declaringClass,
                                                                                                 ClassNode actualReceiver)
        map declaring generics type to actual generics type, e.g. GROOVY-7204: declaring generics types: T, S extends Serializable actual generics types : String, Long the result map is [ T: String, S: Long ] The resolved types can not help us to choose methods correctly if the argument is a string: T: Object, S: Serializable so we need actual types: T: String, S: Long
      • makeDeclaringAndActualGenericsTypeMapOfExactType

        public static Map<GenericsType,​GenericsType> makeDeclaringAndActualGenericsTypeMapOfExactType​(ClassNode declaringClass,
                                                                                                            ClassNode actualReceiver)
        The method is similar with makeDeclaringAndActualGenericsTypeMap(ClassNode, ClassNode), The main difference is that the method will try to map all placeholders found to the relevant exact types, but the other will not try even if the parameterized type has placeholders
        Parameters:
        declaringClass - the generics class node declaring the generics types
        actualReceiver - the sub-class class node
        Returns:
        the placeholder-to-actualtype mapping
        Since:
        3.0.0
      • hasNonPlaceHolders

        public static boolean hasNonPlaceHolders​(ClassNode parameterizedType)
        Check whether the ClassNode has non generics placeholders, aka not placeholder
        Parameters:
        parameterizedType - the class node
        Returns:
        the result
        Since:
        3.0.0
      • hasPlaceHolders

        public static boolean hasPlaceHolders​(ClassNode parameterizedType)
        Check whether the ClassNode has generics placeholders
        Parameters:
        parameterizedType - the class node
        Returns:
        the result
        Since:
        3.0.0
      • parameterizeSAM

        public static Tuple2<ClassNode[],​ClassNode> parameterizeSAM​(ClassNode sam)
        Get the parameter and return types of the abstract method of SAM If the abstract method is not parameterized, we will get generics placeholders, e.g. T, U For example, the abstract method of Function is
              R apply(T t);
         
        We parameterize the above interface as Function<String, Integer>, then the abstract method will be
              Integer apply(String t);
         
        When we call parameterizeSAM on the ClassNode Function<String, Integer>, we can get parameter types and return type of the above abstract method, i.e. ClassNode ClassHelper.STRING_TYPE and ClassHelper.Integer_TYPE
        Parameters:
        sam - the class node which contains only one abstract method
        Returns:
        the parameter and return types
        Since:
        3.0.0