Class MoreElements


  • @Beta
    public final class MoreElements
    extends Object
    Static utility methods pertaining to Element instances.
    Author:
    Gregory Kick
    • Method Detail

      • isType

        public static boolean isType​(Element element)
        Returns true if the given Element instance is a TypeElement.

        This method is functionally equivalent to an instanceof check, but should always be used over that idiom as instructed in the documentation for Element.

        Throws:
        NullPointerException - if element is null
      • hasModifiers

        public static <T extends Element> com.google.common.base.Predicate<T> hasModifiers​(Modifier... modifiers)
        Returns a Predicate that can be used to filter elements by Modifier. The predicate returns true if the input Element has all of the given modifiers, perhaps in addition to others.

        Here is an example how one could get a List of static methods of a class:

        
         FluentIterable.from(ElementFilter.methodsIn(clazzElement.getEnclosedElements()))
             .filter(MoreElements.hasModifiers(Modifier.STATIC).toList();
         
      • hasModifiers

        public static <T extends Element> com.google.common.base.Predicate<T> hasModifiers​(Set<Modifier> modifiers)
        Returns a Predicate that can be used to filter elements by Modifier. The predicate returns true if the input Element has all of the given modifiers, perhaps in addition to others.

        Here is an example how one could get a List of methods with certain modifiers of a class:

        
         Set<Modifier> modifiers = ...;
         FluentIterable.from(ElementFilter.methodsIn(clazzElement.getEnclosedElements()))
             .filter(MoreElements.hasModifiers(modifiers).toList();
         
      • getLocalAndInheritedMethods

        @Deprecated
        public static com.google.common.collect.ImmutableSet<ExecutableElement> getLocalAndInheritedMethods​(TypeElement type,
                                                                                                            Elements elementUtils)
        Deprecated.
        The method getLocalAndInheritedMethods(TypeElement, Types, Elements) has better consistency between Java compilers.
        Returns the set of all non-private, non-static methods from type, including methods that it inherits from its ancestors. Inherited methods that are overridden are not included in the result. So if type defines public String toString(), the returned set will contain that method, but not the toString() method defined by Object.

        The returned set may contain more than one method with the same signature, if type inherits those methods from different ancestors. For example, if it inherits from unrelated interfaces One and Two which each define void foo();, and if it does not itself override the foo() method, then both One.foo() and Two.foo() will be in the returned set.

        The order of the returned set is deterministic: within a class or interface, methods are in the order they appear in the source code; methods in ancestors come before methods in descendants; methods in interfaces come before methods in classes; and in a class or interface that has more than one superinterface, the interfaces are in the order of their appearance in implements or extends.

        Parameters:
        type - the type whose own and inherited methods are to be returned
        elementUtils - an Elements object, typically returned by processingEnv.getElementUtils()
      • getLocalAndInheritedMethods

        public static com.google.common.collect.ImmutableSet<ExecutableElement> getLocalAndInheritedMethods​(TypeElement type,
                                                                                                            Types typeUtils,
                                                                                                            Elements elementUtils)
        Returns the set of all non-private, non-static methods from type, including methods that it inherits from its ancestors. Inherited methods that are overridden are not included in the result. So if type defines public String toString(), the returned set will contain that method, but not the toString() method defined by Object.

        The returned set may contain more than one method with the same signature, if type inherits those methods from different ancestors. For example, if it inherits from unrelated interfaces One and Two which each define void foo();, and if it does not itself override the foo() method, then both One.foo() and Two.foo() will be in the returned set.

        The order of the returned set is deterministic: within a class or interface, methods are in the order they appear in the source code; methods in ancestors come before methods in descendants; methods in interfaces come before methods in classes; and in a class or interface that has more than one superinterface, the interfaces are in the order of their appearance in implements or extends.

        Parameters:
        type - the type whose own and inherited methods are to be returned
        typeUtils - a Types object, typically returned by processingEnv.getTypeUtils()
        elementUtils - an Elements object, typically returned by processingEnv.getElementUtils()
      • overrides

        public static boolean overrides​(ExecutableElement overrider,
                                        ExecutableElement overridden,
                                        TypeElement type,
                                        Types typeUtils)
        Tests whether one method, as a member of a given type, overrides another method.

        This method does the same thing as Elements.overrides(ExecutableElement, ExecutableElement, TypeElement), but in a way that is more consistent between compilers, in particular between javac and ecj (the Eclipse compiler).

        Parameters:
        overrider - the first method, possible overrider
        overridden - the second method, possibly being overridden
        type - the type of which the first method is a member
        Returns:
        true if and only if the first method overrides the second
      • getAllMethods

        public static com.google.common.collect.ImmutableSet<ExecutableElement> getAllMethods​(TypeElement type,
                                                                                              Types typeUtils,
                                                                                              Elements elementUtils)
        Returns the set of all methods from type, including methods that it inherits from its ancestors. Inherited methods that are overridden are not included in the result. So if type defines public String toString(), the returned set will contain that method, but not the toString() method defined by Object.

        The returned set may contain more than one method with the same signature, if type inherits those methods from different ancestors. For example, if it inherits from unrelated interfaces One and Two which each define void foo();, and if it does not itself override the foo() method, then both One.foo() and Two.foo() will be in the returned set.

        The order of the returned set is deterministic: within a class or interface, methods are in the order they appear in the source code; methods in ancestors come before methods in descendants; methods in interfaces come before methods in classes; and in a class or interface that has more than one superinterface, the interfaces are in the order of their appearance in implements or extends.

        Parameters:
        type - the type whose own and inherited methods are to be returned
        typeUtils - a Types object, typically returned by processingEnv.getTypeUtils()
        elementUtils - an Elements object, typically returned by processingEnv.getElementUtils()