Interface Elements

public interface Elements

Utility methods for operating on program elements.

Compatibility Note: Methods may be added to this interface in future releases of the platform.

Since:
1.6
See Also:
ProcessingEnvironment.getElementUtils()

Nested Class Summary

Nested Classes
Modifier and Type Interface Description
static class  Elements.Origin

The origin of an element or other language model item.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type Method Description
List<? extends AnnotationMirror> getAllAnnotationMirrors​(Element e)

Returns all annotations present on an element, whether directly present or present via inheritance.
List<? extends Element> getAllMembers​(TypeElement type)

Returns all members of a type element, whether inherited or declared directly.
default Set<? extends ModuleElement> getAllModuleElements()

Returns all module elements in the current environment.
default Set<? extends PackageElement> getAllPackageElements​(CharSequence name)

Returns all package elements with the given canonical name.
default Set<? extends TypeElement> getAllTypeElements​(CharSequence name)

Returns all type elements with the given canonical name.
Name getBinaryName​(TypeElement type)

Returns the binary name of a type element.
String getConstantExpression​(Object value)

Returns the text of a constant expression representing a primitive value or a string.
String getDocComment​(Element e)

Returns the text of the documentation ("Javadoc") comment of an element.
Map<? extends ExecutableElement,​? extends AnnotationValue> getElementValuesWithDefaults​(AnnotationMirror a)

Returns the values of an annotation's elements, including defaults.
default ModuleElement getModuleElement​(CharSequence name)

Returns a module element given its fully qualified name.
default ModuleElement getModuleOf​(Element type)

Returns the module of an element.
Name getName​(CharSequence cs)

Return a name with the same sequence of characters as the argument.
default Elements.Origin getOrigin​(AnnotatedConstruct c, AnnotationMirror a)

Returns the origin of the given annotation mirror.
default Elements.Origin getOrigin​(Element e)

Returns the origin of the given element.
default Elements.Origin getOrigin​(ModuleElement m, ModuleElement.Directive directive)

Returns the origin of the given module directive.
PackageElement getPackageElement​(CharSequence name)

Returns a package given its fully qualified name if the package is unique in the environment.
default PackageElement getPackageElement​(ModuleElement module, CharSequence name)

Returns a package given its fully qualified name, as seen from the given module.
PackageElement getPackageOf​(Element type)

Returns the package of an element.
TypeElement getTypeElement​(CharSequence name)

Returns a type element given its canonical name if the type element is unique in the environment.
default TypeElement getTypeElement​(ModuleElement module, CharSequence name)

Returns a type element given its canonical name, as seen from the given module.
boolean hides​(Element hider, Element hidden)

Tests whether one type, method, or field hides another.
default boolean isBridge​(ExecutableElement e)

Returns true if the executable element is a bridge method, false otherwise.
boolean isDeprecated​(Element e)

Returns true if the element is deprecated, false otherwise.
boolean isFunctionalInterface​(TypeElement type)

Returns true if the type element is a functional interface, false otherwise.
boolean overrides​(ExecutableElement overrider, ExecutableElement overridden, TypeElement type)

Tests whether one method, as a member of a given type, overrides another method.
void printElements​(Writer w, Element... elements)

Prints a representation of the elements to the given writer in the specified order.

Method Detail

getPackageElement

PackageElement getPackageElement​(CharSequence name)

Returns a package given its fully qualified name if the package is unique in the environment. If running with modules, all modules in the modules graph are searched for matching packages.

Parameters:
name - fully qualified package name, or an empty string for an unnamed package
Returns:
the specified package, or null if it cannot be uniquely found

getPackageElement

default PackageElement getPackageElement​(ModuleElement module,
                                         CharSequence name)

Returns a package given its fully qualified name, as seen from the given module.

Implementation Requirements:
The default implementation of this method returns null.
Parameters:
name - fully qualified package name, or an empty string for an unnamed package
module - module relative to which the lookup should happen
Returns:
the specified package, or null if it cannot be found
Since:
9
See Also:
getAllPackageElements(java.lang.CharSequence)

getAllPackageElements

default Set<? extends PackageElement> getAllPackageElements​(CharSequence name)

Returns all package elements with the given canonical name. There may be more than one package element with the same canonical name if the package elements are in different modules.

Implementation Requirements:
The default implementation of this method calls getAllModuleElements and stores the result. If the set of modules is empty, getPackageElement(name) is called passing through the name argument. If getPackageElement(name) is null, an empty set of package elements is returned; otherwise, a single-element set with the found package element is returned. If the set of modules is nonempty, the modules are iterated over and any non-null results of getPackageElement(module, name) are accumulated into a set. The set is then returned.
Parameters:
name - the canonical name
Returns:
the package elements, or an empty set if no package with the name can be found
Since:
9
See Also:
getPackageElement(ModuleElement, CharSequence)

getTypeElement

TypeElement getTypeElement​(CharSequence name)

Returns a type element given its canonical name if the type element is unique in the environment. If running with modules, all modules in the modules graph are searched for matching type elements.

Parameters:
name - the canonical name
Returns:
the named type element, or null if it cannot be uniquely found

getTypeElement

default TypeElement getTypeElement​(ModuleElement module,
                                   CharSequence name)

Returns a type element given its canonical name, as seen from the given module.

Implementation Requirements:
The default implementation of this method returns null.
Parameters:
name - the canonical name
module - module relative to which the lookup should happen
Returns:
the named type element, or null if it cannot be found
Since:
9
See Also:
getAllTypeElements(java.lang.CharSequence)

getAllTypeElements

default Set<? extends TypeElement> getAllTypeElements​(CharSequence name)

Returns all type elements with the given canonical name. There may be more than one type element with the same canonical name if the type elements are in different modules.

Implementation Requirements:
The default implementation of this method calls getAllModuleElements and stores the result. If the set of modules is empty, getTypeElement(name) is called passing through the name argument. If getTypeElement(name) is null, an empty set of type elements is returned; otherwise, a single-element set with the found type element is returned. If the set of modules is nonempty, the modules are iterated over and any non-null results of getTypeElement(module, name) are accumulated into a set. The set is then returned.
Parameters:
name - the canonical name
Returns:
the type elements, or an empty set if no type with the name can be found
Since:
9
See Also:
getTypeElement(ModuleElement, CharSequence)

getModuleElement

default ModuleElement getModuleElement​(CharSequence name)

Returns a module element given its fully qualified name. If the named module cannot be found, null is returned. One situation where a module cannot be found is if the environment does not include modules, such as an annotation processing environment configured for a source version without modules.

Implementation Requirements:
The default implementation of this method returns null.
Parameters:
name - the name
Returns:
the named module element, or null if it cannot be found
Since:
9
See Also:
getAllModuleElements()

getAllModuleElements

default Set<? extends ModuleElement> getAllModuleElements()

Returns all module elements in the current environment. If no modules are present, an empty set is returned. One situation where no modules are present occurs when the environment does not include modules, such as an annotation processing environment configured for a source version without modules.

Implementation Requirements:
The default implementation of this method returns an empty set.
Returns:
the known module elements, or an empty set if there are no modules
Since:
9
See Also:
getModuleElement(CharSequence)

getElementValuesWithDefaults

Map<? extends ExecutableElement,​? extends AnnotationValue> getElementValuesWithDefaults​(AnnotationMirror a)

Returns the values of an annotation's elements, including defaults.

Parameters:
a - annotation to examine
Returns:
the values of the annotation's elements, including defaults
See Also:
AnnotationMirror.getElementValues()

getDocComment

String getDocComment​(Element e)

Returns the text of the documentation ("Javadoc") comment of an element.

A documentation comment of an element is a comment that begins with "/**" , ends with a separate "*/", and immediately precedes the element, ignoring white space. Therefore, a documentation comment contains at least three"*" characters. The text returned for the documentation comment is a processed form of the comment as it appears in source code. The leading " /**" and trailing "*/" are removed. For lines of the comment starting after the initial "/**", leading white space characters are discarded as are any consecutive "*" characters appearing after the white space or starting the line. The processed lines are then concatenated together (including line terminators) and returned.

Parameters:
e - the element being examined
Returns:
the documentation comment of the element, or null if there is none

isDeprecated

boolean isDeprecated​(Element e)

Returns true if the element is deprecated, false otherwise.

Parameters:
e - the element being examined
Returns:
true if the element is deprecated, false otherwise

getOrigin

default Elements.Origin getOrigin​(Element e)

Returns the origin of the given element.

Note that if this method returns EXPLICIT and the element was created from a class file, then the element may not, in fact, correspond to an explicitly declared construct in source code. This is due to limitations of the fidelity of the class file format in preserving information from source code. For example, at least some versions of the class file format do not preserve whether a constructor was explicitly declared by the programmer or was implicitly declared as the default constructor.

Implementation Requirements:
The default implementation of this method returns EXPLICIT.
Parameters:
e - the element being examined
Returns:
the origin of the given element
Since:
9

getOrigin

default Elements.Origin getOrigin​(AnnotatedConstruct c,
                                  AnnotationMirror a)

Returns the origin of the given annotation mirror. An annotation mirror is mandated if it is an implicitly declared container annotation used to hold repeated annotations of a repeatable annotation type.

Note that if this method returns EXPLICIT and the annotation mirror was created from a class file, then the element may not, in fact, correspond to an explicitly declared construct in source code. This is due to limitations of the fidelity of the class file format in preserving information from source code. For example, at least some versions of the class file format do not preserve whether an annotation was explicitly declared by the programmer or was implicitly declared as a container annotation.

Implementation Requirements:
The default implementation of this method returns EXPLICIT.
Parameters:
c - the construct the annotation mirror modifies
a - the annotation mirror being examined
Returns:
the origin of the given annotation mirror
Since:
9

getOrigin

default Elements.Origin getOrigin​(ModuleElement m,
                                  ModuleElement.Directive directive)

Returns the origin of the given module directive.

Note that if this method returns EXPLICIT and the module directive was created from a class file, then the module directive may not, in fact, correspond to an explicitly declared construct in source code. This is due to limitations of the fidelity of the class file format in preserving information from source code. For example, at least some versions of the class file format do not preserve whether a uses directive was explicitly declared by the programmer or was added as a synthetic construct.

Note that an implementation may not be able to reliably determine the origin status of the directive if the directive is created from a class file due to limitations of the fidelity of the class file format in preserving information from source code.

Implementation Requirements:
The default implementation of this method returns EXPLICIT.
Parameters:
m - the module of the directive
directive - the module directive being examined
Returns:
the origin of the given directive
Since:
9

isBridge

default boolean isBridge​(ExecutableElement e)

Returns true if the executable element is a bridge method, false otherwise.

Implementation Requirements:
The default implementation of this method returns false.
Parameters:
e - the executable being examined
Returns:
true if the executable element is a bridge method, false otherwise
Since:
9

getBinaryName

Name getBinaryName​(TypeElement type)

Returns the binary name of a type element.

Parameters:
type - the type element being examined
Returns:
the binary name
See Also:
TypeElement.getQualifiedName()

getPackageOf

PackageElement getPackageOf​(Element type)

Returns the package of an element. The package of a package is itself.

Parameters:
type - the element being examined
Returns:
the package of an element

getModuleOf

default ModuleElement getModuleOf​(Element type)

Returns the module of an element. The module of a module is itself. If there is no module for the element, null is returned. One situation where there is no module for an element is if the environment does not include modules, such as an annotation processing environment configured for a source version without modules.

Implementation Requirements:
The default implementation of this method returns null.
Parameters:
type - the element being examined
Returns:
the module of an element
Since:
9

getAllMembers

List<? extends Element> getAllMembers​(TypeElement type)

Returns all members of a type element, whether inherited or declared directly. For a class the result also includes its constructors, but not local or anonymous classes.

API Note:
Elements of certain kinds can be isolated using methods in ElementFilter.
Parameters:
type - the type being examined
Returns:
all members of the type
See Also:
Element.getEnclosedElements()

getAllAnnotationMirrors

List<? extends AnnotationMirror> getAllAnnotationMirrors​(Element e)

Returns all annotations present on an element, whether directly present or present via inheritance.

Parameters:
e - the element being examined
Returns:
all annotations of the element
See Also:
Element.getAnnotationMirrors(), AnnotatedConstruct

hides

boolean hides​(Element hider,
              Element hidden)

Tests whether one type, method, or field hides another.

Parameters:
hider - the first element
hidden - the second element
Returns:
true if and only if the first element hides the second

overrides

boolean overrides​(ExecutableElement overrider,
                  ExecutableElement overridden,
                  TypeElement type)

Tests whether one method, as a member of a given type, overrides another method. When a non-abstract method overrides an abstract one, the former is also said to implement the latter.

In the simplest and most typical usage, the value of the type parameter will simply be the class or interface directly enclosing overrider (the possibly-overriding method). For example, suppose m1 represents the method String.hashCode and m2 represents Object.hashCode. We can then ask whether m1 overrides m2 within the class String (it does): 

assert elements.overrides(m1, m2, elements.getTypeElement("java.lang.String"));
A more interesting case can be illustrated by the following example in which a method in type A does not override a like-named method in type B: 
class A { public void m() {} } interface B { void m(); } ... m1 = ...; // A.m m2 = ...; // B.m assert ! elements.overrides(m1, m2, elements.getTypeElement("A"));
When viewed as a member of a third type C, however, the method in A does override the one in B: 
class C extends A implements B {} ... assert elements.overrides(m1, m2, elements.getTypeElement("C"));
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

getConstantExpression

String getConstantExpression​(Object value)

Returns the text of a constant expression representing a primitive value or a string. The text returned is in a form suitable for representing the value in source code.

Parameters:
value - a primitive value or string
Returns:
the text of a constant expression
Throws:
IllegalArgumentException - if the argument is not a primitive value or string
See Also:
VariableElement.getConstantValue()

printElements

void printElements​(Writer w,
                   Element... elements)

Prints a representation of the elements to the given writer in the specified order. The main purpose of this method is for diagnostics. The exact format of the output is not specified and is subject to change.

Parameters:
w - the writer to print the output to
elements - the elements to print

getName

Name getName​(CharSequence cs)

Return a name with the same sequence of characters as the argument.

Parameters:
cs - the character sequence to return as a name
Returns:
a name with the same sequence of characters as the argument

isFunctionalInterface

boolean isFunctionalInterface​(TypeElement type)

Returns true if the type element is a functional interface, false otherwise.

Parameters:
type - the type element being examined
Returns:
true if the element is a functional interface, false otherwise
Since:
1.8