Class Parameter
- java.lang.Object
-
- java.lang.reflect.Parameter
- All Implemented Interfaces:
AnnotatedElement
public final class Parameter extends Object implements AnnotatedElement
Information about method parameters. A Parameter
provides information about method parameters, including its name and modifiers. It also provides an alternate means of obtaining attributes for the parameter.
- Since:
- 1.8
Method Summary
Modifier and Type | Method | Description |
---|---|---|
boolean | equals(Object obj) | Compares based on the executable and the index. |
AnnotatedType | getAnnotatedType() | Returns an AnnotatedType object that represents the use of a type to specify the type of the formal parameter represented by this Parameter. |
<T extends Annotation> | getAnnotation(Class<T> annotationClass) | Returns this element's annotation for the specified type if such an annotation is present, else null. |
<T extends Annotation> | getAnnotationsByType(Class<T> annotationClass) | Returns annotations that are associated with this element. |
<T extends Annotation> | getDeclaredAnnotation(Class<T> annotationClass) | Returns this element's annotation for the specified type if such an annotation is directly present, else null. |
<T extends Annotation> | getDeclaredAnnotationsByType(Class<T> annotationClass) | Returns this element's annotation(s) for the specified type if such annotations are either directly present or indirectly present. |
Executable | getDeclaringExecutable() | Return the |
int | getModifiers() | Get the modifier flags for this the parameter represented by this |
String | getName() | Returns the name of the parameter. |
Type | getParameterizedType() | Returns a |
Class<?> | getType() | Returns a |
int | hashCode() | Returns a hash code based on the executable's hash code and the index. |
boolean | isImplicit() | Returns |
boolean | isNamePresent() | Returns true if the parameter has a name according to the class file; returns false otherwise. |
boolean | isSynthetic() | Returns |
boolean | isVarArgs() | Returns |
String | toString() | Returns a string describing this parameter. |
Methods declared in class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods declared in interface java.lang.reflect.AnnotatedElement
getAnnotations, getDeclaredAnnotations, isAnnotationPresent
Method Detail
equals
public boolean equals(Object obj)
Compares based on the executable and the index.
- Overrides:
-
equals
in classObject
- Parameters:
-
obj
- The object to compare. - Returns:
- Whether or not this is equal to the argument.
- See Also:
-
Object.hashCode()
,HashMap
hashCode
public int hashCode()
Returns a hash code based on the executable's hash code and the index.
- Overrides:
-
hashCode
in classObject
- Returns:
- A hash code based on the executable's hash code.
- See Also:
-
Object.equals(java.lang.Object)
,System.identityHashCode(java.lang.Object)
isNamePresent
public boolean isNamePresent()
Returns true if the parameter has a name according to the class file; returns false otherwise. Whether a parameter has a name is determined by the MethodParameters attribute of the method which declares the parameter.
- Returns:
- true if and only if the parameter has a name according to the class file.
toString
public String toString()
Returns a string describing this parameter. The format is the modifiers for the parameter, if any, in canonical order as recommended by The Java™ Language Specification, followed by the fully- qualified type of the parameter (excluding the last [] if the parameter is variable arity), followed by "..." if the parameter is variable arity, followed by a space, followed by the name of the parameter.
- Overrides:
-
toString
in classObject
- Returns:
- A string representation of the parameter and associated information.
getDeclaringExecutable
public Executable getDeclaringExecutable()
Return the Executable
which declares this parameter.
- Returns:
- The
Executable
declaring this parameter.
getModifiers
public int getModifiers()
Get the modifier flags for this the parameter represented by this Parameter
object.
- Returns:
- The modifier flags for this parameter.
getName
public String getName()
Returns the name of the parameter. If the parameter's name is present, then this method returns the name provided by the class file. Otherwise, this method synthesizes a name of the form argN, where N is the index of the parameter in the descriptor of the method which declares the parameter.
- Returns:
- The name of the parameter, either provided by the class file or synthesized if the class file does not provide a name.
getParameterizedType
public Type getParameterizedType()
Returns a Type
object that identifies the parameterized type for the parameter represented by this Parameter
object.
- Returns:
- a
Type
object identifying the parameterized type of the parameter represented by this object
getType
public Class<?> getType()
Returns a Class
object that identifies the declared type for the parameter represented by this Parameter
object.
- Returns:
- a
Class
object identifying the declared type of the parameter represented by this object
getAnnotatedType
public AnnotatedType getAnnotatedType()
Returns an AnnotatedType object that represents the use of a type to specify the type of the formal parameter represented by this Parameter.
- Returns:
- an
AnnotatedType
object representing the use of a type to specify the type of the formal parameter represented by this Parameter
isImplicit
public boolean isImplicit()
Returns true
if this parameter is implicitly declared in source code; returns false
otherwise.
- Returns:
- true if and only if this parameter is implicitly declared as defined by The Java™ Language Specification.
isSynthetic
public boolean isSynthetic()
Returns true
if this parameter is neither implicitly nor explicitly declared in source code; returns false
otherwise.
- Returns:
- true if and only if this parameter is a synthetic construct as defined by The Java™ Language Specification.
isVarArgs
public boolean isVarArgs()
Returns true
if this parameter represents a variable argument list; returns false
otherwise.
- Returns:
-
true
if an only if this parameter represents a variable argument list.
getAnnotation
public <T extends Annotation> T getAnnotation(Class<T> annotationClass)
Returns this element's annotation for the specified type if such an annotation is present, else null.
- Specified by:
-
getAnnotation
in interfaceAnnotatedElement
- Type Parameters:
-
T
- the type of the annotation to query for and return if present - Parameters:
-
annotationClass
- the Class object corresponding to the annotation type - Returns:
- this element's annotation for the specified annotation type if present on this element, else null
- Throws:
-
NullPointerException
- if the given annotation class is null
getAnnotationsByType
public <T extends Annotation> T[] getAnnotationsByType(Class<T> annotationClass)
Returns annotations that are associated with this element. If there are no annotations associated with this element, the return value is an array of length 0. The difference between this method and AnnotatedElement.getAnnotation(Class)
is that this method detects if its argument is a repeatable annotation type (JLS 9.6), and if so, attempts to find one or more annotations of that type by "looking through" a container annotation. The caller of this method is free to modify the returned array; it will have no effect on the arrays returned to other callers.
- Specified by:
-
getAnnotationsByType
in interfaceAnnotatedElement
- Type Parameters:
-
T
- the type of the annotation to query for and return if present - Parameters:
-
annotationClass
- the Class object corresponding to the annotation type - Returns:
- all this element's annotations for the specified annotation type if associated with this element, else an array of length zero
- Throws:
-
NullPointerException
- if the given annotation class is null
getDeclaredAnnotation
public <T extends Annotation> T getDeclaredAnnotation(Class<T> annotationClass)
Description copied from interface: AnnotatedElement
Returns this element's annotation for the specified type if such an annotation is directly present, else null. This method ignores inherited annotations. (Returns null if no annotations are directly present on this element.)
- Specified by:
-
getDeclaredAnnotation
in interfaceAnnotatedElement
- Type Parameters:
-
T
- the type of the annotation to query for and return if directly present - Parameters:
-
annotationClass
- the Class object corresponding to the annotation type - Returns:
- this element's annotation for the specified annotation type if directly present on this element, else null
- Throws:
-
NullPointerException
- if the given annotation class is null
getDeclaredAnnotationsByType
public <T extends Annotation> T[] getDeclaredAnnotationsByType(Class<T> annotationClass)
Description copied from interface: AnnotatedElement
Returns this element's annotation(s) for the specified type if such annotations are either directly present or indirectly present. This method ignores inherited annotations. If there are no specified annotations directly or indirectly present on this element, the return value is an array of length 0. The difference between this method and AnnotatedElement.getDeclaredAnnotation(Class)
is that this method detects if its argument is a repeatable annotation type (JLS 9.6), and if so, attempts to find one or more annotations of that type by "looking through" a container annotation if one is present. The caller of this method is free to modify the returned array; it will have no effect on the arrays returned to other callers.
- Specified by:
-
getDeclaredAnnotationsByType
in interfaceAnnotatedElement
- Type Parameters:
-
T
- the type of the annotation to query for and return if directly or indirectly present - Parameters:
-
annotationClass
- the Class object corresponding to the annotation type - Returns:
- all this element's annotations for the specified annotation type if directly or indirectly present on this element, else an array of length zero
- Throws:
-
NullPointerException
- if the given annotation class is null