Class Parameter
- java.lang.Object
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- com.google.common.reflect.Parameter
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- All Implemented Interfaces:
AnnotatedElement
@Beta public final class Parameter extends Object implements AnnotatedElement
Represents a method or constructor parameter.Note: Since Java 8 introduced
Parameter
to represent method and constructor parameters, this class is no longer necessary. We intend to deprecate it in a future version.- Since:
- 14.0
- Author:
- Ben Yu
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
equals(Object obj)
Indicates whether some other object is "equal to" this one.AnnotatedType
getAnnotatedType()
<A extends Annotation>
AgetAnnotation(Class<A> annotationType)
Returns this element's annotation for the specified type if such an annotation is present, else null.Annotation[]
getAnnotations()
Returns annotations that are present on this element.<A extends Annotation>
A[]getAnnotationsByType(Class<A> annotationType)
Returns annotations that are associated with this element.<A extends Annotation>
AgetDeclaredAnnotation(Class<A> annotationType)
Returns this element's annotation for the specified type if such an annotation is directly present, else null.Annotation[]
getDeclaredAnnotations()
Returns annotations that are directly present on this element.<A extends Annotation>
A[]getDeclaredAnnotationsByType(Class<A> annotationType)
Returns this element's annotation(s) for the specified type if such annotations are either directly present or indirectly present.Invokable<?,?>
getDeclaringInvokable()
Returns theInvokable
that declares this parameter.TypeToken<?>
getType()
Returns the type of the parameter.int
hashCode()
Returns a hash code value for the object.boolean
isAnnotationPresent(Class<? extends Annotation> annotationType)
Returns true if an annotation for the specified type is present on this element, else false.String
toString()
Returns a string representation of the object.
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Method Detail
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getDeclaringInvokable
public Invokable<?,?> getDeclaringInvokable()
Returns theInvokable
that declares this parameter.
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isAnnotationPresent
public boolean isAnnotationPresent(Class<? extends Annotation> annotationType)
Description copied from interface:java.lang.reflect.AnnotatedElement
Returns true if an annotation for the specified type is present on this element, else false. This method is designed primarily for convenient access to marker annotations.The truth value returned by this method is equivalent to:
getAnnotation(annotationClass) != null
The body of the default method is specified to be the code above.
- Specified by:
isAnnotationPresent
in interfaceAnnotatedElement
- Parameters:
annotationType
- the Class object corresponding to the annotation type- Returns:
- true if an annotation for the specified annotation type is present on this element, else false
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getAnnotation
@CheckForNull public <A extends Annotation> A getAnnotation(Class<A> annotationType)
Description copied from interface:java.lang.reflect.AnnotatedElement
Returns this element's annotation for the specified type if such an annotation is present, else null.- Specified by:
getAnnotation
in interfaceAnnotatedElement
- Type Parameters:
A
- the type of the annotation to query for and return if present- Parameters:
annotationType
- 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
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getAnnotations
public Annotation[] getAnnotations()
Description copied from interface:java.lang.reflect.AnnotatedElement
Returns annotations that are present on this element. If there are no annotations present on this element, the return value is an array of length 0. 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:
getAnnotations
in interfaceAnnotatedElement
- Returns:
- annotations present on this element
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getAnnotationsByType
public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationType)
Description copied from interface:java.lang.reflect.AnnotatedElement
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 andAnnotatedElement.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:
A
- the type of the annotation to query for and return if present- Parameters:
annotationType
- 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
- Since:
- 18.0
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getDeclaredAnnotations
public Annotation[] getDeclaredAnnotations()
Description copied from interface:java.lang.reflect.AnnotatedElement
Returns annotations that are directly present on this element. This method ignores inherited annotations. If there are no annotations directly present on this element, the return value is an array of length 0. 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:
getDeclaredAnnotations
in interfaceAnnotatedElement
- Returns:
- annotations directly present on this element
- Since:
- 18.0
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getDeclaredAnnotation
@CheckForNull public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationType)
Description copied from interface:java.lang.reflect.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:
A
- the type of the annotation to query for and return if directly present- Parameters:
annotationType
- 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
- Since:
- 18.0
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getDeclaredAnnotationsByType
public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationType)
Description copied from interface:java.lang.reflect.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 andAnnotatedElement.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:
A
- the type of the annotation to query for and return if directly or indirectly present- Parameters:
annotationType
- 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
- Since:
- 18.0
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getAnnotatedType
public AnnotatedType getAnnotatedType()
- Since:
- 25.1
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equals
public boolean equals(@CheckForNull Object obj)
Description copied from class:java.lang.Object
Indicates whether some other object is "equal to" this one.The
equals
method implements an equivalence relation on non-null object references:- It is reflexive: for any non-null reference value
x
,x.equals(x)
should returntrue
. - It is symmetric: for any non-null reference values
x
andy
,x.equals(y)
should returntrue
if and only ify.equals(x)
returnstrue
. - It is transitive: for any non-null reference values
x
,y
, andz
, ifx.equals(y)
returnstrue
andy.equals(z)
returnstrue
, thenx.equals(z)
should returntrue
. - It is consistent: for any non-null reference values
x
andy
, multiple invocations ofx.equals(y)
consistently returntrue
or consistently returnfalse
, provided no information used inequals
comparisons on the objects is modified. - For any non-null reference value
x
,x.equals(null)
should returnfalse
.
The
equals
method for classObject
implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference valuesx
andy
, this method returnstrue
if and only ifx
andy
refer to the same object (x == y
has the valuetrue
).Note that it is generally necessary to override the
hashCode
method whenever this method is overridden, so as to maintain the general contract for thehashCode
method, which states that equal objects must have equal hash codes.- Overrides:
equals
in classObject
- Parameters:
obj
- the reference object with which to compare.- Returns:
true
if this object is the same as the obj argument;false
otherwise.- See Also:
Object.hashCode()
,HashMap
- It is reflexive: for any non-null reference value
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hashCode
public int hashCode()
Description copied from class:java.lang.Object
Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided byHashMap
.The general contract of
hashCode
is:- Whenever it is invoked on the same object more than once during
an execution of a Java application, the
hashCode
method must consistently return the same integer, provided no information used inequals
comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. - If two objects are equal according to the
equals(Object)
method, then calling thehashCode
method on each of the two objects must produce the same integer result. - It is not required that if two objects are unequal
according to the
Object.equals(java.lang.Object)
method, then calling thehashCode
method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.
As much as is reasonably practical, the hashCode method defined by class
Object
does return distinct integers for distinct objects. (The hashCode may or may not be implemented as some function of an object's memory address at some point in time.)- Overrides:
hashCode
in classObject
- Returns:
- a hash code value for this object.
- See Also:
Object.equals(java.lang.Object)
,System.identityHashCode(java.lang.Object)
- Whenever it is invoked on the same object more than once during
an execution of a Java application, the
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toString
public String toString()
Description copied from class:java.lang.Object
Returns a string representation of the object. In general, thetoString
method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.The
toString
method for classObject
returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@
', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:getClass().getName() + '@' + Integer.toHexString(hashCode())
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