T
- the type that owns this method or constructor.R
- the return type of (or supertype thereof) the method or the declaring type of the
constructor.@Beta public abstract class Invokable<T,R> extends AccessibleObject implements GenericDeclaration
Method
or a Constructor
.
Convenience API is provided to make common reflective operation easier to deal with,
such as isPublic()
, getParameters()
etc.
In addition to convenience methods, TypeToken.method(java.lang.reflect.Method)
and TypeToken.constructor(java.lang.reflect.Constructor<?>)
will resolve the type parameters of the method or constructor in the
context of the owner type, which may be a subtype of the declaring class. For example:
Method getMethod = List.class.getMethod("get", int.class);
Invokable<List<String>, ?> invokable = new TypeToken<List<String>>() {}.method(getMethod);
assertEquals(TypeToken.of(String.class), invokable.getReturnType()); // Not Object.class!
assertEquals(new TypeToken<List<String>>() {}, invokable.getOwnerType());
Modifier and Type | Method and Description |
---|---|
boolean |
equals(Object obj)
Indicates whether some other object is "equal to" this one.
|
static <T> Invokable<T,T> |
from(Constructor<T> constructor)
Returns
Invokable of constructor . |
static Invokable<?,Object> |
from(Method method)
Returns
Invokable of method . |
<A extends Annotation> |
getAnnotation(Class<A> annotationClass)
Returns this element's annotation for the specified type if
such an annotation is present, else null.
|
Annotation[] |
getAnnotations()
Returns all annotations present on this element.
|
Annotation[] |
getDeclaredAnnotations()
Returns all annotations that are directly present on this
element.
|
Class<? super T> |
getDeclaringClass()
Returns the Class object representing the class or interface
that declares the member or constructor represented by this Member.
|
ImmutableList<TypeToken<? extends Throwable>> |
getExceptionTypes()
Returns all declared exception types of this
Invokable . |
int |
getModifiers()
Returns the Java language modifiers for the member or
constructor represented by this Member, as an integer.
|
String |
getName()
Returns the simple name of the underlying member or constructor
represented by this Member.
|
TypeToken<T> |
getOwnerType()
Returns the type of
T . |
ImmutableList<Parameter> |
getParameters()
Returns all declared parameters of this
Invokable . |
TypeToken<? extends R> |
getReturnType()
Returns the return type of this
Invokable . |
int |
hashCode()
Returns a hash code value for the object.
|
R |
invoke(T receiver,
Object... args)
Invokes with
receiver as 'this' and args passed to the underlying method
and returns the return value; or calls the underlying constructor with args and returns
the constructed instance. |
boolean |
isAbstract()
Returns true if the method is abstract.
|
boolean |
isAccessible()
Get the value of the
accessible flag for this object. |
boolean |
isAnnotationPresent(Class<? extends Annotation> annotationClass)
Returns true if an annotation for the specified type
is present on this element, else false.
|
boolean |
isFinal()
Returns
true if this method is final, per Modifier.isFinal(getModifiers()) . |
boolean |
isNative()
Returns true if the element is native.
|
abstract boolean |
isOverridable()
Returns
true if this is an overridable method. |
boolean |
isPackagePrivate()
Returns true if the element is package-private.
|
boolean |
isPrivate()
Returns true if the element is private.
|
boolean |
isProtected()
Returns true if the element is protected.
|
boolean |
isPublic()
Returns true if the element is public.
|
boolean |
isStatic()
Returns true if the element is static.
|
boolean |
isSynchronized()
Returns true if the method is synchronized.
|
boolean |
isSynthetic()
Returns
true if this member was introduced by
the compiler; returns false otherwise. |
abstract boolean |
isVarArgs()
Returns
true if this was declared to take a variable number of arguments. |
<R1 extends R> |
returning(Class<R1> returnType)
Explicitly specifies the return type of this
Invokable . |
<R1 extends R> |
returning(TypeToken<R1> returnType)
Explicitly specifies the return type of this
Invokable . |
void |
setAccessible(boolean flag)
Set the
accessible flag for this object to
the indicated boolean value. |
String |
toString()
Returns a string representation of the object.
|
setAccessible
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
getTypeParameters
public static <T> Invokable<T,T> from(Constructor<T> constructor)
Invokable
of constructor
.public abstract boolean isOverridable()
true
if this is an overridable method. Constructors, private, static or final
methods, or methods declared by final classes are not overridable.public abstract boolean isVarArgs()
true
if this was declared to take a variable number of arguments.public final R invoke(@Nullable T receiver, Object... args) throws InvocationTargetException, IllegalAccessException
receiver
as 'this' and args
passed to the underlying method
and returns the return value; or calls the underlying constructor with args
and returns
the constructed instance.IllegalAccessException
- if this Constructor
object enforces Java language
access control and the underlying method or constructor is inaccessible.IllegalArgumentException
- if the number of actual and formal parameters differ;
if an unwrapping conversion for primitive arguments fails; or if, after possible
unwrapping, a parameter value cannot be converted to the corresponding formal
parameter type by a method invocation conversion.InvocationTargetException
- if the underlying method or constructor throws an exception.public final TypeToken<? extends R> getReturnType()
Invokable
.public final ImmutableList<Parameter> getParameters()
Invokable
. Note that if this is a constructor
of a non-static inner class, unlike Constructor.getParameterTypes()
, the hidden
this
parameter of the enclosing class is excluded from the returned parameters.public final ImmutableList<TypeToken<? extends Throwable>> getExceptionTypes()
Invokable
.public final <R1 extends R> Invokable<T,R1> returning(Class<R1> returnType)
Invokable
. For example:
Method factoryMethod = Person.class.getMethod("create");
Invokable<?, Person> factory = Invokable.of(getNameMethod).returning(Person.class);
public final <R1 extends R> Invokable<T,R1> returning(TypeToken<R1> returnType)
Invokable
.public final Class<? super T> getDeclaringClass()
java.lang.reflect.Member
getDeclaringClass
in interface Member
public TypeToken<T> getOwnerType()
T
.public final boolean isAnnotationPresent(Class<? extends Annotation> annotationClass)
java.lang.reflect.AnnotatedElement
isAnnotationPresent
in interface AnnotatedElement
isAnnotationPresent
in class AccessibleObject
annotationClass
- the Class object corresponding to the
annotation typepublic final <A extends Annotation> A getAnnotation(Class<A> annotationClass)
java.lang.reflect.AnnotatedElement
getAnnotation
in interface AnnotatedElement
getAnnotation
in class AccessibleObject
annotationClass
- the Class object corresponding to the
annotation typepublic final Annotation[] getAnnotations()
java.lang.reflect.AnnotatedElement
getAnnotations
in interface AnnotatedElement
getAnnotations
in class AccessibleObject
public final Annotation[] getDeclaredAnnotations()
java.lang.reflect.AnnotatedElement
getDeclaredAnnotations
in interface AnnotatedElement
getDeclaredAnnotations
in class AccessibleObject
public final void setAccessible(boolean flag) throws SecurityException
java.lang.reflect.AccessibleObject
accessible
flag for this object to
the indicated boolean value. A value of true
indicates that
the reflected object should suppress Java language access
checking when it is used. A value of false
indicates
that the reflected object should enforce Java language access checks.
First, if there is a security manager, its
checkPermission
method is called with a
ReflectPermission("suppressAccessChecks")
permission.
A SecurityException
is raised if flag
is
true
but accessibility of this object may not be changed
(for example, if this element object is a Constructor
object for
the class Class
).
A SecurityException
is raised if this object is a Constructor
object for the class
java.lang.Class
, and flag
is true.
setAccessible
in class AccessibleObject
flag
- the new value for the accessible
flagSecurityException
- if the request is denied.SecurityManager.checkPermission(java.security.Permission)
,
RuntimePermission
public final boolean isAccessible()
java.lang.reflect.AccessibleObject
accessible
flag for this object.isAccessible
in class AccessibleObject
accessible
flagpublic final String getName()
java.lang.reflect.Member
public final int getModifiers()
java.lang.reflect.Member
getModifiers
in interface Member
Modifier
public final boolean isSynthetic()
java.lang.reflect.Member
true
if this member was introduced by
the compiler; returns false
otherwise.isSynthetic
in interface Member
public final boolean isPublic()
public final boolean isProtected()
public final boolean isPackagePrivate()
public final boolean isPrivate()
public final boolean isStatic()
public final boolean isFinal()
true
if this method is final, per Modifier.isFinal(getModifiers())
.
Note that a method may still be effectively "final", or non-overridable when it has no
final
keyword. For example, it could be private, or it could be declared by a final
class. To tell whether a method is overridable, use isOverridable()
.
public final boolean isAbstract()
public final boolean isNative()
public final boolean isSynchronized()
public boolean equals(@Nullable Object obj)
java.lang.Object
The equals
method implements an equivalence relation
on non-null object references:
x
, x.equals(x)
should return
true
.
x
and y
, x.equals(y)
should return true
if and only if
y.equals(x)
returns true
.
x
, y
, and z
, if
x.equals(y)
returns true
and
y.equals(z)
returns true
, then
x.equals(z)
should return true
.
x
and y
, multiple invocations of
x.equals(y)
consistently return true
or consistently return false
, provided no
information used in equals
comparisons on the
objects is modified.
x
,
x.equals(null)
should return false
.
The equals
method for class Object
implements
the most discriminating possible equivalence relation on objects;
that is, for any non-null reference values x
and
y
, this method returns true
if and only
if x
and y
refer to the same object
(x == y
has the value true
).
Note that it is generally necessary to override the hashCode
method whenever this method is overridden, so as to maintain the
general contract for the hashCode
method, which states
that equal objects must have equal hash codes.
equals
in class Object
obj
- the reference object with which to compare.true
if this object is the same as the obj
argument; false
otherwise.Object.hashCode()
,
HashMap
public int hashCode()
java.lang.Object
HashMap
.
The general contract of hashCode
is:
hashCode
method
must consistently return the same integer, provided no information
used in equals
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.
equals(Object)
method, then calling the hashCode
method on each of
the two objects must produce the same integer result.
Object.equals(java.lang.Object)
method, then calling the hashCode
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. (This is typically implemented by converting the internal
address of the object into an integer, but this implementation
technique is not required by the
JavaTM programming language.)
hashCode
in class Object
Object.equals(java.lang.Object)
,
System.identityHashCode(java.lang.Object)
public String toString()
java.lang.Object
toString
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 class Object
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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