java.lang.reflect
Class Constructor<T>

java.lang.Object
  java.lang.reflect.AccessibleObject
      java.lang.reflect.Constructor<T>

All Implemented Interfaces:

AnnotatedElement, GenericDeclaration, Member

public final class Constructor<T>
extends AccessibleObject
implements GenericDeclaration, Member

This class models a constructor. Information about the constructor can be accessed, and the constructor can be invoked dynamically.

Field Summary

(package private) Class<T>	declaringClass
(package private) Class<?>[]	exceptionTypes
(package private) TypeVariable<Constructor<T>>[]	formalTypeParameters
(package private) org.apache.harmony.luni.lang.reflect.ListOfTypes	genericExceptionTypes
(package private) org.apache.harmony.luni.lang.reflect.ListOfTypes	genericParameterTypes
(package private) Class<?>[]	parameterTypes
(package private) int	slot

Fields inherited from class java.lang.reflect.AccessibleObject

flag, trans

Fields inherited from interface java.lang.reflect.Member

DECLARED, PUBLIC

Method Summary

boolean	equals(Object object) Compares the specified object to this Constructor and answer if they are equal.
Annotation[]	getDeclaredAnnotations() Gets all Annotations that are explicitly declared by this element (not inherited).
Class<T>	getDeclaringClass() Return the Class associated with the class that defined this constructor.
Class<?>[]	getExceptionTypes() Return an array of the Class objects associated with the exceptions declared to be thrown by this constructor.
Type[]	getGenericExceptionTypes() Gets the exception types as an array of Type instances.
Type[]	getGenericParameterTypes() Gets the parameter types as an array of Type instances, in declaration order.
int	getModifiers() Return the modifiers for the modeled constructor.
String	getName() Return the name of the modeled constructor.
Annotation[][]	getParameterAnnotations() Gets an array of arrays that represent the annotations of the formal parameters of this constructor.
Class<?>[]	getParameterTypes() Return an array of the Class objects associated with the parameter types of this constructor.
(package private) String	getSignatureAttribute() Gets the Signature attribute for this instance.
TypeVariable<Constructor<T>>[]	getTypeParameters() Returns an array of generic type variables used in this constructor.
int	hashCode() Returns an integer hash code for the receiver.
boolean	isSynthetic() Indicates whether or not this constructor is synthetic.
boolean	isVarArgs() Indicates whether or not this constructor takes a variable number argument.
T	newInstance(Object... args) Return a new instance of the declaring class, initialized by dynamically invoking the modeled constructor.
String	toGenericString() Returns the String representation of the constructor's declaration, including the type parameters.
String	toString() Returns a string containing a concise, human-readable description of the receiver.

Methods inherited from class java.lang.reflect.AccessibleObject

appendArrayGenericType, appendArrayType, appendArrayType, appendGenericType, appendSimpleType, getAnnotation, getAnnotations, getClassSignatureAttribute, getReflectionAccess, getSignature, isAccessible, isAnnotationPresent, setAccessible, setAccessible, setAccessibleNoCheck, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

declaringClass

Class<T> declaringClass

parameterTypes

Class<?>[] parameterTypes

exceptionTypes

Class<?>[] exceptionTypes

genericExceptionTypes

org.apache.harmony.luni.lang.reflect.ListOfTypes genericExceptionTypes

genericParameterTypes

org.apache.harmony.luni.lang.reflect.ListOfTypes genericParameterTypes

formalTypeParameters

TypeVariable<Constructor<T>>[] formalTypeParameters

slot

int slot

Method Detail

getSignatureAttribute

String getSignatureAttribute()

Gets the Signature attribute for this instance. Returns null if not found.

Overrides:

getSignatureAttribute in class AccessibleObject

getTypeParameters

public TypeVariable<Constructor<T>>[] getTypeParameters()

Returns an array of generic type variables used in this constructor.

Specified by:

getTypeParameters in interface GenericDeclaration

Returns:

The array of type parameters.

toGenericString

public String toGenericString()

Returns the String representation of the constructor's declaration, including the type parameters.

Returns:

An instance of String.

Since:

1.5

getGenericParameterTypes

public Type[] getGenericParameterTypes()

Gets the parameter types as an array of Type instances, in declaration order. If the constructor has no parameters, then an empty array is returned.

Returns:

An array of Type instances.

Throws:

GenericSignatureFormatError - if the generic method signature is invalid.

TypeNotPresentException - if the component type points to a missing type.

MalformedParameterizedTypeException - if the component type points to a type that can't be instantiated for some reason.

Since:

1.5

getGenericExceptionTypes

public Type[] getGenericExceptionTypes()

Gets the exception types as an array of Type instances. If the constructor has no declared exceptions, then an empty array is returned.

Returns:

An array of Type instances.

Throws:

GenericSignatureFormatError - if the generic method signature is invalid.

TypeNotPresentException - if the component type points to a missing type.

MalformedParameterizedTypeException - if the component type points to a type that can't be instantiated for some reason.

Since:

1.5

getDeclaredAnnotations

public Annotation[] getDeclaredAnnotations()

Description copied from interface: AnnotatedElement

Gets all Annotations that are explicitly declared by this element (not inherited).

Specified by:

getDeclaredAnnotations in interface AnnotatedElement

Overrides:

getDeclaredAnnotations in class AccessibleObject

Returns:

An array of Annotations, which may be empty, but never null.

getParameterAnnotations

public Annotation[][] getParameterAnnotations()

Gets an array of arrays that represent the annotations of the formal parameters of this constructor. If there are no parameters on this constructor, then an empty array is returned. If there are no annotations set, then and array of empty arrays is returned.

Returns:

An array of arrays of Annotation instances.

Since:

1.5

isVarArgs

public boolean isVarArgs()

Indicates whether or not this constructor takes a variable number argument.

Returns:

A value of true if a vararg is declare, otherwise false.

Since:

1.5

isSynthetic

public boolean isSynthetic()

Indicates whether or not this constructor is synthetic.

Specified by:

isSynthetic in interface Member

Returns:

A value of true if it is synthetic, or false otherwise.

Since:

1.5

equals

public boolean equals(Object object)

Compares the specified object to this Constructor and answer if they are equal. The object must be an instance of Constructor with the same defining class and parameter types.

Overrides:

equals in class Object

Parameters:

object - the object to compare

Returns:

true if the specified object is equal to this Constructor, false otherwise

See Also:

hashCode()

getDeclaringClass

public Class<T> getDeclaringClass()

Return the Class associated with the class that defined this constructor.

Specified by:

getDeclaringClass in interface Member

Returns:

the declaring class

getExceptionTypes

public Class<?>[] getExceptionTypes()

Return an array of the Class objects associated with the exceptions declared to be thrown by this constructor. If the constructor was not declared to throw any exceptions, the array returned will be empty.

Returns:

the declared exception classes

getModifiers

public int getModifiers()

Return the modifiers for the modeled constructor. The Modifier class should be used to decode the result.

Specified by:

getModifiers in interface Member

Returns:

the modifiers

See Also:

Modifier

getName

public String getName()

Return the name of the modeled constructor. This is the name of the declaring class.

Specified by:

getName in interface Member

Returns:

the name

getParameterTypes

public Class<?>[] getParameterTypes()

Return an array of the Class objects associated with the parameter types of this constructor. If the constructor was declared with no parameters, the array returned will be empty.

Returns:

the parameter types

hashCode

public int hashCode()

Returns an integer hash code for the receiver. Objects which are equal answer the same value for this method. The hash code for a Constructor is the hash code of the declaring class' name.

Overrides:

hashCode in class Object

Returns:

the receiver's hash

See Also:

equals(java.lang.Object)

newInstance

public T newInstance(Object... args)
              throws InstantiationException,
                     IllegalAccessException,
                     IllegalArgumentException,
                     InvocationTargetException

Return a new instance of the declaring class, initialized by dynamically invoking the modeled constructor. This reproduces the effect of new declaringClass(arg1, arg2, ... , argN) This method performs the following:

• A new instance of the declaring class is created. If the declaring class cannot be instantiated (i.e. abstract class, an interface, an array type, or a base type) then an InstantiationException is thrown.
• If this Constructor object is enforcing access control (see AccessibleObject) and the modeled constructor is not accessible from the current context, an IllegalAccessException is thrown.
• If the number of arguments passed and the number of parameters do not match, an IllegalArgumentException is thrown.
• For each argument passed:
  • If the corresponding parameter type is a base type, the argument is unwrapped. If the unwrapping fails, an IllegalArgumentException is thrown.
  • If the resulting argument cannot be converted to the parameter type via a widening conversion, an IllegalArgumentException is thrown.
• The modeled constructor is then invoked. If an exception is thrown during the invocation, it is caught and wrapped in an InvocationTargetException. This exception is then thrown. If the invocation completes normally, the newly initialized object is returned.

Parameters:

args - the arguments to the constructor

Returns:

the new, initialized, object

Throws:

InstantiationException - if the class cannot be instantiated

IllegalAccessException - if the modeled constructor is not accessible

IllegalArgumentException - if an incorrect number of arguments are passed, or an argument could not be converted by a widening conversion

InvocationTargetException - if an exception was thrown by the invoked constructor

See Also:

AccessibleObject

toString

public String toString()

Returns a string containing a concise, human-readable description of the receiver. The format of the string is modifiers (if any) declaring class name '(' parameter types, separated by ',' ')' If the constructor throws exceptions, ' throws ' exception types, separated by ',' For example: public String(byte[],String) throws UnsupportedEncodingException

Overrides:

toString in class Object

Returns:

a printable representation for the receiver