Movatterモバイル変換

Class Constructor<T>

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

Type Parameters:
T - the class in which the constructor is declared
All Implemented Interfaces:
AnnotatedElement,GenericDeclaration,Member
```
public final classConstructor<T>extendsExecutable
```
Constructor provides information about, and access to, a single constructor for a class.
Constructor permits widening conversions to occur when matching the actual parameters to newInstance() with the underlying constructor's formal parameters, but throws anIllegalArgumentException if a narrowing conversion would occur.
Since:
1.1
See Also:
Member,Class,Class.getConstructors(),Class.getConstructor(Class[]),Class.getDeclaredConstructors()

Field Summary
- Fields declared in interface java.lang.reflect.Member
  DECLARED,PUBLIC

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`equals(Object obj)`	Compares this`Constructor` against the specified object.
`AnnotatedType`	`getAnnotatedReceiverType()`	Returns an`AnnotatedType` object that represents the use of a type to specify the receiver type of the method/constructor represented by this`Executable` object.
`AnnotatedType`	`getAnnotatedReturnType()`	Returns an`AnnotatedType` object that represents the use of a type to specify the return type of the method/constructor represented by this Executable.
`<T extendsAnnotation> T`	`getAnnotation(Class<T> annotationClass)`	Returns this element's annotation for the specified type if such an annotation ispresent, else null.
`Annotation[]`	`getDeclaredAnnotations()`	Returns annotations that aredirectly present on this element.
`Class<T>`	`getDeclaringClass()`	Returns the`Class` object representing the class that declares the constructor represented by this object.
`Type[]`	`getGenericExceptionTypes()`	Returns an array of`Type` objects that represent the exceptions declared to be thrown by this executable object.
`Type[]`	`getGenericParameterTypes()`	Returns an array of`Type` objects that represent the formal parameter types, in declaration order, of the executable represented by this object.
`String`	`getName()`	Returns the name of this constructor, as a string.
`Annotation[][]`	`getParameterAnnotations()`	Returns an array of arrays of`Annotation`s that represent the annotations on the formal parameters, in declaration order, of the`Executable` represented by this object.
`int`	`getParameterCount()`	Returns the number of formal parameters (whether explicitly declared or implicitly declared or neither) for the executable represented by this object.
`TypeVariable<Constructor<T>>[]`	`getTypeParameters()`	Returns an array of`TypeVariable` objects that represent the type variables declared by the generic declaration represented by this`GenericDeclaration` object, in declaration order.
`int`	`hashCode()`	Returns a hashcode for this`Constructor`.
`boolean`	`isSynthetic()`	Returns`true` if this executable is a synthetic construct; returns`false` otherwise.
`boolean`	`isVarArgs()`	Returns`true` if this executable was declared to take a variable number of arguments; returns`false` otherwise.
`T`	`newInstance(Object... initargs)`	Uses the constructor represented by this`Constructor` object to create and initialize a new instance of the constructor's declaring class, with the specified initialization parameters.
`void`	`setAccessible(boolean flag)`	Set the`accessible` flag for this reflected object to the indicated boolean value.
`String`	`toGenericString()`	Returns a string describing this`Constructor`, including type parameters.
`String`	`toString()`	Returns a string describing this`Constructor`.

Methods declared in class java.lang.reflect.Executable
getAnnotatedExceptionTypes,getAnnotatedParameterTypes,getAnnotationsByType,getExceptionTypes,getModifiers,getParameters,getParameterTypes

Methods declared in class java.lang.reflect.AccessibleObject
canAccess,getAnnotations,getDeclaredAnnotation,getDeclaredAnnotationsByType,isAccessible,isAnnotationPresent,setAccessible,trySetAccessible

Methods declared in class java.lang.Object
clone,finalize,getClass,notify,notifyAll,wait,wait,wait

Methods declared in interface java.lang.reflect.AnnotatedElement
getAnnotations,getDeclaredAnnotation,getDeclaredAnnotationsByType,isAnnotationPresent

- Method Detail
  - setAccessible
```
public void setAccessible(boolean flag)
```
    Set theaccessible flag for this reflected object to the indicated boolean value. A value oftrue indicates that the reflected object should suppress checks for Java language access control when it is used. A value offalse indicates that the reflected object should enforce checks for Java language access control when it is used, with the variation noted in the class description.
    This method may be used by a caller in classC to enable access to amember ofdeclaring classD if any of the following hold:
    C andD are in the same module.
    The member ispublic andD ispublic in a package that the module containingDexports to at least the module containingC.
    The member isprotectedstatic,D ispublic in a package that the module containingD exports to at least the module containingC, andC is a subclass ofD.
    D is in a package that the module containingDopens to at least the module containingC. All packages in unnamed and open modules are open to all modules and so this method always succeeds whenD is in an unnamed or open module.
    This method cannot be used to enable access to private members, members with default (package) access, protected instance members, or protected constructors when the declaring class is in a different module to the caller and the package containing the declaring class is not open to the caller's module.
    If there is a security manager, itscheckPermission method is first called with aReflectPermission("suppressAccessChecks") permission.
    ASecurityException is also thrown if this object is aConstructor object for the classClass andflag is true.
    Overrides:
    setAccessible in class AccessibleObject
    Parameters:
    flag - the new value for theaccessible flag
    Throws:
    InaccessibleObjectException - if access cannot be enabled
    SecurityException - if the request is denied by the security manager or this is a constructor forjava.lang.Class
    See Also:
    AccessibleObject.trySetAccessible(),MethodHandles.privateLookupIn(java.lang.Class<?>, java.lang.invoke.MethodHandles.Lookup)
  - getDeclaringClass
```
public Class<T> getDeclaringClass()
```
    Returns theClass object representing the class that declares the constructor represented by this object.
    Specified by:
    getDeclaringClass in interface Member
    Specified by:
    getDeclaringClass in class Executable
    Returns:
    an object representing the declaring class of the underlying member
  - getName
```
public String getName()
```
    Returns the name of this constructor, as a string. This is the binary name of the constructor's declaring class.
    Specified by:
    getName in interface Member
    Specified by:
    getName in class Executable
    Returns:
    the simple name of the underlying member
  - getTypeParameters
```
public TypeVariable<Constructor<T>>[] getTypeParameters()
```
    Returns an array ofTypeVariable objects that represent the type variables declared by the generic declaration represented by thisGenericDeclaration object, in declaration order. Returns an array of length 0 if the underlying generic declaration declares no type variables.
    Specified by:
    getTypeParameters in interface GenericDeclaration
    Specified by:
    getTypeParameters in class Executable
    Returns:
    an array ofTypeVariable objects that represent the type variables declared by this generic declaration
    Throws:
    GenericSignatureFormatError - if the generic signature of this generic declaration does not conform to the format specified inThe Java™ Virtual Machine Specification
    Since:
    1.5
  - getParameterCount
```
public int getParameterCount()
```
    Returns the number of formal parameters (whether explicitly declared or implicitly declared or neither) for the executable represented by this object.
    Overrides:
    getParameterCount in class Executable
    Returns:
    The number of formal parameters for the executable this object represents
    Since:
    1.8
  - getGenericParameterTypes
```
public Type[] getGenericParameterTypes()
```
    Returns an array ofType objects that represent the formal parameter types, in declaration order, of the executable represented by this object. Returns an array of length 0 if the underlying executable takes no parameters.
    If a formal parameter type is a parameterized type, theType object returned for it must accurately reflect the actual type parameters used in the source code.
    If a formal parameter type is a type variable or a parameterized type, it is created. Otherwise, it is resolved.
    Overrides:
    getGenericParameterTypes in class Executable
    Returns:
    an array ofTypes that represent the formal parameter types of the underlying executable, in declaration order
    Throws:
    GenericSignatureFormatError - if the generic method signature does not conform to the format specified inThe Java™ Virtual Machine Specification
    TypeNotPresentException - if any of the parameter types of the underlying executable refers to a non-existent type declaration
    MalformedParameterizedTypeException - if any of the underlying executable's parameter types refer to a parameterized type that cannot be instantiated for any reason
    Since:
    1.5
  - getGenericExceptionTypes
```
public Type[] getGenericExceptionTypes()
```
    Returns an array ofType objects that represent the exceptions declared to be thrown by this executable object. Returns an array of length 0 if the underlying executable declares no exceptions in itsthrows clause.
    If an exception type is a type variable or a parameterized type, it is created. Otherwise, it is resolved.
    Overrides:
    getGenericExceptionTypes in class Executable
    Returns:
    an array of Types that represent the exception types thrown by the underlying executable
    Throws:
    GenericSignatureFormatError - if the generic method signature does not conform to the format specified inThe Java™ Virtual Machine Specification
    TypeNotPresentException - if the underlying executable'sthrows clause refers to a non-existent type declaration
    MalformedParameterizedTypeException - if the underlying executable'sthrows clause refers to a parameterized type that cannot be instantiated for any reason
    Since:
    1.5
  - equals
```
public boolean equals(Object obj)
```
    Compares thisConstructor against the specified object. Returns true if the objects are the same. TwoConstructor objects are the same if they were declared by the same class and have the same formal parameter types.
    Overrides:
    equals in class Object
    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
  - hashCode
```
public int hashCode()
```
    Returns a hashcode for thisConstructor. The hashcode is the same as the hashcode for the underlying constructor's declaring class name.
    Overrides:
    hashCode in class Object
    Returns:
    a hash code value for this object.
    See Also:
    Object.equals(java.lang.Object),System.identityHashCode(java.lang.Object)
  - toString
```
public String toString()
```
    Returns a string describing thisConstructor. The string is formatted as the constructor access modifiers, if any, followed by the fully-qualified name of the declaring class, followed by a parenthesized, comma-separated list of the constructor's formal parameter types. For example:
    public java.util.Hashtable(int,float)
    If the constructor is declared to throw exceptions, the parameter list is followed by a space, followed by the word "throws" followed by a comma-separated list of the thrown exception types.
    The only possible modifiers for constructors are the access modifierspublic,protected orprivate. Only one of these may appear, or none if the constructor has default (package) access.
    Overrides:
    toString in class Object
    Returns:
    a string describing thisConstructor
    SeeThe Java™ Language Specification:
    8.8.3 Constructor Modifiers, 8.9.2 Enum Body Declarations
  - toGenericString
```
public String toGenericString()
```
    Returns a string describing thisConstructor, including type parameters. The string is formatted as the constructor access modifiers, if any, followed by an angle-bracketed comma separated list of the constructor's type parameters, if any, followed by the fully-qualified name of the declaring class, followed by a parenthesized, comma-separated list of the constructor's generic formal parameter types. If this constructor was declared to take a variable number of arguments, instead of denoting the last parameter as "Type[]", it is denoted as "Type...". A space is used to separate access modifiers from one another and from the type parameters or class name. If there are no type parameters, the type parameter list is elided; if the type parameter list is present, a space separates the list from the class name. If the constructor is declared to throw exceptions, the parameter list is followed by a space, followed by the word "throws" followed by a comma-separated list of the generic thrown exception types.
    The only possible modifiers for constructors are the access modifierspublic,protected orprivate. Only one of these may appear, or none if the constructor has default (package) access.
    Specified by:
    toGenericString in class Executable
    Returns:
    a string describing thisConstructor, include type parameters
    Since:
    1.5
    SeeThe Java™ Language Specification:
    8.8.3 Constructor Modifiers, 8.9.2 Enum Body Declarations
  - newInstance
```
public T newInstance(Object... initargs)              throwsInstantiationException,IllegalAccessException,IllegalArgumentException,InvocationTargetException
```
    Uses the constructor represented by thisConstructor object to create and initialize a new instance of the constructor's declaring class, with the specified initialization parameters. Individual parameters are automatically unwrapped to match primitive formal parameters, and both primitive and reference parameters are subject to method invocation conversions as necessary.
    If the number of formal parameters required by the underlying constructor is 0, the suppliedinitargs array may be of length 0 or null.
    If the constructor's declaring class is an inner class in a non-static context, the first argument to the constructor needs to be the enclosing instance; see section 15.9.3 ofThe Java™ Language Specification.
    If the required access and argument checks succeed and the instantiation will proceed, the constructor's declaring class is initialized if it has not already been initialized.
    If the constructor completes normally, returns the newly created and initialized instance.
    Parameters:
    initargs - array of objects to be passed as arguments to the constructor call; values of primitive types are wrapped in a wrapper object of the appropriate type (e.g. afloat in aFloat)
    Returns:
    a new object created by calling the constructor this object represents
    Throws:
    IllegalAccessException - if thisConstructor object is enforcing Java language access control and the underlying 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; if this constructor pertains to an enum type.
    InstantiationException - if the class that declares the underlying constructor represents an abstract class.
    InvocationTargetException - if the underlying constructor throws an exception.
    ExceptionInInitializerError - if the initialization provoked by this method fails.
  - isVarArgs
```
public boolean isVarArgs()
```
    Returnstrue if this executable was declared to take a variable number of arguments; returnsfalse otherwise.
    Overrides:
    isVarArgs in class Executable
    Returns:
    true if an only if this executable was declared to take a variable number of arguments.
    Since:
    1.5
  - isSynthetic
```
public boolean isSynthetic()
```
    Returnstrue if this executable is a synthetic construct; returnsfalse otherwise.
    Specified by:
    isSynthetic in interface Member
    Overrides:
    isSynthetic in class Executable
    Returns:
    true if and only if this executable is a synthetic construct as defined byThe Java™ Language Specification.
    Since:
    1.5
    SeeThe Java™ Language Specification:
    13.1 The Form of a Binary
  - getAnnotation
```
public <T extendsAnnotation> T getAnnotation(Class<T> annotationClass)
```
    Returns this element's annotation for the specified type if such an annotation ispresent, else null.
    Specified by:
    getAnnotation in interface AnnotatedElement
    Overrides:
    getAnnotation in class Executable
    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
    Since:
    1.5
  - getDeclaredAnnotations
```
public Annotation[] getDeclaredAnnotations()
```
    Returns annotations that aredirectly present on this element. This method ignores inherited annotations. If there are no annotationsdirectly 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 interface AnnotatedElement
    Overrides:
    getDeclaredAnnotations in class AccessibleObject
    Returns:
    annotations directly present on this element
    Since:
    1.5
  - getParameterAnnotations
```
public Annotation[][] getParameterAnnotations()
```
    Returns an array of arrays ofAnnotations that represent the annotations on the formal parameters, in declaration order, of theExecutable represented by this object. Synthetic and mandated parameters (see explanation below), such as the outer "this" parameter to an inner class constructor will be represented in the returned array. If the executable has no parameters (meaning no formal, no synthetic, and no mandated parameters), a zero-length array will be returned. If theExecutable has one or more parameters, a nested array of length zero is returned for each parameter with no annotations. The annotation objects contained in the returned arrays are serializable. The caller of this method is free to modify the returned arrays; it will have no effect on the arrays returned to other callers. A compiler may add extra parameters that are implicitly declared in source ("mandated"), as well as parameters that are neither implicitly nor explicitly declared in source ("synthetic") to the parameter list for a method. SeeParameter for more information.
    Specified by:
    getParameterAnnotations in class Executable
    Returns:
    an array of arrays that represent the annotations on the formal and implicit parameters, in declaration order, of the executable represented by this object
    Since:
    1.5
    See Also:
    Parameter,AnnotatedElement.getAnnotations()
  - getAnnotatedReturnType
```
public AnnotatedType getAnnotatedReturnType()
```
    Returns anAnnotatedType object that represents the use of a type to specify the return type of the method/constructor represented by this Executable. If thisExecutable object represents a constructor, the AnnotatedType object represents the type of the constructed object. If thisExecutable object represents a method, the AnnotatedType object represents the use of a type to specify the return type of the method.
    Specified by:
    getAnnotatedReturnType in class Executable
    Returns:
    an object representing the return type of the method or constructor represented by thisExecutable
    Since:
    1.8
  - getAnnotatedReceiverType
```
public AnnotatedType getAnnotatedReceiverType()
```
    Returns anAnnotatedType object that represents the use of a type to specify the receiver type of the method/constructor represented by thisExecutable object. The receiver type of a method/constructor is available only if the method/constructor has a receiver parameter (JLS 8.4.1). If this Executable objectrepresents an instance method or represents a constructor of an inner member class, and the method/constructoreither has no receiver parameter or has a receiver parameter with no annotations on its type, then the return value is anAnnotatedType object representing an element with no annotations. If thisExecutable object represents a static method or represents a constructor of a top level, static member, local, or anonymous class, then the return value is null.
    Overrides:
    getAnnotatedReceiverType in class Executable
    Returns:
    an object representing the receiver type of the method or constructor represented by thisExecutable ornull if thisExecutable can not have a receiver parameter
    Since:
    1.8

Movatterモバイル変換

Class Constructor<T>

Field Summary

Fields declared in interface java.lang.reflect.Member

Method Summary

Methods declared in class java.lang.reflect.Executable

Methods declared in class java.lang.reflect.AccessibleObject

Methods declared in class java.lang.Object

Methods declared in interface java.lang.reflect.AnnotatedElement

Method Detail

setAccessible

getDeclaringClass

getName

getTypeParameters

getParameterCount

getGenericParameterTypes

getGenericExceptionTypes

equals

hashCode

toString

toGenericString

newInstance

isVarArgs

isSynthetic

getAnnotation

getDeclaredAnnotations

getParameterAnnotations

getAnnotatedReturnType

getAnnotatedReceiverType