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JavaTM 2 Platform Standard Edition |
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SUMMARY: INNER | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Object | +--java.lang.reflect.AccessibleObject | +--java.lang.reflect.Constructor
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 an
IllegalArgumentException
if a narrowing conversion would occur.
Member
,
Class
,
Class.getConstructors()
,
java.lang.Class#getConstructor()
,
Class.getDeclaredConstructors()
Fields inherited from interface java.lang.reflect.Member |
DECLARED,
PUBLIC |
Method Summary | |
boolean |
equals(Object obj)
Compares this Constructor against the specified object. |
Class |
getDeclaringClass()
Returns the Class object representing the class that declares
the constructor represented by this Constructor object. |
Class[] |
getExceptionTypes()
Returns an array of Class objects that represent the types of
of exceptions declared to be thrown by the underlying constructor
represented by this Constructor object. |
int |
getModifiers()
Returns the Java language modifiers for the constructor represented by this Constructor object, as an integer. |
String |
getName()
Returns the name of this constructor, as a string. |
Class[] |
getParameterTypes()
Returns an array of Class objects that represent the formal
parameter types, in declaration order, of the constructor
represented by this Constructor object. |
int |
hashCode()
Returns a hashcode for this Constructor . |
Object |
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. |
String |
toString()
Returns a string describing this Constructor . |
Methods inherited from class java.lang.reflect.AccessibleObject |
isAccessible,
setAccessible,
setAccessible |
Methods inherited from class java.lang.Object |
clone,
finalize,
getClass,
notify,
notifyAll,
wait,
wait,
wait |
Method Detail |
public Class getDeclaringClass()
Class
object representing the class that declares
the constructor represented by this Constructor
object.public String getName()
public int getModifiers()
Constructor
object, as an integer. The
Modifier
class should be used to decode the modifiers.Modifier
public Class[] getParameterTypes()
Class
objects that represent the formal
parameter types, in declaration order, of the constructor
represented by this Constructor
object. Returns an array of
length 0 if the underlying constructor takes no parameters.public Class[] getExceptionTypes()
Class
objects that represent the types of
of exceptions declared to be thrown by the underlying constructor
represented by this Constructor
object. Returns an array of
length 0 if the constructor declares no exceptions in its throws
clause.public boolean equals(Object obj)
Constructor
against the specified object.
Returns true if the objects are the same. Two Constructor
objects are
the same if they were declared by the same class and have the
same formal parameter types.obj
- the reference object with which to compare.true
if this object is the same as the obj
argument; false
otherwise.Boolean.hashCode()
,
Hashtable
public int hashCode()
Constructor
. The hashcode is
the same as the hashcode for the underlying constructor's
declaring class name.Object.equals(java.lang.Object)
,
Hashtable
public String toString()
Constructor
. 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)
The only possible modifiers for constructors are the access modifiers public, protected or private. Only one of these may appear, or none if the constructor has default (package) access.
public Object newInstance(Object[] initargs) throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException
Constructor
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.
Returns the newly created and initialized object.
Creation proceeds with the following steps, in order:
If the class that declares the underlying constructor
represents an abstract class, the creation throws an
InstantiationException
.
If this Constructor
object enforces Java language access
control and the underlying constructor is inaccessible, the
creation throws an IllegalAccessException
.
If the number of actual parameters supplied via initargs
is
different from the number of formal parameters required by the
underlying constructor, the creation throws an
IllegalArgumentException
.
A new instance of the constructor's declaring class is created, and its fields are initialized to their default initial values.
For each actual parameter in the supplied initargs
array:
If the corresponding formal parameter has a primitive type,
an unwrapping conversion is attempted to convert the object
value to a value of the primitive type. If this attempt fails,
the creation throws an IllegalArgumentException
.
If, after possible unwrapping, the parameter value cannot be
converted to the corresponding formal parameter type by a
method invocation conversion, the creation throws an
IllegalArgumentException
.
The constructor's declaring class is initialized if it has not already been initialized. A new instance of the constructor's declaring class is created, and its fields are initialized to their default initial values.
Control transfers to the underlying constructor to
initialize the new instance. If the constructor completes
abruptly by throwing an exception, the exception is placed in
an InvocationTargetException
and thrown in turn to the caller
of newInstance
.
If the constructor completes normally, returns the newly created and initialized instance.
|
JavaTM 2 Platform Standard Edition |
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PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
SUMMARY: INNER | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |