org.pf.reflect
Class ClassInfo

java.lang.Object
  org.pf.reflect.ClassInfo

public class ClassInfo
extends java.lang.Object

Contains the name of a class and the class itself. It can create new instances.

Version:

1.2

Author:

Manfred Duchrow

Field Summary

static java.lang.Object[]

EMPTY_OBJECT_ARRAY

Constructor Summary

ClassInfo(java.lang.Class aClass)
Initialize the new instance with a class.

ClassInfo(java.lang.Class aClass, boolean singleton)
Initialize the new instance with a class.

ClassInfo(java.lang.String className)
Initialize the new instance with a class name.

ClassInfo(java.lang.String className, boolean singleton)
Initialize the new instance with a class name and a flag if it is a singleton.

Method Summary

java.lang.Object	createInstance() Returns a new instance of the class or null in any case of error.
java.lang.String	getClassName() Returns the name of the class, this object represents.
java.lang.Class	getClassObject() Returns the the class object.
java.lang.Object	getInstance() Returns either a new instance of the underlying class or always the identical instance if it is defined to be a singleton.
boolean	isAssignableFrom(java.lang.Class type) Determines if the class or interface represented by this ClassInfo object is either the same as, or is a superclass or superinterface of, the class or interface represented by the specified Class parameter.
boolean	isAssignableTo(java.lang.Class type) Determines if the class or interface represented by the specified class parameter is either the same as, or is a superclass or superinterface of, the class or interface represented by this ClassInfo object.
boolean	isInstance(java.lang.Object object) Determines if the specified Object is assignment-compatible with the object represented by this ClassInfo.
boolean	isSingleton()
java.lang.Object[]	newArray(int size) Returns a new array of the type represented by this ClassInfo.
java.lang.Object	newInstance() Returns a new instance of the class.
void	setClassName(java.lang.String className) Set the name of the class this object should represent.
void	setClassObject(java.lang.Class aClass) Set the class object.
void	setIsSingleton(boolean newValue)
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

EMPTY_OBJECT_ARRAY

public static final java.lang.Object[] EMPTY_OBJECT_ARRAY

Constructor Detail

ClassInfo

public ClassInfo(java.lang.String className)

Initialize the new instance with a class name.

Parameters:

className - The name of the class the new object should represent.

ClassInfo

public ClassInfo(java.lang.String className,
                 boolean singleton)

Initialize the new instance with a class name and a flag if it is a singleton.

Parameters:

className - The name of the class the new object should represent.

singleton - if true method getInstance() will return always the identical instance

ClassInfo

public ClassInfo(java.lang.Class aClass)

Initialize the new instance with a class.

Parameters:

aClass - The class the new object should represent.

ClassInfo

public ClassInfo(java.lang.Class aClass,
                 boolean singleton)

Initialize the new instance with a class.

Parameters:

aClass - The class the new object should represent.

singleton - if true method getInstance() will return always the identical instance

Method Detail

isSingleton

public boolean isSingleton()

setIsSingleton

public void setIsSingleton(boolean newValue)

isAssignableFrom

public boolean isAssignableFrom(java.lang.Class type)

Determines if the class or interface represented by this ClassInfo object is either the same as, or is a superclass or superinterface of, the class or interface represented by the specified Class parameter. It returns true if so; otherwise it returns false. If this ClassInfo object represents a primitive type, this method returns true if the specified Class parameter is exactly this Class object; otherwise it returns false.

Parameters:

type - the Class object to be checked

isAssignableTo

public boolean isAssignableTo(java.lang.Class type)

Determines if the class or interface represented by the specified class parameter is either the same as, or is a superclass or superinterface of, the class or interface represented by this ClassInfo object. It returns true if so; otherwise it returns false. If specified class parameter is a primitive type, this method returns true if this ClassInfo object rerpresents exactly the same Class object; otherwise it returns false.

Parameters:

type - the Class object to be checked

isInstance

public boolean isInstance(java.lang.Object object)

Determines if the specified Object is assignment-compatible with the object represented by this ClassInfo. This method is the dynamic equivalent of the Java language instanceof operator. The method returns true if the specified Object argument is non-null and can be cast to the reference type represented by this ClassInfo object without raising a ClassCastException. It returns false otherwise.

Parameters:

object - the object to check

getClassName

public java.lang.String getClassName()

Returns the name of the class, this object represents.

setClassName

public void setClassName(java.lang.String className)

Set the name of the class this object should represent. Additionally the corresponding class object is set to null.

Parameters:

className - A fully qualified class name

getClassObject

public java.lang.Class getClassObject()

Returns the the class object. If the class can't be found by the class loader, null will be returned.

setClassObject

public void setClassObject(java.lang.Class aClass)

Set the class object. The name will be set automatically to the given class's name.

Parameters:

aClass - A class

getInstance

public java.lang.Object getInstance()

Returns either a new instance of the underlying class or always the identical instance if it is defined to be a singleton.

Returns:

An instance of the underlying class

See Also:

isSingleton(), setIsSingleton(boolean)

createInstance

public java.lang.Object createInstance()

Returns a new instance of the class or null in any case of error. If more detailed information about a failed instance creation is necessary, the better method is newInstance.

See Also:

newInstance()

newInstance

public java.lang.Object newInstance()
                             throws java.lang.ClassNotFoundException,
                                    java.lang.InstantiationException,
                                    java.lang.IllegalAccessException

Returns a new instance of the class.

Throws:

java.lang.ClassNotFoundException - If the class represented by this object can't be found

java.lang.InstantiationException - If no none-argument constructor is available/visible

java.lang.IllegalAccessException - If for security reasons the instance creation of this class prohibited

See Also:

createInstance()

newArray

public java.lang.Object[] newArray(int size)

Returns a new array of the type represented by this ClassInfo. Returns Object[0] if this ClassInfo does not represent a valid and loadable class.

Parameters:

size - The number of elements the new array whould have (must not be negative)

Returns:

the new array

Throws:

java.lang.NullPointerException - if the specified componentType parameter is null

java.lang.IllegalArgumentException - if componentType is Void.TYPE

java.lang.NegativeArraySizeException - if the specified length is negative

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

See Also:

Object.toString()