If you need to create an object with the no-argument constructor, you can invoke the
The following sample program creates an instance of the
newInstance
method upon a Class
object. The newInstance
method throws a NoSuchMethodException
if the class does not have a no-argument constructor. For more information on working with Constructor
objects, see Discovering Class Constructors. The following sample program creates an instance of the
Rectangle
class using the no-argument constructor by calling the newInstance
method: The output of the preceding program is:import java.lang.reflect.*; import java.awt.*; class SampleNoArg { public static void main(String[] args) { Rectangle r = (Rectangle) createObject("java.awt.Rectangle"); System.out.println(r.toString()); } static Object createObject(String className) { Object object = null; try { Class classDefinition = Class.forName(className); object = classDefinition.newInstance(); } catch (InstantiationException e) { System.out.println(e); } catch (IllegalAccessException e) { System.out.println(e); } catch (ClassNotFoundException e) { System.out.println(e); } return object; } }
java.awt.Rectangle[x=0,y=0,width=0,height=0]
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