No Argument Constructor Example

In this section you will learn how to know that whether any class consists No-Argument Constructor or not ?. Here is an example that provides the usage of the newInstance() method in more detail.

No Argument Constructor Example

In this section you will learn how to know that whether any class consists No-Argument Constructor or not ?. Here is an example that provides the usage of the newInstance() method in more detail.

No Argument Constructor Example

No Argument Constructor Example

     

In this section you will learn how to know that whether any class consists No-Argument Constructor or not ?. Here is an example that provides the usage of the newInstance() method in more detail.

Here in our example we have used "forName()" static method of Class and then we have invoked newInstance() method to create a new object without any argument. Invoking newInstance() method throws a NoSuchMethodException if the class does not have any no-argument constructor.

Here is code for example:

 

 

 

NoArgConstructor.java

import java.lang.reflect.*;
import java.util.ArrayList;

public class NoArgConstructor {
  public static void main(String str[]){
  try{
 ArrayList list = (ArrayList)
   (Class.forName("java.util.ArrayList").newInstance());
 System.out.println("No-Argument Constructor exist.");
 System.out.println("New Object created Successfully");
  }catch(Exception e){
  System.out.println("No-argument constructor does not exist.");
  System.out.println(e.getMessage());
  }
 }
}

Output:

Download Source code

Tutorials

  1. Reflection API Tutorials and Examples
  2. Getting the implemented Interfaces
  3. Retrieving the class name through Reflection API
  4. Finding out the super class name of the class
  5. Getting the method name used in the Application
  6. Reflection API Tutorials and Examples
  7. Finding out the object of the class
  8. Finding out the class fields
  9. Getting information about Constructor
  10. No Argument Constructor Example
  11. Getting Methods Information of a class
  12. Identifying array using Reflection
  13. Getting Fields Information of a class
  14. Getting Component type
  15. Examine Interface Example
  16. Class Modifier Example
  17. Calling ( Invoking ) Methods through Reflection
  18. Setting Fields Information of a class using Reflection
  19. Reflection API : A Brief Introduction
  20. Reflection In Java
  21. How to Invoke method using Reflection API of Java?