Java Language Tutorial => Call constructor of nested class

Example

If you want to create an instance of an inner nested class you need to provide a class object of the enclosing class as an extra parameter with Class#getDeclaredConstructor.

public class Enclosing{
    public class Nested{
    public Nested(String a){
            System.out.println("Constructor :String => "+a);
        }
    }       
    public static void main(String args[]) throws Exception {
        Class<?> clazzEnclosing = Class.forName("Enclosing");            
        Class<?> clazzNested = Class.forName("Enclosing$Nested");
        Enclosing objEnclosing = (Enclosing)clazzEnclosing.newInstance();
        Constructor<?> constructor = clazzNested.getDeclaredConstructor(new Class[]{Enclosing.class, String.class});
        Nested objInner = (Nested)constructor.newInstance(new Object[]{objEnclosing, "StackOverFlow"});
    }
}

If the nested class is static you will not need this enclosing instance.

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