Class’s non-default constructor is not getting called

I was trying to implement the DriverScript-class as mentioned in the below-link, but, it seems that the non-default DriverScript()-constructor is not getting called. As a result all the codes (shown below) are not getting executed. That's why I’m getting a “NullPointerException” whenever referring the “method” (of type Method[]) variable afterwards in the class.

public DriverScript() throws NoSuchMethodException, SecurityException {
        actionKeywords = new ActionKeywords();
        method = actionKeywords.getClass().getMethods();
}

Reference Link: http://toolsqa.com/selenium-webdriver/keyword-driven-framework/set-up-java-constant-variables/

Here is my DriverScript.class for reference:

package executionEngine;

import java.lang.reflect.Method;
import config.ActionKeywords;
import utility.ExcelUtils;

public class DriverScript {

    public static ActionKeywords actKeyObj;
    public static String stepActionKey;
    public static Method method[];

    public DriverScript() throws NoSuchMethodException, SecurityException {
        actKeyObj = new ActionKeywords();
            method = actKeyObj.getClass().getMethods();
    //System.out.println(“Hello”);
    }

    public static void main(String[] args) throws Exception {
        String spreadSheetPath = “C:\\Users\\demo\\Desktop\\Workspace\\Mydemo2\\src\\dataEngine\\DataEngine.xlsx”;
        ExcelUtils.setExcelFile(spreadSheetPath, “Test Steps”);
        for(int row=1; row<9; row++) {
            stepActionKey = ExcelUtils.getCellData(row, 3);
            //System.out.println(stepActionKey);
            execute_Step();
        }
    }

    private static void execute_Step() throws Exception {
        //System.out.println(method.length);
        for(int i=0; i<method.length; i++) {
            if(method[i].getName().equals(stepActionKey)) {
                method[i].invoke(actKeyObj);
                break;
            }
        }
    }
}

Please help/suggest me on this issue.