Vfrdtyky

I have a java, spring web application using maven as build mechanism. Consider the following code (over-simplified version of my situation) where a controller calls a service to perform some operation and it turn calls some DAO methods to perform some actions in DB.

class MyController extends Controller {

    public ModelAndView handleRequest(... request) {

        boolean performCheck = Boolean.valueOf(request.getParameter("doCheck"));

        myService.doSomeAction(object)

        return ...; 

    } 

}



class MyService {

    public void doSomeAction(Object o){

        myDao.doSomething(o);

    }

}



class MyDao exterds HibernateDaoSuppot {

    boolean check;



    public void doSomething(Object o){

        if(check == true){

            // some action

        } else {

            // some other action

        }



    }

}

My question is how can I alter the value of the check boolean in the Dao method, based on the value I receive in the controller without explicitly passing the boolean through all the layers? I work with a legacy code with lot of business logics and the business team is not confident of making too many modifications to the existing code. However I am free to add any no of classes or aspects to perform the same.

I have tried reading the call stack in the DAO method and determine the boolean several layers above, but I do not feel good about working with the call stack and I am afraid that some future changes in the app architecture or JVM changes can mess up the call stack.

Of course the best is to pass the boolean variable. but instead; you can declare two functions, one for perfromCheck == true and another one for performCheck == false and call either from the controller based on the value of performCheck.

You can add a transient(transient only if object is a persistent object) boolean field in your object.

Set the value of the boolean in your controller before passing the object to your service.
You wont even need to maintain a separate check variable in your DAO layer.

Your controller might look like:

class MyController extends Controller {

    public ModelAndView handleRequest(... request) {

        object.setPerform(Boolean.valueOf(request.getParameter("doCheck"))); // object has a boolean field named 'perform'

        myService.doSomeAction(object)

        return ...; 

    } 

}

Your MyDao might look like:

class MyDao exterds HibernateDaoSuppot {

    //boolean check; wont need this



    public void doSomething(Object o){

        if(o.getPerform() == true){

            // some action

        } else {

            // some other action

        }

    }

}

As your case: "check" is property of MyDao, you want change it dynamically from a method scope, this may cause Concurrent issues if you use single instance, that's not recommend.

As mentioned by above user, you can use two MyDao instance in your app, one declare with True and the other with False, and your controller determine which one to use.

You could make the boolean in the controller as a private class attribute and then use a getter to access its value from Dao.