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#Null pointer exception gprojector how to

You just need to run program in debugging mode with debugging toggle points and you can check how variables are declared/initialized/modified. This is the best way to find culprit reference variable. You can easily track reference variable which is reason behind exception.Įclipse is a very smart IDE and it gives you line number where NullPointerException occurred. You have taken so many precautions to avoid NullPointerException but still you got sometimes. What to do if NullPointerException occurs?

You can learn about more ways of avoiding NullPointerException here.

This method returns true if the provided reference is null otherwise returns false.

To check if any reference variable is null or not, we can use isNull() method of Objects class.

When we declare a reference variable, we must verify that object is not null, before we request a method or a field from the objects.

To avoid the NullPointerException, we must ensure that all the objects are initialized properly, before you use them.

So it is programmer responsibility to avoid this exception.

Since it is unchecked exception, it can not be caught by java compiler during compilation. NullPointerException is an unchecked exception which extends RuntimeException.It is because of wrong programming practice. So , NullPointerException is not selenium/Java problem. multiple method calls in a single statement I can list out some more reasons of NullPointerException from here:ġ) Invoking methods on an object which is not initializedĢ) Parameters passed in a method are nullģ) Calling toString() method on object which is nullĤ) Comparing object properties in if block without checking null equalityĥ) Incorrect configuration for frameworks like spring which works on dependency injectionĦ) Using synchronized on an object which is nullħ) Chained statements i.e. Throwing null as if it were a Throwable value.Īpplications should throw instances of this class to indicate other illegal uses of the null object.Accessing or modifying the slots of null as if it were an array.Taking the length of null as if it were an array.Accessing or modifying the field of a null object.Calling the instance method of a null object.NullPointerException is thrown when an application attempts to use null in a case where an object is required.

When we call print method on it, we got NullPointerException. And we just declared np2 and did not initialized it. We perfectly declared and initialized np1 and called print method on it. It means reference variable is pointing to nothing.Īnd when we want to perform any action on such reference variable, we get NullPointerException. When a reference variable is not initialized, it points to NULL. Suppose Demo is a class and we create an object of class Demo as below:Ībove, I just declared a reference variable/object of Class Demo. When we declare a reference variable, internally a pointer is created to reference variable.

#Null pointer exception gprojector how to

So, in this post, we will see what is reason behind above exception and how to solve it. I am correctly using selenium concepts but unable to resolve it.” “I am getting NullPointerException in automation script.