How to solve java.lang.NullPointerException error?

The java.lang.NullPointerException error is thrown when an application attempts to use an object reference that has the null value. This usually occurs when you try to call a method or access a field of an object that is null, or when you try to access an element of an array that is null.

To fix a NullPointerException error, you need to identify the source of the null value and make sure that the object is not null before you try to use it. Here are some common causes of the NullPointerException error and how to fix them:

• You are trying to use an object that has not been initialized: Make sure that the object is initialized before you try to use it.

• You are trying to use an object that has been initialized to null: Make sure that the object is not null before you try to use it.

• You are trying to access an element of an array that is null: Make sure that the array is not null before you try to access its elements.

• You are trying to access a field or call a method of an object that is null: Make sure that the object is not null before you try to access its fields or call its methods.

To debug a NullPointerException error, you can use the stack trace of the exception to find out where the error occurred