The analyzer has detected a parent-class constructor that uses a method overridden in the derived class. As a result, the overridden method can be used by uninitialized class fields.
This behavior occurs when you fail to follow the class initialization procedure stated in JLS [12.5].
Consider the following example:
public class Parent { private String parentStr = "Black"; public Parent () { printInfo(); } public void printInfo () { System.out.println("Parent::printInfo"); System.out.println("parentStr: " + parentStr); System.out.println("-----------------"); } .... } public class Child extends Parent { private int childInt; private String childStr; public Child() { super(); this.childInt = 25; this.childStr = "White"; } public void printInfo () { super.printInfo(); System.out.println("Child::printInfo"); System.out.println("childInt: "+childInt+";childStr: "+childStr); System.out.println("-----------------"); } .... }
If we execute the following line:
Child obj = new Child();
the program will print:
Parent::printInfo parentStr: Black ----------------- Child::printInfo childInt: 0 ; childStr: null -----------------
As seen from this fragment, the overridden method 'printInfo' was called in the parent-class constructor of the 'Parent' class, while the derived 'Child' class was not fully initialized – hence the default values, rather than user-specified values, of the 'childInt' and 'childStr' fields.
The conclusion is this: make sure your parent-class constructors do not use methods that could be overridden in child classes. And if you do use a class method in a constructor, declare it final or private.
This diagnostic is classified as:
|
You can look at examples of errors detected by the V6052 diagnostic. |