Category: pmd
Rule Key: pmd:AccessorClassGeneration
Instantiation by way of private constructors from outside of the constructor’s class often causes the generation of an accessor. A factory method, or non-privatization of the constructor can eliminate this situation. The generated class file is actually an interface. It gives the accessing class the ability to invoke a new hidden package scope constructor that takes the interface as a supplementary parameter. This turns a private constructor effectively into one with package scope, and is challenging to discern.
public class Outer {
void method() {
Inner ic = new Inner(); // Causes generation of accessor class
}
public class Inner {
private Inner() {}
}
}