The problem with invoking Thread.start() in a constructor is that you’ll have a confusing mess on your hands if the class is ever
extended because the superclass' constructor will start the thread before the child class has truly been initialized.
This rule raises an issue any time start is invoked in the constructor of a non-final class.
Noncompliant code example
public class MyClass {
Thread thread = null;
public MyClass(Runnable runnable) {
thread = new Thread(runnable);
thread.start(); // Noncompliant
}
}
