Test class that detects how the strictfp modifier is propagated in different scenarios. The test is based on Java Reflection API

StrictfpReflectionTest.java

import java.lang.reflect.Modifier;

strictfp interface StrictInterface {

    void someInterfaceMethod();

    default void someInterfaceDefaultMethod() {}

    class InnerTest {
        public static void innerMethod() {}
    }
}

class Impl implements StrictInterface {
    @Override
    public void someInterfaceMethod() {}

    public strictfp void someClassMethod() {}

    public void someClassMethod2() {}
}

public class StrictfpReflectionTest {
    public static void main(String argv[]) {
        //The comments next to checkModifiers method call are showing the output on jdk1.8.0_91 on OSX
        checkModifiers(Impl.class, "someInterfaceMethod");  // someInterfaceMethod modifiers: public
        checkModifiers(Impl.class, "someClassMethod"); // someClassMethod modifiers: public strictfp
        checkModifiers(Impl.class, "someClassMethod2"); // someClassMethod2 modifiers: public

        checkModifiers(Impl.class.getInterfaces()[0], "someInterfaceDefaultMethod"); // someInterfaceDefaultMethod modifiers: public strictfp
        checkModifiers(StrictInterface.InnerTest.class, "innerMethod"); // innerMethod modifiers: public static strictfp
    }
    public static void checkModifiers(Class clazz, String m) {
        try {
            int mod = clazz.getDeclaredMethod(m, new Class[0]).getModifiers();
            String res = m + " modifiers: " + Modifier.toString(mod);
            System.out.println(res);
        } catch (Exception e) {
            e.printStackTrace(System.out);
        }
    }
}