@Test
public void checkThatOtherMethodsAreNonStatic() throws NoSuchMethodException {
Method spin = Earth.class.getDeclaredMethod("spin");
assertFalse("Method spin() should not be static", Modifier.isStatic(spin.getModifiers()));
Method warmUp = Earth.class.getDeclaredMethod("warmUp");
assertFalse("Method warmUp() should not be static", Modifier.isStatic(warmUp.getModifiers()));
}
@Test
public void checkEarthIsAbstract() throws NoSuchMethodException {
assertTrue("Earth class should be abstract", Modifier.isAbstract(Earth.class.getModifiers()));
assertTrue(
"Earth class spin() method should be abstract",
Modifier.isAbstract(Earth.class.getMethod("spin").getModifiers()));
assertTrue(
"Earth class warmUp() method should be abstract",
Modifier.isAbstract(Earth.class.getMethod("warmUp").getModifiers()));
}
@Test
public void checkThatSingletonContainsStaticPrivateInstanceField() {
Field field = findSingletonStaticPrivateInstanceField();
assertNotNull("No static private instance field found.", field);
assertTrue(
"Field pointing to the Earth instance should be static",
Modifier.isStatic(field.getModifiers()));
assertTrue(
"Field pointing to the Earth instance should be private",
Modifier.isPrivate(field.getModifiers()));
}
@Test
public void checkThatConstructorIsProtected() {
for (Constructor<?> constr : Earth.class.getDeclaredConstructors()) {
assertTrue(
"Constructors should be protected to allow subclasses of singleton",
Modifier.isProtected(constr.getModifiers()));
}
}
private Method checkThatSingletonContainsStaticInstanceAccessorMethod(Class clazz) {
for (Method method : clazz.getDeclaredMethods()) {
if (method.getReturnType() == clazz && method.getParameterTypes().length == 0) {
assertTrue(
"Method returning the Earth instance should be static",
Modifier.isStatic(method.getModifiers()));
return method;
}
}
fail("No static accessor method found.");
return null; // will never be called.
}