/**
* Performs a deep comparison (using reflection) of two objects to determine whether they are
* different.
*
* <p>If the object is a Question then the answer is treated specially because the original value
* of the answer from our point of view is the value provided by the client in an Answer fact. If
* no such fact exists then the value on the question itself is used. Scenarios are:
*
* <ul>
* <li>Question which client has just answered - the new object is different if the answer is
* not the value provided by the client. i.e. if the rules have changed it to something else
* e.g. converting text to upper case.
* <li>Another question - the new object is different if the answer is not the value on the
* original object.
* </ul>
*
* @param originalObject
* @param newObject
* @return
*/
private boolean different(TohuObject originalObject, TohuObject newObject) {
if (!originalObject.equals(newObject)) {
return true;
}
// special handling for Question answers
if (originalObject instanceof Question) {
Question originalQuestion = (Question) originalObject;
String originalAnswer;
if (clientAnswers != null && clientAnswers.containsKey(originalQuestion.getId())) {
// original answer is the one provided by the client
originalAnswer = clientAnswers.get(originalQuestion.getId());
} else {
// original answer not provided by client so is contained in the original question
originalAnswer =
originalQuestion.getAnswer() == null ? null : originalQuestion.getAnswer().toString();
}
Question newQuestion = (Question) newObject;
String newAnswer =
newQuestion.getAnswer() == null ? null : newQuestion.getAnswer().toString();
if (originalAnswer == null ? newAnswer != null : !originalAnswer.equals(newAnswer)) {
return true;
}
}
Class<?> clazz = originalObject.getClass();
do {
// compare all non-static non-transient fields
for (Field field : clazz.getDeclaredFields()) {
int modifiers = field.getModifiers();
if (!Modifier.isStatic(modifiers) && !Modifier.isTransient(modifiers)) {
boolean answerField = field.isAnnotationPresent(Question.AnswerField.class);
// answer fields are skipped because we have checked this already
if (!answerField) {
field.setAccessible(true);
try {
Object originalValue = field.get(originalObject);
Object newValue = field.get(newObject);
if (originalValue == null ? newValue != null : !originalValue.equals(newValue)) {
return true;
}
} catch (IllegalArgumentException e) {
throw new RuntimeException(e);
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
}
}
}
}
clazz = clazz.getSuperclass();
} while (clazz != null);
return false;
}
