private void validateClass(Class<?> source, ValidationProblemCollector problems) {
int modifiers = source.getModifiers();
if (Modifier.isInterface(modifiers)) {
problems.add("Must be a class, not an interface");
}
if (source.getEnclosingClass() != null) {
if (Modifier.isStatic(modifiers)) {
if (Modifier.isPrivate(modifiers)) {
problems.add("Class cannot be private");
}
} else {
problems.add("Enclosed classes must be static and non private");
}
}
Constructor<?>[] constructors = source.getDeclaredConstructors();
for (Constructor<?> constructor : constructors) {
if (constructor.getParameterTypes().length > 0) {
problems.add("Cannot declare a constructor that takes arguments");
break;
}
}
Field[] fields = source.getDeclaredFields();
for (Field field : fields) {
int fieldModifiers = field.getModifiers();
if (!field.isSynthetic()
&& !(Modifier.isStatic(fieldModifiers) && Modifier.isFinal(fieldModifiers))) {
problems.add(field, "Fields must be static final.");
}
}
}
/**
* Checks if a class fulfills the JavaBeans contract.
*
* @param cls the class to check
*/
public static void checkJavaBean(Class<?> cls) {
try {
Constructor<?> constructor = cls.getDeclaredConstructor();
int classModifiers = cls.getModifiers();
if (Modifier.isInterface(classModifiers))
throw new RuntimeException(cls.getName() + " is an interface");
if (Modifier.isAbstract(classModifiers))
throw new RuntimeException(
cls.getName() + " cannot be instantiated - it is an abstract class");
int modifiers = constructor.getModifiers();
if (!Modifier.isPublic(modifiers))
throw new RuntimeException("No public default constructor in " + cls);
} catch (NoSuchMethodException e) {
throw new RuntimeException("No default constructor in class " + cls);
} catch (SecurityException e) {
logger.error(
"I am not allowed to check the class by using reflection, "
+ "so I just can hope the class is alright and go on: ",
e);
}
}