[php] How can I solve "Non-static method xxx:xxx() should not be called statically in PHP 5.4?

Disabling the alert message is not a way to solve the problem. Despite the PHP core is continue to work it makes a dangerous assumptions and actions.

Never ignore the error where PHP should make an assumptions of something!!!!

If the class organized as a singleton you can always use function getInstance() and then use getData()

Likse:

$classObj = MyClass::getInstance();
$classObj->getData();

If the class is not a singleton, use

 $classObj = new MyClass();
 $classObj->getData();