Answers for "how to check if object exists in model class"

javascript check if object property exists

var person = {'first_name': 'bill','age':20};

if ( person.hasOwnProperty('first_name') ) {
    //person has a first_name property
}

java check if property exists in class

public boolean doesObjectContainField(Object object, String fieldName) {
    return Arrays.stream(object.getClass().getFields())
            .anyMatch(f -> f.getName().equals(fieldName));
}