Should one define a variable with new() in a class or should one inject it
Hi,
I have a class :
public class AuthenticationManager {
private static final Logger _logger = LoggerFactory.getTrimmer(A
private final List<Listener> _listeners = new ArrayList<Listener>();
private boolean _verificationInProgress = false;
private final CallStateReceiver callStateReceiver = new CallStateReceiver();
I was wondering is it a good practice to have the line :
private final CallStateReceiver callStateReceiver = new CallStateReceiver();
or should one chnage it to private final CallStateReceiver callStateReceiver ; and get it set from outside ?
What way can we define this ?
Thanks
I have a class :
public class AuthenticationManager {
private static final Logger _logger = LoggerFactory.getTrimmer(A
private final List<Listener> _listeners = new ArrayList<Listener>();
private boolean _verificationInProgress = false;
private final CallStateReceiver callStateReceiver = new CallStateReceiver();
I was wondering is it a good practice to have the line :
private final CallStateReceiver callStateReceiver = new CallStateReceiver();
or should one chnage it to private final CallStateReceiver callStateReceiver ; and get it set from outside ?
What way can we define this ?
Thanks
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ASKER
HI,
I did not understand the point -
Consider a case in future if you have another flavor of CallStateReceiver (say MyCallStateReceiver) and you want to use it in place of CallStateReceiver. How will you do it ? It is not possible
MyCallStateReceiver will also have the object inside it.. how is it not possible. please clarify exactly what you mean.
thanks
I did not understand the point -
Consider a case in future if you have another flavor of CallStateReceiver (say MyCallStateReceiver) and you want to use it in place of CallStateReceiver. How will you do it ? It is not possible
MyCallStateReceiver will also have the object inside it.. how is it not possible. please clarify exactly what you mean.
thanks
ASKER
Hi,
Can you please give an example of :
Even better, you might define an interface that lays out the minimum criteria that your class expects from an object.
Can you please give an example of :
Even better, you might define an interface that lays out the minimum criteria that your class expects from an object.
If you instantiate the object inside the class, your code is tightly coupled and dependent on the objects created using new(). Best approach is, as suggested by kaufmed, to provide the objects from outside.
Consider a case in future if you have another flavor of CallStateReceiver (say MyCallStateReceiver) and you want to use it in place of CallStateReceiver. How will you do it ? It is not possible if you instantiate the object inside the class, you will need to have mechanism (ie. setter or constructor) where objects can be provided outside the class.
Hope the explains.