Magic number sonar violation on JPA annotations

Question

We are using sonar for managing our code quality. I have a problem with "Magic Number" violation for JPA annotation like that:

@NotNull
@Size(min = 1, max = 300)
@Column(name = "NAME")

Is this a true violation for annotation?

If not, how can we deal this kind of Sonar violation?

Answer 1

The Magic Number violation doesn't understand if this number appears in an annotation or not. IMHO this is a false-positive and you can deal with it in two ways. Either disable this rule in your quality profile or create a MAGICNUMBER class and list all the numbers you're using as static properties. For example look the following class

public final class MAGICNUMBER {
public static final int L8000 = 8000;
public static final int L300 = 300;

}

Then you can use it in your class like this

@NotNull
@Size(min = 1, max = MAGICNUMBER.L300)
@Column(name = "NAME")

Answer 2

I'm not sure how it was in 2012, but finding this now, there appears to be a way to disable it just for annotations in v 3.3.2, and surely above that

Answer 3

You can edit the rule in your checkstyle file so it doesn't take into account annotation, hashcode methods or specific numbers.

<module name="MagicNumber">
    <property name="ignoreNumbers" value="-1, 0, 1, 2, 3"/>
    <property name="ignoreHashCodeMethod" value="true" />
    <property name="ignoreAnnotation" value="true" />
</module>