It’s not my code! I googled it.

1 minute read

Actually this blog post is not about Google. And it is even not about copying code. But it is indeed about code which I did not write.

Since a couple days we use SonarQube to check our code for coding style or conventions violations. Well this is not that new. We used to use Checkstyle, PMD, Findbugs already for a couple of years. But the switch to Sonar brought the heap of violations in our code up my mind again. Sonar says we have around 3000-5000 violations in our projects. Probably the most of them are eligible. But some of them are not:

equals fail

Here you see some of the violations found in the Configuration class in the equals() method. Nearly each line has a violation. The problem is: equals() is a automatically generated method. Coding conventions violations in generated code are just useless. Generated code doesn’t has to be maintainable. It doesn’t has to be readable.

I thought about how to tell Sonar to ignore this code. One could use the //NOSONAR comment to make Sonar ignore lines. But you’d have to place it on every line. Or you could use


but this would suppress all warnings, not only Sonar violations (reference).

Then I stumbled upon @Generated annotation which is part of Java since 1.6. Using this annotation, code generators could automatically mark generated code, making life easier for code analyzers and developers. So in a perfect world my Eclipse code generator would generate this method:

@Generated("Eclipse source generator")
public boolean equals(final Object obj) {
    if (this == obj) return true;
    if (obj == null) return false;
    if (getClass() != obj.getClass()) return false;
    final ConfigurationBase other = (ConfigurationBase) obj;
    if (autoRefreshDatabaseEnabled != other.autoRefreshDatabaseEnabled) return false;

and all code analyzers would magically ignore this method.

This idea was already picked up by the sonar team. But sadly it’s not yet implemented.

Update: The issue is fixed now. @Generated methods are ignored since SonarQube Java plugin 4.9.