PMD Ignore Spring Field Injections in gradle config
Problem Description:
Currently I have several Controllers that inject dependencies through a field marked with @Autowired. When I try to run gradle build the following violations come up.
These all correspond to the instances of where a spring component has been injected.
I am aware of the ignoreAnnotations property that seems to exist for PMD, however, I am not sure if one can actually specify this in a gradle configuration?
Any help would be appreciated.
Solution – 1
The root cause is: field injection is code smell and bad design practice.
When @Autowired is used on a non-transient field it can cause issues with serialization. This is because the field will not be properly initialized when the object is deserialized, leading to a NullPointerException when the object is used.
To fix this issue either make the fields transient or — much better — use constructor injection. To use constructor injection add a constructor to your class that takes all of the required dependencies as arguments, and annotate the constructor with @Autowired (the annotation is optional in modern Spring versions).
@Component
class MyClass {
private final Dependency1 dependency1;
private final Dependency2 dependency2;
@Autowired
public MyClass(Dependency1 dependency1, Dependency2 dependency2) {
this.dependency1 = dependency1;
this.dependency2 = dependency2;
}
}