If your class relies on too many others, it will be coupled and fragile. A long import list is a good indicator.
TL;DR: Don't import too much.
Problems
Coupling
Single Responsibility Principle violation
Low Cohesion
Solutions
Break the class
Hide intermediate accidental implementation
Sample Code
Wrong
import java.util.LinkedList;
import java.persistence;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
import java.util.NoSuchElementException
import java.util.Queue;
import org.fermi.common.util.ClassUtil;
import org.fermi.Data;
//We rely on too many libraries
public class Demo {
public static void main(String[] args) {
}
}
Right
import org.fermi.domainModel;
import org.fermi.workflow;
//We rely on few libraries
//and we hide their implementation
//So maybe transitive imports are the same
//but we don't break encapsulation
public class Demo {
public static void main(String[] args) {
}
}
Detection
We can set a warning threshold on our linters.
Tags
Coupling
Ripple Effect
Conclusion
We need to think about dependencies when building our solutions to minimize Ripple Effect.
Relations
More Info
Credits
Photo by Zdeněk Macháček on Unsplash
An indicator of a class that does too many things - so, that goes against SRP - is the number of imported namespaces.
If there are too many referenced namespaces ("using" directives in C#), it means that your class is doing too many things at once.
The fewer, the better!18:02 PM - 11 Oct 2021
Fools ignore complexity. Pragmatists suffer it. Some can avoid it. Geniuses remove it.
Alan Perlis
This article is part of the CodeSmell Series.
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