WildcardImport
Wildcard imports, static or otherwise, should not be used

Category
Severity
SUGGESTION
Maturity

The problem

Wildcard imports are forbidden by §3.3.1 of the Google Java Style Guide.

They make code brittle and difficult to reason about, both for programmers and for tools. In the following example, the processing of the first import requires reasoning about the classes Outer and Nested, including their supertypes, and ends up depending on information in the second import statement. This code is (incorrectly) rejected by the latest version of javac. Also, note that I is actually being imported via the name p.q.C.I even though it’s not declared in C! Its canonical name is p.q.D.I. Regular single-type imports require that all types are imported by their canonical name, but static imports do not.

package p;

import static p.Outer.Nested.*;
import static p.q.C.*;

public class Outer {
  public static class Nested implements I {
  }
}
package p.q;

public class C extends D {
}
package p.q;

public class D {
  public interface I {
  }
}