* The dot separator is not included in the returned string.
     *
     * @return the file extension or an empty string if none, never {@code null}
     */
    @Nonnull
    String getExtension();

    /**
     * {@return a unique string identifying this artifact}.
     *
     * The default implementation returns a colon-separated list of group

public interface ArtifactCoordinatesFactoryRequest extends Request<Session> {

    String getGroupId();

    String getArtifactId();

    String getVersion();

    String getClassifier();

    String getExtension();

    String getType();

    String getCoordinatesString();

    @Nonnull
    static ArtifactCoordinatesFactoryRequest build(

                || ("jar".equals(artifact.getExtension()) && "tests".equals(artifact.getClassifier()));
    }

    private File findInProjectLocalRepository(Artifact artifact) {
        // Prefer the consumer POM when resolving POMs from the project-local repository,
        // to avoid treating a build POM as a repository (consumer) POM.
        if ("pom".equals(artifact.getExtension())) {

            return classifier;
        } else {
            return artifact.getClassifier();
        }
    }

    @Override
    public String getExtension() {
        if (extension != null) {
            return extension;
        } else {
            return artifact.getExtension();
        }
    }

    @Override
    public String getVersion() {
        if (version != null) {
            return version;

                .artifactId(coordinates.getArtifactId())
                .version(coordinates.getVersionConstraint().toString())
                .classifier(coordinates.getClassifier())
                .extension(coordinates.getExtension())
                .build();
    }

    @Nonnull
    static DependencyCoordinatesFactoryRequest build(@Nonnull Session session, @Nonnull Dependency dependency) {
        return builder()

    }

    /**
     * @throws Exception
     */
    public void testGetExtension() throws Exception {
        assertEquals("1", "xml", ResourceUtil.getExtension("aaa/bbb.xml"));
        assertEquals("2", null, ResourceUtil.getExtension("aaa"));
    }

    /**
     * @throws Exception
     */
    public void testRemoteExtension() throws Exception {

        assertFalse(depArtifact.isSnapshot(), "Expected " + depArtifact + ".isSnapshot() to return false");
        assertEquals("", depArtifact.getClassifier());
        assertEquals("jar", depArtifact.getExtension());
        assertEquals("java", depArtifact.getProperty("language", null));
        assertEquals("jar", depArtifact.getProperty("type", null));
        assertEquals("true", depArtifact.getProperty("constitutesBuildPath", null));

                        result.addException(exception);
                    }
                }
            } else {
                String key = SNAPSHOT + getKey(artifact.getClassifier(), artifact.getExtension());
                merge(infos, SNAPSHOT, key);
                if (!resolve(result, infos, key)) {
                    result.setVersion(version);
                }
            }

@Immutable
public interface ArtifactFactoryRequest extends Request<Session> {

    String getGroupId();

    String getArtifactId();

    String getVersion();

    String getClassifier();

    String getExtension();

    String getType();

    static ArtifactFactoryRequest build(
            Session session, String groupId, String artifactId, String version, String extension) {
        return ArtifactFactoryRequest.builder()

        when(artifact.getGroupId()).thenReturn("group1");
        when(artifact.getArtifactId()).thenReturn("artifact1");
        when(artifact.getExtension()).thenReturn("ext");
        when(artifact.getClassifier()).thenReturn("classifier1");
        when(artifact.getVersion()).thenReturn("1");
        artifacts.add(artifact);