public ArtifactResolutionResult resolve()

in compat/maven-compat/src/main/java/org/apache/maven/artifact/resolver/DefaultArtifactResolver.java [369:524]
115 lines of code
27 McCabe index (conditional complexity)

    public ArtifactResolutionResult resolve(ArtifactResolutionRequest request) {
        Artifact rootArtifact = request.getArtifact();
        Set<Artifact> artifacts = request.getArtifactDependencies();
        Map<String, Artifact> managedVersions = request.getManagedVersionMap();
        List<ResolutionListener> listeners = request.getListeners();
        ArtifactFilter collectionFilter = request.getCollectionFilter();
        ArtifactFilter resolutionFilter = request.getResolutionFilter();
        RepositorySystemSession session = getSession(request.getLocalRepository());

        // TODO: hack because metadata isn't generated in m2e correctly and i want to run the maven i have in the
        // workspace
        if (source == null) {
            try {
                source = container.lookup(ArtifactMetadataSource.class);
            } catch (ComponentLookupException e) {
                // won't happen
            }
        }

        if (listeners == null) {
            listeners = new ArrayList<>();

            if (logger.isDebugEnabled()) {
                listeners.add(new DebugResolutionListener(logger));
            }

            listeners.add(new WarningResolutionListener(logger));
        }

        ArtifactResolutionResult result = new ArtifactResolutionResult();

        // The root artifact may, or may not be resolved so we need to check before we attempt to resolve.
        // This is often an artifact like a POM that is taken from disk and we already have hold of the
        // file reference. But this may be a Maven Plugin that we need to resolve from a remote repository
        // as well as its dependencies.

        if (request.isResolveRoot() /* && rootArtifact.getFile() == null */) {
            try {
                resolve(rootArtifact, request.getRemoteRepositories(), session);
            } catch (ArtifactResolutionException e) {
                result.addErrorArtifactException(e);
                return result;
            } catch (ArtifactNotFoundException e) {
                result.addMissingArtifact(request.getArtifact());
                return result;
            }
        }

        ArtifactResolutionRequest collectionRequest = request;

        if (request.isResolveTransitively()) {
            MetadataResolutionRequest metadataRequest = new DefaultMetadataResolutionRequest(request);

            metadataRequest.setArtifact(rootArtifact);
            metadataRequest.setResolveManagedVersions(managedVersions == null);

            try {
                ResolutionGroup resolutionGroup = source.retrieve(metadataRequest);

                if (managedVersions == null) {
                    managedVersions = resolutionGroup.getManagedVersions();
                }

                Set<Artifact> directArtifacts = resolutionGroup.getArtifacts();

                if (artifacts == null || artifacts.isEmpty()) {
                    artifacts = directArtifacts;
                } else {
                    List<Artifact> allArtifacts = new ArrayList<>();
                    allArtifacts.addAll(artifacts);
                    allArtifacts.addAll(directArtifacts);

                    Map<String, Artifact> mergedArtifacts = new LinkedHashMap<>();
                    for (Artifact artifact : allArtifacts) {
                        String conflictId = artifact.getDependencyConflictId();
                        if (!mergedArtifacts.containsKey(conflictId)) {
                            mergedArtifacts.put(conflictId, artifact);
                        }
                    }

                    artifacts = new LinkedHashSet<>(mergedArtifacts.values());
                }

                collectionRequest = new ArtifactResolutionRequest(request);
                collectionRequest.setServers(request.getServers());
                collectionRequest.setMirrors(request.getMirrors());
                collectionRequest.setProxies(request.getProxies());
                collectionRequest.setRemoteRepositories(resolutionGroup.getResolutionRepositories());
            } catch (ArtifactMetadataRetrievalException e) {
                ArtifactResolutionException are = new ArtifactResolutionException(
                        "Unable to get dependency information for " + rootArtifact.getId() + ": " + e.getMessage(),
                        rootArtifact,
                        metadataRequest.getRemoteRepositories(),
                        e);
                result.addMetadataResolutionException(are);
                return result;
            }
        }

        if (artifacts == null || artifacts.isEmpty()) {
            if (request.isResolveRoot()) {
                result.addArtifact(rootArtifact);
            }
            return result;
        }

        // After the collection we will have the artifact object in the result but they will not be resolved yet.
        result = artifactCollector.collect(
                artifacts, rootArtifact, managedVersions, collectionRequest, source, collectionFilter, listeners, null);

        // We have metadata retrieval problems, or there are cycles that have been detected
        // so we give this back to the calling code and let them deal with this information
        // appropriately.

        if (result.hasMetadataResolutionExceptions()
                || result.hasVersionRangeViolations()
                || result.hasCircularDependencyExceptions()) {
            return result;
        }

        if (result.getArtifactResolutionNodes() != null) {
            ClassLoader classLoader = Thread.currentThread().getContextClassLoader();

            CountDownLatch latch =
                    new CountDownLatch(result.getArtifactResolutionNodes().size());

            for (ResolutionNode node : result.getArtifactResolutionNodes()) {
                Artifact artifact = node.getArtifact();

                if (resolutionFilter == null || resolutionFilter.include(artifact)) {
                    executor.execute(new ResolveTask(
                            classLoader, latch, artifact, session, node.getRemoteRepositories(), result));
                } else {
                    latch.countDown();
                }
            }
            try {
                latch.await();
            } catch (InterruptedException e) {
                result.addErrorArtifactException(
                        new ArtifactResolutionException("Resolution interrupted", rootArtifact, e));
            }
        }

        // We want to send the root artifact back in the result but we need to do this after the other dependencies
        // have been resolved.
        if (request.isResolveRoot()) {
            // Add the root artifact (as the first artifact to retain logical order of class path!)
            Set<Artifact> allArtifacts = new LinkedHashSet<>();
            allArtifacts.add(rootArtifact);
            allArtifacts.addAll(result.getArtifacts());
            result.setArtifacts(allArtifacts);
        }

        return result;
    }