private Model loadPom()

in impl/maven-impl/src/main/java/org/apache/maven/impl/resolver/DefaultArtifactDescriptorReader.java [122:275]


    private Model loadPom(
            RepositorySystemSession session, ArtifactDescriptorRequest request, ArtifactDescriptorResult result)
            throws ArtifactDescriptorException {
        RequestTrace trace = RequestTrace.newChild(request.getTrace(), request);

        LinkedHashSet<String> visited = new LinkedHashSet<>();
        for (Artifact a = request.getArtifact(); ; ) {
            Artifact pomArtifact = ArtifactDescriptorUtils.toPomArtifactUnconditionally(a);
            try {
                VersionRequest versionRequest =
                        new VersionRequest(a, request.getRepositories(), request.getRequestContext());
                versionRequest.setTrace(trace);
                VersionResult versionResult = versionResolver.resolveVersion(session, versionRequest);

                a = a.setVersion(versionResult.getVersion());

                versionRequest =
                        new VersionRequest(pomArtifact, request.getRepositories(), request.getRequestContext());
                versionRequest.setTrace(trace);
                versionResult = versionResolver.resolveVersion(session, versionRequest);

                pomArtifact = pomArtifact.setVersion(versionResult.getVersion());
            } catch (VersionResolutionException e) {
                result.addException(e);
                throw new ArtifactDescriptorException(result);
            }

            if (!visited.add(a.getGroupId() + ':' + a.getArtifactId() + ':' + a.getBaseVersion())) {
                RepositoryException exception =
                        new RepositoryException("Artifact relocations form a cycle: " + visited);
                invalidDescriptor(session, trace, a, exception);
                if ((getPolicy(session, a, request) & ArtifactDescriptorPolicy.IGNORE_INVALID) != 0) {
                    return null;
                }
                result.addException(exception);
                throw new ArtifactDescriptorException(result);
            }

            ArtifactResult resolveResult;
            try {
                ArtifactRequest resolveRequest =
                        new ArtifactRequest(pomArtifact, request.getRepositories(), request.getRequestContext());
                resolveRequest.setTrace(trace);
                resolveResult = artifactResolver.resolveArtifact(session, resolveRequest);
                pomArtifact = resolveResult.getArtifact();
                result.setRepository(resolveResult.getRepository());
            } catch (ArtifactResolutionException e) {
                if (e.getCause() instanceof ArtifactNotFoundException artifactNotFoundException) {
                    missingDescriptor(session, trace, a, artifactNotFoundException);
                    if ((getPolicy(session, a, request) & ArtifactDescriptorPolicy.IGNORE_MISSING) != 0) {
                        return null;
                    }
                }
                result.addException(e);
                throw new ArtifactDescriptorException(result);
            }

            Model model;

            // TODO hack: don't rebuild model if it was already loaded during reactor resolution
            final WorkspaceReader workspace = session.getWorkspaceReader();
            if (workspace instanceof MavenWorkspaceReader mavenWorkspaceReader) {
                model = mavenWorkspaceReader.findModel(pomArtifact);
                if (model != null) {
                    return model;
                }
            }

            try {
                InternalSession iSession = InternalSession.from(session);
                List<RemoteRepository> repositories = request.getRepositories().stream()
                        .map(iSession::getRemoteRepository)
                        .toList();
                String gav =
                        pomArtifact.getGroupId() + ":" + pomArtifact.getArtifactId() + ":" + pomArtifact.getVersion();
                ModelBuilderRequest modelRequest = ModelBuilderRequest.builder()
                        .session(iSession)
                        .trace(RequestTraceHelper.toMaven(request.getRequestContext(), trace))
                        .requestType(ModelBuilderRequest.RequestType.CONSUMER_DEPENDENCY)
                        .source(Sources.resolvedSource(pomArtifact.getPath(), gav))
                        // This merge is on purpose because otherwise user properties would override model
                        // properties in dependencies the user does not know. See MNG-7563 for details.
                        .systemProperties(toProperties(session.getUserProperties(), session.getSystemProperties()))
                        .userProperties(Map.of())
                        .repositoryMerging(ModelBuilderRequest.RepositoryMerging.REQUEST_DOMINANT)
                        .repositories(repositories)
                        .build();

                ModelBuilderResult modelResult = modelBuilder.newSession().build(modelRequest);
                // ModelBuildingEx is thrown only on FATAL and ERROR severities, but we still can have WARNs
                // that may lead to unexpected build failure, log them
                if (modelResult.getProblemCollector().hasWarningProblems()) {
                    ProblemCollector<ModelProblem> problemCollector = modelResult.getProblemCollector();
                    int totalProblems = problemCollector.totalProblemsReported();
                    if (logger.isDebugEnabled()) {
                        StringBuilder sb = new StringBuilder();
                        sb.append(totalProblems)
                                .append(" ")
                                .append((totalProblems == 1) ? "problem was" : "problems were")
                                .append(" encountered while building the effective model for '")
                                .append(request.getArtifact())
                                .append("' during ")
                                .append(RequestTraceHelper.interpretTrace(true, request.getTrace()))
                                .append("\n")
                                .append((totalProblems == 1) ? "Problem" : "Problems");
                        for (ModelProblem modelProblem :
                                problemCollector.problems().toList()) {
                            sb.append("\n* ")
                                    .append(modelProblem.getMessage())
                                    .append(" @ ")
                                    .append(ModelProblemUtils.formatLocation(modelProblem, null));
                        }
                        logger.warn(sb.toString());
                    } else {
                        logger.warn(
                                "{} {} encountered while building the effective model for '{}' during {} (use -X to see details)",
                                totalProblems,
                                (totalProblems == 1) ? "problem was" : "problems were",
                                request.getArtifact(),
                                RequestTraceHelper.interpretTrace(false, request.getTrace()));
                    }
                }
                model = modelResult.getEffectiveModel();
            } catch (ModelBuilderException e) {
                for (ModelProblem problem :
                        e.getResult().getProblemCollector().problems().toList()) {
                    if (problem.getException() instanceof ModelResolverException modelResolverException) {
                        result.addException(modelResolverException);
                        throw new ArtifactDescriptorException(result);
                    }
                }
                invalidDescriptor(session, trace, a, e);
                if ((getPolicy(session, a, request) & ArtifactDescriptorPolicy.IGNORE_INVALID) != 0) {
                    return null;
                }
                result.addException(e);
                throw new ArtifactDescriptorException(result);
            }

            Artifact relocatedArtifact = getRelocation(session, result, model);
            if (relocatedArtifact != null) {
                if (withinSameGav(relocatedArtifact, a)) {
                    result.setArtifact(relocatedArtifact);
                    return model; // they share same model
                } else {
                    result.addRelocation(a);
                    a = relocatedArtifact;
                    result.setArtifact(a);
                }
            } else {
                return model;
            }
        }
    }