public void execute()

in src/main/java/org/apache/maven/plugins/assembly/mojos/AbstractAssemblyMojo.java [452:553]
85 lines of code
23 McCabe index (conditional complexity)

    public void execute() throws MojoExecutionException, MojoFailureException {

        if (skipAssembly) {
            getLog().info("Assemblies have been skipped per configuration of the skipAssembly parameter.");
            return;
        }

        // run only at the execution root.
        if (runOnlyAtExecutionRoot && !isThisTheExecutionRoot()) {
            getLog().info("Skipping the assembly in this project because it's not the Execution Root");
            return;
        }

        List<Assembly> assemblies;
        try {
            assemblies = assemblyReader.readAssemblies(this);
        } catch (final AssemblyReadException e) {
            throw new MojoExecutionException("Error reading assemblies: " + e.getMessage(), e);
        } catch (final InvalidAssemblerConfigurationException e) {
            throw new MojoFailureException(
                    assemblyReader, e.getMessage(), "Mojo configuration is invalid: " + e.getMessage());
        }

        // TODO: include dependencies marked for distribution under certain formats
        // TODO: how, might we plug this into an installer, such as NSIS?

        FileTime outputDate = MavenArchiver.parseBuildOutputTimestamp(outputTimestamp)
                .map(FileTime::from)
                .orElse(null);

        boolean warnedAboutMainProjectArtifact = false;
        for (final Assembly assembly : assemblies) {
            try {
                final String fullName = AssemblyFormatUtils.getDistributionName(assembly, this);

                List<String> effectiveFormats = formats;
                if (effectiveFormats == null || effectiveFormats.isEmpty()) {
                    effectiveFormats = assembly.getFormats();
                }
                if (effectiveFormats == null || effectiveFormats.isEmpty()) {
                    throw new MojoFailureException(
                            "No formats specified in the execution parameters or the assembly descriptor.");
                }

                for (final String format : effectiveFormats) {
                    final File destFile = assemblyArchiver.createArchive(
                            assembly,
                            fullName,
                            format,
                            this,
                            isRecompressZippedFiles(),
                            getMergeManifestMode(),
                            outputDate);

                    final MavenProject project = getProject();
                    final String type = project.getArtifact().getType();

                    if (attach && destFile.isFile()) {
                        if (isAssemblyIdAppended()) {
                            projectHelper.attachArtifact(project, format, assembly.getId(), destFile);
                        } else if (!"pom".equals(type) && format.equals(type)) {
                            if (!warnedAboutMainProjectArtifact) {
                                final StringBuilder message = new StringBuilder();

                                message.append("Configuration option 'appendAssemblyId' is set to false.");
                                message.append("\nInstead of attaching the assembly file: ")
                                        .append(destFile);
                                message.append(", it will become the file for main project artifact.");
                                message.append("\nNOTE: If multiple descriptors or descriptor-formats are provided "
                                        + "for this project, the value of this file will be "
                                        + "non-deterministic!");

                                getLog().warn(message);
                                warnedAboutMainProjectArtifact = true;
                            }

                            final File existingFile = project.getArtifact().getFile();
                            if ((existingFile != null) && existingFile.exists()) {
                                getLog().warn("Replacing pre-existing project main-artifact file: " + existingFile
                                        + "\nwith assembly file: " + destFile);
                            }

                            project.getArtifact().setFile(destFile);
                        } else {
                            projectHelper.attachArtifact(project, format, null, destFile);
                        }
                    } else if (attach) {
                        getLog().warn("Assembly file: " + destFile + " is not a regular file (it may be a directory). "
                                + "It cannot be attached to the project build for installation or "
                                + "deployment.");
                    }
                }
            } catch (final ArchiveCreationException | AssemblyFormattingException e) {
                throw new MojoExecutionException("Failed to create assembly: " + e.getMessage(), e);
            } catch (final InvalidAssemblerConfigurationException e) {
                throw new MojoFailureException(
                        assembly,
                        "Assembly is incorrectly configured: " + assembly.getId(),
                        "Assembly: " + assembly.getId() + " is not configured correctly: " + e.getMessage());
            }
        }
    }