public void executeMain()

in src/main/org/apache/tools/ant/taskdefs/Zip.java [645:796]
118 lines of code
29 McCabe index (conditional complexity)

    public void executeMain() throws BuildException {

        checkAttributesAndElements();

        // Renamed version of original file, if it exists
        File renamedFile = null;
        addingNewFiles = true;

        processDoUpdate();
        processGroupFilesets();

        // collect filesets to pass them to getResourcesToAdd
        final List<ResourceCollection> vfss = new ArrayList<>();
        if (baseDir != null) {
            final FileSet fs = (FileSet) getImplicitFileSet().clone();
            fs.setDir(baseDir);
            vfss.add(fs);
        }
        vfss.addAll(resources);

        final ResourceCollection[] fss =
            vfss.toArray(new ResourceCollection[0]);

        boolean success = false;
        try {
            // can also handle empty archives
            final ArchiveState state = getResourcesToAdd(fss, zipFile, false);

            // quick exit if the target is up to date
            if (!state.isOutOfDate()) {
                return;
            }

            final File parent = zipFile.getParentFile();
            if (parent != null && !parent.isDirectory()
                && !(parent.mkdirs() || parent.isDirectory())) {
                throw new BuildException(
                    "Failed to create missing parent directory for %s",
                    zipFile);
            }

            updatedFile = true;
            if (!zipFile.exists() && state.isWithoutAnyResources()) {
                createEmptyZip(zipFile);
                return;
            }
            final Resource[][] addThem = state.getResourcesToAdd();

            if (doUpdate) {
                renamedFile = renameFile();
            }

            final String action = doUpdate ? "Updating " : "Building ";

            if (!skipWriting) {
                log(action + archiveType + ": " + zipFile.getAbsolutePath());
            }

            ZipOutputStream zOut = null;
            try {
                if (!skipWriting) {
                    zOut = new ZipOutputStream(zipFile);

                    zOut.setEncoding(encoding);
                    zOut.setUseLanguageEncodingFlag(useLanguageEncodingFlag);
                    zOut.setCreateUnicodeExtraFields(createUnicodeExtraFields.
                                                     getPolicy());
                    zOut.setFallbackToUTF8(fallBackToUTF8);
                    zOut.setMethod(doCompress
                        ? ZipOutputStream.DEFLATED : ZipOutputStream.STORED);
                    zOut.setLevel(level);
                    zOut.setUseZip64(zip64Mode.getMode());
                }
                initZipOutputStream(zOut);

                // Add the explicit resource collections to the archive.
                for (int i = 0; i < fss.length; i++) {
                    if (addThem[i].length != 0) {
                        addResources(fss[i], addThem[i], zOut);
                    }
                }

                if (doUpdate) {
                    addingNewFiles = false;
                    final ZipFileSet oldFiles = new ZipFileSet();
                    oldFiles.setProject(getProject());
                    oldFiles.setSrc(renamedFile);
                    oldFiles.setDefaultexcludes(false);

                    for (String addedFile : addedFiles) {
                        oldFiles.createExclude().setName(addedFile);
                    }
                    final DirectoryScanner ds =
                        oldFiles.getDirectoryScanner(getProject());
                    ((ZipScanner) ds).setEncoding(encoding);

                    Stream<String> includedResourceNames =
                        Stream.of(ds.getIncludedFiles());

                    if (!doFilesonly) {
                        includedResourceNames =
                            Stream.concat(includedResourceNames,
                                Stream.of(ds.getIncludedDirectories()));
                    }

                    Resource[] r = includedResourceNames.map(ds::getResource)
                        .toArray(Resource[]::new);

                    addResources(oldFiles, r, zOut);
                }
                if (zOut != null) {
                    zOut.setComment(comment);
                }
                finalizeZipOutputStream(zOut);

                // If we've been successful on an update, delete the
                // temporary file
                if (doUpdate) {
                    if (!renamedFile.delete()) {
                        log("Warning: unable to delete temporary file "
                            + renamedFile.getName(), Project.MSG_WARN);
                    }
                }
                success = true;
            } finally {
                // Close the output stream.
                closeZout(zOut, success);
            }
        } catch (final IOException ioe) {
            String msg = "Problem creating " + archiveType + ": "
                + ioe.getMessage();

            // delete a bogus ZIP file (but only if it's not the original one)
            if ((!doUpdate || renamedFile != null) && !zipFile.delete()) {
                msg += " (and the archive is probably corrupt but I could not "
                    + "delete it)";
            }

            if (doUpdate && renamedFile != null) {
                try {
                    FILE_UTILS.rename(renamedFile, zipFile);
                } catch (final IOException e) {
                    msg += " (and I couldn't rename the temporary file "
                            + renamedFile.getName() + " back)";
                }
            }

            throw new BuildException(msg, ioe, getLocation());
        } finally {
            cleanUp();
        }
    }