private Headers createHeaders()

in src/main/java/org/apache/commons/csv/CSVParser.java [600:655]
52 lines of code
18 McCabe index (conditional complexity)

    private Headers createHeaders() throws IOException {
        Map<String, Integer> headerMap = null;
        List<String> headerNames = null;
        final String[] formatHeader = format.getHeader();
        if (formatHeader != null) {
            headerMap = createEmptyHeaderMap();
            String[] headerRecord = null;
            if (formatHeader.length == 0) {
                // read the header from the first line of the file
                final CSVRecord nextRecord = nextRecord();
                if (nextRecord != null) {
                    headerRecord = nextRecord.values();
                    headerComment = nextRecord.getComment();
                }
            } else {
                if (format.getSkipHeaderRecord()) {
                    final CSVRecord nextRecord = nextRecord();
                    if (nextRecord != null) {
                        headerComment = nextRecord.getComment();
                    }
                }
                headerRecord = formatHeader;
            }
            // build the name to index mappings
            if (headerRecord != null) {
                // Track an occurrence of a null, empty or blank header.
                boolean observedMissing = false;
                for (int i = 0; i < headerRecord.length; i++) {
                    final String header = headerRecord[i];
                    final boolean blankHeader = CSVFormat.isBlank(header);
                    if (blankHeader && !format.getAllowMissingColumnNames()) {
                        throw new IllegalArgumentException("A header name is missing in " + Arrays.toString(headerRecord));
                    }
                    final boolean containsHeader = blankHeader ? observedMissing : headerMap.containsKey(header);
                    final DuplicateHeaderMode headerMode = format.getDuplicateHeaderMode();
                    final boolean duplicatesAllowed = headerMode == DuplicateHeaderMode.ALLOW_ALL;
                    final boolean emptyDuplicatesAllowed = headerMode == DuplicateHeaderMode.ALLOW_EMPTY;
                    if (containsHeader && !duplicatesAllowed && !(blankHeader && emptyDuplicatesAllowed)) {
                        throw new IllegalArgumentException(String.format(
                                "The header contains a duplicate name: \"%s\" in %s. If this is valid then use CSVFormat.Builder.setDuplicateHeaderMode().",
                                header, Arrays.toString(headerRecord)));
                    }
                    observedMissing |= blankHeader;
                    if (header != null) {
                        headerMap.put(header, Integer.valueOf(i)); // Explicit (un)boxing is intentional
                        if (headerNames == null) {
                            headerNames = new ArrayList<>(headerRecord.length);
                        }
                        headerNames.add(header);
                    }
                }
            }
        }
        // Make header names Collection immutable
        return new Headers(headerMap, headerNames == null ? Collections.emptyList() : Collections.unmodifiableList(headerNames));
    }