public List extractData()

in java/clickhouse-client/src/main/java/com/epam/deltix/clickhouse/DescribeTableResultSetExtractor.java [39:91]
40 lines of code
9 McCabe index (conditional complexity)

    public List<ColumnDeclaration> extractData(ResultSet rs) throws SQLException, DataAccessException {

        List<ColumnDeclaration> columns = new ArrayList<>();
        //Map<String, ColumnDeclaration> nestedColumns = new HashMap<>();

        String currentNestedColumn = null;
        List<ColumnDeclaration> currentNestedDataType = null;

        while (rs.next()) {
            String name = rs.getString(FIELD_NAME);
            String type = rs.getString(FIELD_TYPE);
            SqlDataType dataType = ParseProcessor.parseDataType(type);
            String defaultExpression = rs.getString(FIELD_DEFAULT_EXPRESSION);

            // check for nested
            String[] nameParts = name.split("\\.");

            if (nameParts.length == 1) {

                if (currentNestedColumn != null) {
                    columns.add(new ColumnDeclaration(currentNestedColumn, new NestedDataType(currentNestedDataType)));
                    currentNestedColumn = null;
                    currentNestedDataType = null;
                }

                ColumnDeclaration column = new ColumnDeclaration(name, dataType, defaultExpression);
                columns.add(column);
            } else if (nameParts.length == 2) {
                if (currentNestedColumn == null) {
                    currentNestedColumn = nameParts[0];
                    currentNestedDataType = new ArrayList<>();
                } else if (!currentNestedColumn.equals(nameParts[0])) {
                    columns.add(new ColumnDeclaration(currentNestedColumn, new NestedDataType(currentNestedDataType)));
                    currentNestedColumn = nameParts[0];
                    currentNestedDataType = new ArrayList<>();
                }

                if (!(dataType instanceof ArraySqlType))
                    throw new IllegalStateException(String.format("Unexpected data type for nested column '%s' (type)", name));

                SqlDataType elementType = ((ArraySqlType)dataType).getElementType();
                currentNestedDataType.add(new ColumnDeclaration(nameParts[1], elementType, defaultExpression));
            } else {
                throw new IllegalStateException(String.format("Incorrect column name syntax '%s'", name));
            }
        }

        if (currentNestedColumn != null) {
            columns.add(new ColumnDeclaration(currentNestedColumn, new NestedDataType(currentNestedDataType)));
        }

        return columns;
    }