Java tutorial
// ============================================================================ // // Copyright (C) 2006-2016 Talend Inc. - www.talend.com // // This source code is available under agreement available at // https://github.com/Talend/data-prep/blob/master/LICENSE // // You should have received a copy of the agreement // along with this program; if not, write to Talend SA // 9 rue Pages 92150 Suresnes, France // // ============================================================================ package org.talend.dataprep.schema.xls; import static org.talend.dataprep.api.type.Type.*; import java.io.IOException; import java.io.InputStream; import java.io.PushbackInputStream; import java.util.ArrayList; import java.util.Collections; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.OptionalLong; import java.util.SortedMap; import java.util.TreeMap; import java.util.stream.Collectors; import org.apache.commons.lang.StringUtils; import org.apache.poi.hssf.usermodel.HSSFDateUtil; import org.apache.poi.ss.usermodel.Cell; import org.apache.poi.ss.usermodel.FormulaEvaluator; import org.apache.poi.ss.usermodel.Row; import org.apache.poi.ss.usermodel.Sheet; import org.apache.poi.ss.usermodel.Workbook; import org.apache.poi.ss.usermodel.WorkbookFactory; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.slf4j.Marker; import org.springframework.stereotype.Service; import org.talend.dataprep.api.dataset.ColumnMetadata; import org.talend.dataprep.api.type.Type; import org.talend.dataprep.exception.TDPException; import org.talend.dataprep.exception.error.CommonErrorCodes; import org.talend.dataprep.exception.error.DataSetErrorCodes; import org.talend.dataprep.log.Markers; import org.talend.dataprep.schema.Schema; import org.talend.dataprep.schema.SchemaParser; import org.talend.dataprep.schema.xls.streaming.StreamingReader; import org.talend.dataprep.schema.xls.streaming.StreamingSheet; /** * This class is in charge of parsing excel file (note apache poi is used for reading .xls) * @see <a hrerf="https://poi.apache.org/ */ @Service("parser#xls") public class XlsSchemaParser implements SchemaParser { /** This class' logger. */ private static final Logger LOGGER = LoggerFactory.getLogger(XlsSchemaParser.class); /** Constant used to record blank cell. */ private static final String BLANK = "blank"; /** * @see SchemaParser#parse(Request) */ @Override public Schema parse(Request request) { final Marker marker = Markers.dataset(request.getMetadata().getId()); LOGGER.debug(marker, "parsing {} "); try { List<Schema.SheetContent> sheetContents = parseAllSheets(request); Schema result; if (!sheetContents.isEmpty()) { // only one sheet if (sheetContents.size() == 1) { result = Schema.Builder.parserResult() // .sheetContents(sheetContents) // .draft(false) // .sheetName(sheetContents.get(0).getName()) // .build(); } // multiple sheet, set draft flag on else { result = Schema.Builder.parserResult() // .sheetContents(sheetContents) // .draft(true) // .sheetName(sheetContents.get(0).getName()) // .build(); } } // nothing to parse else { throw new TDPException(DataSetErrorCodes.UNABLE_TO_READ_DATASET_CONTENT); } return result; } catch (TDPException e) { throw e; } catch (Exception e) { LOGGER.debug(marker, "IOException during parsing xls request :" + e.getMessage(), e); throw new TDPException(CommonErrorCodes.UNEXPECTED_EXCEPTION, e); } } /** * Parse all xls sheets. * * @param request the schema parser request. * @return the list of parsed xls sheet. * @throws IOException if an error occurs. */ protected List<Schema.SheetContent> parseAllSheets(Request request) throws IOException { InputStream inputStream = request.getContent(); if (!inputStream.markSupported()) { inputStream = new PushbackInputStream(inputStream, 8); } boolean newExcelFormat = XlsUtils.isNewExcelFormat(inputStream); // parse the xls input stream using the correct format if (newExcelFormat) { return parseAllSheetsStream(new Request(inputStream, request.getMetadata())); } else { return parseAllSheetsOldFormat(new Request(inputStream, request.getMetadata())); } } private List<Schema.SheetContent> parseAllSheetsStream(Request request) { Workbook workbook = StreamingReader.builder() // .bufferSize(4096) // .rowCacheSize(1) // .open(request.getContent()); try { List<Schema.SheetContent> schemas = new ArrayList<>(); int sheetNumber = 0; for (Sheet sheet : workbook) { List<ColumnMetadata> columnsMetadata = new ArrayList<>(); int rowNumber = 0; for (Row r : sheet) { if (rowNumber < 1) { if (((StreamingSheet) sheet).getReader().getFirstRowIndex() == 1) { for (Cell c : r) { String headerText = StringUtils.trim(c.getStringCellValue()); // header text cannot be null so use a default one if (StringUtils.isEmpty(headerText)) { headerText = "col_" + (columnsMetadata.size() + 1); // +1 because it starts from 0 } columnsMetadata.add(ColumnMetadata.Builder // .column() // .name(headerText) // .type(Type.STRING) // .headerSize(1) // .build()); } } } else { break; } rowNumber++; } String sheetName = sheet.getSheetName(); Schema.SheetContent sheetContent = new Schema.SheetContent( StringUtils.isEmpty(sheetName) ? "sheet-" + sheetNumber : sheetName, columnsMetadata); int maxColNumber = ((StreamingSheet) sheet).getReader().getColNumber(); String dimension = ((StreamingSheet) sheet).getReader().getDimension(); if (StringUtils.isNotEmpty(dimension)) { int maxColNumberFromDimension = XlsUtils.getColumnsNumberFromDimension(dimension); // well for some files they can disagree so we use the biggest one if (maxColNumberFromDimension > maxColNumber) { maxColNumber = maxColNumberFromDimension; } } // if less columns found than the metadata we complete if (columnsMetadata.size() < maxColNumber) { int size = maxColNumber - columnsMetadata.size(); for (int j = 0; j < size; j++) { columnsMetadata.add(ColumnMetadata.Builder // .column() // .name("col_" + j) // .type(Type.STRING) // .headerSize(1) // .build()); } } schemas.add(sheetContent); } return schemas; } finally { try { workbook.close(); } catch (IOException e) { LOGGER.error("Unable to close excel file.", e); } } } /** * Parse all xls sheets for old excel document type * * @param request the xls request. * @return The parsed sheets request. */ private List<Schema.SheetContent> parseAllSheetsOldFormat(Request request) { final Marker marker = Markers.dataset(request.getMetadata().getId()); try { InputStream inputStream = request.getContent(); if (!inputStream.markSupported()) { inputStream = new PushbackInputStream(inputStream, 8); } Workbook hssfWorkbook = WorkbookFactory.create(inputStream); List<Schema.SheetContent> schemas; try { if (hssfWorkbook == null) { throw new IOException("could not open " + request.getMetadata().getId() + " as an excel file"); } int sheetNumber = hssfWorkbook.getNumberOfSheets(); if (sheetNumber < 1) { LOGGER.debug(marker, "has not sheet to read"); return Collections.emptyList(); } schemas = new ArrayList<>(); for (int i = 0; i < sheetNumber; i++) { Sheet sheet = hssfWorkbook.getSheetAt(i); if (sheet.getLastRowNum() < 1) { LOGGER.debug(marker, "sheet '{}' do not have rows skip ip", sheet.getSheetName()); continue; } List<ColumnMetadata> columnsMetadata = parsePerSheet(sheet, // request.getMetadata().getId(), // hssfWorkbook.getCreationHelper().createFormulaEvaluator()); String sheetName = sheet.getSheetName(); // update XlsSerializer if this default sheet naming change!!! schemas.add( new Schema.SheetContent(sheetName == null ? "sheet-" + i : sheetName, columnsMetadata)); } } finally { hssfWorkbook.close(); } return schemas; } catch (Exception e) { LOGGER.debug(marker, "Exception during parsing xls request :" + e.getMessage(), e); throw new TDPException(CommonErrorCodes.UNEXPECTED_EXCEPTION, e); } } /** * Return the columns metadata for the given sheet. * * @param sheet the sheet to look at. * @param datasetId the dataset id. * @return the columns metadata for the given sheet. */ private List<ColumnMetadata> parsePerSheet(Sheet sheet, String datasetId, FormulaEvaluator formulaEvaluator) { LOGGER.debug(Markers.dataset(datasetId), "parsing sheet '{}'", sheet.getSheetName()); // Map<ColId, Map<RowId, type>> SortedMap<Integer, SortedMap<Integer, String>> cellsTypeMatrix = collectSheetTypeMatrix(sheet, formulaEvaluator); int averageHeaderSize = guessHeaderSize(cellsTypeMatrix); // here we have information regarding types for each rows/col (yup a Matrix!! :-) ) // so we can analyse and guess metadata (column type, header value) final List<ColumnMetadata> columnsMetadata = new ArrayList<>(cellsTypeMatrix.size()); cellsTypeMatrix.forEach((colId, typePerRowMap) -> { Type type = guessColumnType(colId, typePerRowMap, averageHeaderSize); String headerText = "col" + colId; if (averageHeaderSize == 1 && sheet.getRow(0) != null) { // so header value is the first row of the column Cell headerCell = sheet.getRow(0).getCell(colId); headerText = XlsUtils.getCellValueAsString(headerCell, formulaEvaluator); } // header text cannot be null so use a default one if (StringUtils.isEmpty(headerText)) { headerText = "col_" + (colId + 1); // +1 because it starts from 0 } // FIXME what do we do if header size is > 1 concat all lines? columnsMetadata.add(ColumnMetadata.Builder // .column() // .headerSize(averageHeaderSize) // .name(headerText) // .type(type) // .build()); }); return columnsMetadata; } /** * * * @param colId the column id. * @param columnRows all rows with previously guessed type: key=row number, value= guessed type * @param averageHeaderSize * @return */ private Type guessColumnType(Integer colId, SortedMap<Integer, String> columnRows, int averageHeaderSize) { // calculate number per type Map<String, Long> perTypeNumber = columnRows.tailMap(averageHeaderSize).values() // .stream() // .collect(Collectors.groupingBy(w -> w, Collectors.counting())); OptionalLong maxOccurrence = perTypeNumber.values().stream().mapToLong(Long::longValue).max(); if (!maxOccurrence.isPresent()) { return ANY; } List<String> duplicatedMax = new ArrayList<>(); perTypeNumber.forEach((type1, aLong) -> { if (aLong >= maxOccurrence.getAsLong()) { duplicatedMax.add(type1); } }); String guessedType; if (duplicatedMax.size() == 1) { guessedType = duplicatedMax.get(0); } else { // as we have more than one type we guess ANY guessedType = ANY.getName(); } LOGGER.debug("guessed type for column #{} is {}", colId, guessedType); return Type.get(guessedType); } /** * We store (cell types per row) per column. * * @param sheet key is the column number, value is a Map with key row number and value Type * @return A Map<colId, Map<rowId, type>> */ private SortedMap<Integer, SortedMap<Integer, String>> collectSheetTypeMatrix(Sheet sheet, FormulaEvaluator formulaEvaluator) { int firstRowNum = sheet.getFirstRowNum(); int lastRowNum = sheet.getLastRowNum(); LOGGER.debug("firstRowNum: {}, lastRowNum: {}", firstRowNum, lastRowNum); SortedMap<Integer, SortedMap<Integer, String>> cellsTypeMatrix = new TreeMap<>(); // we start analysing rows for (int rowCounter = firstRowNum; rowCounter <= lastRowNum; rowCounter++) { int cellCounter = 0; Row row = sheet.getRow(rowCounter); if (row == null) { continue; } Iterator<Cell> cellIterator = row.cellIterator(); String currentType; while (cellIterator.hasNext()) { Cell cell = cellIterator.next(); int xlsType = Cell.CELL_TYPE_STRING; try { xlsType = cell.getCellType() == Cell.CELL_TYPE_FORMULA ? // formulaEvaluator.evaluate(cell).getCellType() : cell.getCellType(); } catch (Exception e) { // ignore formula error evaluation get as a String with the formula } switch (xlsType) { case Cell.CELL_TYPE_BOOLEAN: currentType = BOOLEAN.getName(); break; case Cell.CELL_TYPE_NUMERIC: currentType = getTypeFromNumericCell(cell); break; case Cell.CELL_TYPE_BLANK: currentType = BLANK; break; case Cell.CELL_TYPE_FORMULA: case Cell.CELL_TYPE_STRING: currentType = STRING.getName(); break; case Cell.CELL_TYPE_ERROR: // we cannot really do anything with an error default: currentType = ANY.getName(); } SortedMap<Integer, String> cellInfo = cellsTypeMatrix.get(cellCounter); if (cellInfo == null) { cellInfo = new TreeMap<>(); } cellInfo.put(rowCounter, currentType); cellsTypeMatrix.put(cellCounter, cellInfo); cellCounter++; } } LOGGER.trace("cellsTypeMatrix: {}", cellsTypeMatrix); return cellsTypeMatrix; } private String getTypeFromNumericCell(Cell cell) { try { return HSSFDateUtil.isCellDateFormatted(cell) ? DATE.getName() : NUMERIC.getName(); } catch (IllegalStateException e) { return ANY.getName(); } } /** * <p> * As we can try to be smart and user friendly and not those nerd devs who doesn't mind about users so we try to * guess the header size (we assume those bloody users don't have complicated headers!!) * </p> * <p> * We scan all entries to find a common header size value (i.e row line with value type change) more simple all * columns/lines with type String * </p> * * @param cellsTypeMatrix key: column number value: row where the type change from String to something else * @return The guessed header size. */ private int guessHeaderSize(Map<Integer, SortedMap<Integer, String>> cellsTypeMatrix) { SortedMap<Integer, Integer> cellTypeChange = new TreeMap<>(); cellsTypeMatrix.forEach((colId, typePerRow) -> { String firstType = null; int rowChange = 0; for (Map.Entry<Integer, String> typePerRowEntry : typePerRow.entrySet()) { if (firstType == null) { firstType = typePerRowEntry.getValue(); } else { if (!typePerRowEntry.getValue().equals(firstType) && !typePerRowEntry.getValue().equals(STRING.getName())) { rowChange = typePerRowEntry.getKey(); break; } } } cellTypeChange.put(colId, rowChange); firstType = null; rowChange = 0; }); // FIXME think more about header size calculation // currently can fail so force an header of size 1 int averageHeaderSize = 1; LOGGER.debug("averageHeaderSize (forced to): {}, cellTypeChange: {}", averageHeaderSize, cellTypeChange); return averageHeaderSize; } }