org.apache.poi.EmptyFileException Java Examples

/**
 * Peeks at the first N bytes of the stream. Returns those bytes, but
 *  with the stream unaffected. Requires a stream that supports mark/reset,
 *  or a PushbackInputStream. If the stream has >0 but <N bytes, 
 *  remaining bytes will be zero.
 * @throws EmptyFileException if the stream is empty
 */
public static byte[] peekFirstNBytes(InputStream stream, int limit) throws IOException, EmptyFileException {
    stream.mark(limit);
    ByteArrayOutputStream bos = new ByteArrayOutputStream(limit);
    copy(new BoundedInputStream(stream, limit), bos);

    int readBytes = bos.size();
    if (readBytes == 0) {
        throw new EmptyFileException();
    }
    
    if (readBytes < limit) {
        bos.write(new byte[limit-readBytes]);
    }
    byte peekedBytes[] = bos.toByteArray();
    if(stream instanceof PushbackInputStream) {
        PushbackInputStream pin = (PushbackInputStream)stream;
        pin.unread(peekedBytes, 0, readBytes);
    } else {
        stream.reset();
    }

    return peekedBytes;
}
 

/**
 * Reads a list of POJOs from the given excel file.
 *
 * @param path Excel file to read from
 * @param sheetName The sheet to extract from in the workbook
 * @param reader The reader class to use to load the file from the sheet
 */
public static void process(String path, String sheetName, ZeroCellReader reader) {
    if (path == null || path.trim().isEmpty()) {
        throw new IllegalArgumentException("'path' must be given");
    }

    File file = new File(path);
    if (file.exists() && file.isDirectory()) {
        throw new IllegalArgumentException("path must not be a directory");
    }
    try (OPCPackage opcPackage = OPCPackage.open(file.getAbsolutePath(), PackageAccess.READ)) {
        process(opcPackage, sheetName, reader);
    } catch(InvalidFormatException | EmptyFileException | NotOfficeXmlFileException ife) {
        throw new ZeroCellException(ERROR_NOT_OPENXML);
    } catch (IOException ioe) {
        throw new ZeroCellException("Failed to process file", ioe);
    }
}
 

/**
 * Reads a list of POJOs from the given excel file.
 *
 * @param file Excel file to read from
 * @param sheetName The sheet to extract from in the workbook
 * @param reader The reader class to use to load the file from the sheet
 */
public static void process(File file, String sheetName, ZeroCellReader reader) {
    try (OPCPackage opcPackage = OPCPackage.open(file, PackageAccess.READ)) {
        process(opcPackage, sheetName, reader);
    } catch(InvalidFormatException | EmptyFileException | NotOfficeXmlFileException ife) {
        throw new ZeroCellException(ERROR_NOT_OPENXML);
    } catch (IOException ioe) {
        throw new ZeroCellException("Failed to process file", ioe);
    }
}
 

@Test(expected = EmptyFileException.class)
public void testEmptyDoc() throws InvalidFormatException, IOException {
    final File file = new File("resources/document/empty/empty-template.docx");
    assertTrue(file.exists());
    try (FileInputStream is = new FileInputStream(file);
            OPCPackage oPackage = OPCPackage.open(is);
            XWPFDocument document = new XWPFDocument(oPackage);) {
        TokenIterator iterator = new TokenIterator(document);

        assertTrue(!iterator.hasNext());
    }
}
 

/**
 * Processes data from an Excel file contained in the OPCPackage using the
 * reader implementation
 * <p>
 * Please note that the process will read data from the first sheet in the
 * File when if sheet name is not specified
 * (i.e. the sheet name defaults to the {@link EntityHandler.DEFAULT_SHEET})
 * </p>
 * @param opcPackage the OpenXML OPC Package
 * @param sheetName The sheet name
 * @param reader the reader implementation that handles the entity mapping
 */
private static void process(OPCPackage opcPackage, String sheetName, ZeroCellReader reader) {
    try {
        DataFormatter dataFormatter = new DataFormatter();
        ReadOnlySharedStringsTable strings = new ReadOnlySharedStringsTable(opcPackage);
        XSSFReader xssfReader = new XSSFReader(opcPackage);
        StylesTable stylesTable = xssfReader.getStylesTable();
        InputStream sheetInputStream = null;
        XSSFReader.SheetIterator sheets = (XSSFReader.SheetIterator) xssfReader.getSheetsData();
        while (sheets.hasNext()) {
            sheetInputStream = sheets.next();

            if (EntityHandler.DEFAULT_SHEET.equalsIgnoreCase(sheetName)) {
                break;
            }
            if (sheets.getSheetName().equalsIgnoreCase(sheetName)) {
                break;
            } else {
                sheetInputStream = null;
            }
        }

        if (Objects.isNull(sheetInputStream)) {
            throw new SheetNotFoundException(sheetName);
        }

        XMLReader xmlReader = SAXHelper.newXMLReader();
        xmlReader.setContentHandler(new XSSFSheetXMLHandler(stylesTable, strings, reader, dataFormatter, false));
        xmlReader.parse(new InputSource(sheetInputStream));
        sheetInputStream.close();
        xmlReader = null;
        sheetInputStream = null;
        stylesTable = null;
        strings = null;
        xssfReader = null;
    } catch(InvalidFormatException | EmptyFileException | NotOfficeXmlFileException ife) {
        throw new ZeroCellException(ERROR_NOT_OPENXML);
    } catch(SheetNotFoundException ex) {
        throw new ZeroCellException(ex.getMessage());
    } catch (ZeroCellException ze) {
        throw ze; // Rethrow the Exception
    } catch (Exception e) {
        throw new ZeroCellException("Failed to process file", e);
    }
}
 

/**
 * Peeks at the first 8 bytes of the stream. Returns those bytes, but
 *  with the stream unaffected. Requires a stream that supports mark/reset,
 *  or a PushbackInputStream. If the stream has >0 but <8 bytes, 
 *  remaining bytes will be zero.
 * @throws EmptyFileException if the stream is empty
 */
public static byte[] peekFirst8Bytes(InputStream stream) throws IOException, EmptyFileException {
    return peekFirstNBytes(stream, 8);
}