Convert Worksheet to CSV

Aspose.Cells - Convert Worksheet to CSV

If developers need to save their files to some storage location then they can simply specify the file name (with its complete storage path) and desired file format (using the FileFormatType enumeration) while calling the save method of Workbook object.

Java

 //Instantiate a new workbook with Excel file path

Workbook workbook = new Workbook(dataPath + "workbook.xls");

//Save the document in PDF format

workbook.save(dataPath + "AsposeWorkbookCSV.csv", SaveFormat.CSV);

Apache POI SS - HSSF & XSSF - Convert Worksheet to CSV

Below code shows how worksheet can be converted to CSV using Apache POI HSSF and XSSF API as compared to Aspose.Cells Java API.

Java

 /**

\* A rudimentary XLSX -> CSV processor modeled on the

\* POI sample program XLS2CSVmra by Nick Burch from the

\* package org.apache.poi.hssf.eventusermodel.examples.

\* Unlike the HSSF version, this one completely ignores

\* missing rows.

\* <p/>

\* Data sheets are read using a SAX parser to keep the

\* memory footprint relatively small, so this should be

\* able to read enormous workbooks.  The styles table and

\* the shared-string table must be kept in memory.  The

\* standard POI styles table class is used, but a custom

\* (read-only) class is used for the shared string table

\* because the standard POI SharedStringsTable grows very

\* quickly with the number of unique strings.

\* <p/>

\* Thanks to Eric Smith for a patch that fixes a problem

\* triggered by cells with multiple "t" elements, which is

\* how Excel represents different formats (e.g., one word

\* plain and one word bold).

\*

\* @author Chris Lott

*/

public class ApacheXLSX2CSV {

 /**

  * The type of the data value is indicated by an attribute on the cell.

  * The value is usually in a "v" element within the cell.

  */

 enum xssfDataType {

     BOOL,

     ERROR,

     FORMULA,

     INLINESTR,

     SSTINDEX,

     NUMBER,

 }


 /**

  * Derived from http://poi.apache.org/spreadsheet/how-to.html#xssf_sax_api

  * <p/>

  * Also see Standard ECMA-376, 1st edition, part 4, pages 1928ff, at

  * http://www.ecma-international.org/publications/standards/Ecma-376.htm

  * <p/>

  * A web-friendly version is http://openiso.org/Ecma/376/Part4

  */

 class MyXSSFSheetHandler extends DefaultHandler {

     /**

      * Table with styles

      */

     private StylesTable stylesTable;

     /**

      * Table with unique strings

      */

     private ReadOnlySharedStringsTable sharedStringsTable;

     /**

      * Destination for data

      */

     private final PrintStream output;

     /**

      * Number of columns to read starting with leftmost

      */

     private final int minColumnCount;

     // Set when V start element is seen

     private boolean vIsOpen;

     // Set when cell start element is seen;

     // used when cell close element is seen.

     private xssfDataType nextDataType;

     // Used to format numeric cell values.

     private short formatIndex;

     private String formatString;

     private final DataFormatter formatter;

     private int thisColumn = -1;

     // The last column printed to the output stream

     private int lastColumnNumber = -1;

     // Gathers characters as they are seen.

     private StringBuffer value;

     /**

      * Accepts objects needed while parsing.

      *

      * @param styles  Table of styles

      * @param strings Table of shared strings

      * @param cols    Minimum number of columns to show

      * @param target  Sink for output

      */

     public MyXSSFSheetHandler(

             StylesTable styles,

             ReadOnlySharedStringsTable strings,

             int cols,

             PrintStream target) {

         this.stylesTable = styles;

         this.sharedStringsTable = strings;

         this.minColumnCount = cols;

         this.output = target;

         this.value = new StringBuffer();

         this.nextDataType = xssfDataType.NUMBER;

         this.formatter = new DataFormatter();

     }

     /*

        * (non-Javadoc)

        * @see org.xml.sax.helpers.DefaultHandler#startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)

        */

     public void startElement(String uri, String localName, String name,

                              Attributes attributes) throws SAXException {

         if ("inlineStr".equals(name) || "v".equals(name)) {

             vIsOpen = true;

             // Clear contents cache

             value.setLength(0);

         }

         // c => cell

         else if ("c".equals(name)) {

             // Get the cell reference

             String r = attributes.getValue("r");

             int firstDigit = -1;

             for (int c = 0; c < r.length(); ++c) {

                 if (Character.isDigit(r.charAt(c))) {

                     firstDigit = c;

                     break;

                 }

             }

             thisColumn = nameToColumn(r.substring(0, firstDigit));

             // Set up defaults.

             this.nextDataType = xssfDataType.NUMBER;

             this.formatIndex = -1;

             this.formatString = null;

             String cellType = attributes.getValue("t");

             String cellStyleStr = attributes.getValue("s");

             if ("b".equals(cellType))

                 nextDataType = xssfDataType.BOOL;

             else if ("e".equals(cellType))

                 nextDataType = xssfDataType.ERROR;

             else if ("inlineStr".equals(cellType))

                 nextDataType = xssfDataType.INLINESTR;

             else if ("s".equals(cellType))

                 nextDataType = xssfDataType.SSTINDEX;

             else if ("str".equals(cellType))

                 nextDataType = xssfDataType.FORMULA;

             else if (cellStyleStr != null) {

                 // It's a number, but almost certainly one

                 //  with a special style or format

                 int styleIndex = Integer.parseInt(cellStyleStr);

                 XSSFCellStyle style = stylesTable.getStyleAt(styleIndex);

                 this.formatIndex = style.getDataFormat();

                 this.formatString = style.getDataFormatString();

                 if (this.formatString == null)

                     this.formatString = BuiltinFormats.getBuiltinFormat(this.formatIndex);

             }

         }

     }

     /*

        * (non-Javadoc)

        * @see org.xml.sax.helpers.DefaultHandler#endElement(java.lang.String, java.lang.String, java.lang.String)

        */

     public void endElement(String uri, String localName, String name)

             throws SAXException {

         String thisStr = null;

         // v => contents of a cell

         if ("v".equals(name)) {

             // Process the value contents as required.

             // Do now, as characters() may be called more than once

             switch (nextDataType) {

                 case BOOL:

                     char first = value.charAt(0);

                     thisStr = first == '0' ? "FALSE" : "TRUE";

                     break;

                 case ERROR:

                     thisStr = "\"ERROR:" + value.toString() + '"';

                     break;

                 case FORMULA:

                     // A formula could result in a string value,

                     // so always add double-quote characters.

                     thisStr = '"' + value.toString() + '"';

                     break;

                 case INLINESTR:

                     // TODO: have seen an example of this, so it's untested.

                     XSSFRichTextString rtsi = new XSSFRichTextString(value.toString());

                     thisStr = '"' + rtsi.toString() + '"';

                     break;

                 case SSTINDEX:

                     String sstIndex = value.toString();

                     try {

                         int idx = Integer.parseInt(sstIndex);

                         XSSFRichTextString rtss = new XSSFRichTextString(sharedStringsTable.getEntryAt(idx));

                         thisStr = '"' + rtss.toString() + '"';

                     }

                     catch (NumberFormatException ex) {

                         output.println("Failed to parse SST index '" + sstIndex + "': " + ex.toString());

                     }

                     break;

                 case NUMBER:

                     String n = value.toString();

                     if (this.formatString != null)

                         thisStr = formatter.formatRawCellContents(Double.parseDouble(n), this.formatIndex, this.formatString);

                     else

                         thisStr = n;

                     break;

                 default:

                     thisStr = "(TODO: Unexpected type: " + nextDataType + ")";

                     break;

             }

             // Output after we've seen the string contents

             // Emit commas for any fields that were missing on this row

             if (lastColumnNumber == -1) {

                 lastColumnNumber = 0;

             }

             for (int i = lastColumnNumber; i < thisColumn; ++i)

                 output.print(',');

             // Might be the empty string.

             output.print(thisStr);

             // Update column

             if (thisColumn > -1)

                 lastColumnNumber = thisColumn;

         } else if ("row".equals(name)) {

             // Print out any missing commas if needed

             if (minColumns > 0) {

                 // Columns are 0 based

                 if (lastColumnNumber == -1) {

                     lastColumnNumber = 0;

                 }

                 for (int i = lastColumnNumber; i < (this.minColumnCount); i++) {

                     output.print(',');

                 }

             }

             // We're onto a new row

             output.println();

             lastColumnNumber = -1;

         }

     }

     /**

      * Captures characters only if a suitable element is open.

      * Originally was just "v"; extended for inlineStr also.

      */

     public void characters(char[] ch, int start, int length)

             throws SAXException {

         if (vIsOpen)

             value.append(ch, start, length);

     }

     /**

      * Converts an Excel column name like "C" to a zero-based index.

      *

      * @param name

      * @return Index corresponding to the specified name

      */

     private int nameToColumn(String name) {

         int column = -1;

         for (int i = 0; i < name.length(); ++i) {

             int c = name.charAt(i);

             column = (column + 1) * 26 + c - 'A';

         }

         return column;

     }

 }

 ///////////////////////////////////////

 private OPCPackage xlsxPackage;

 private int minColumns;

 private PrintStream output;

 /**

  * Creates a new XLSX -> CSV converter

  *

  * @param pkg        The XLSX package to process

  * @param output     The PrintStream to output the CSV to

  * @param minColumns The minimum number of columns to output, or -1 for no minimum

  */

 public ApacheXLSX2CSV(OPCPackage pkg, PrintStream output, int minColumns) {

     this.xlsxPackage = pkg;

     this.output = output;

     this.minColumns = minColumns;

 }

 /**

  * Parses and shows the content of one sheet

  * using the specified styles and shared-strings tables.

  *

  * @param styles

  * @param strings

  * @param sheetInputStream

  */

 public void processSheet(

         StylesTable styles,

         ReadOnlySharedStringsTable strings,

         InputStream sheetInputStream)

         throws IOException, ParserConfigurationException, SAXException {

     InputSource sheetSource = new InputSource(sheetInputStream);

     SAXParserFactory saxFactory = SAXParserFactory.newInstance();

     SAXParser saxParser = saxFactory.newSAXParser();

     XMLReader sheetParser = saxParser.getXMLReader();

     ContentHandler handler = new MyXSSFSheetHandler(styles, strings, this.minColumns, this.output);

     sheetParser.setContentHandler(handler);

     sheetParser.parse(sheetSource);

 }

 /**

  * Initiates the processing of the XLS workbook file to CSV.

  *

  * @throws IOException

  * @throws OpenXML4JException

  * @throws ParserConfigurationException

  * @throws SAXException

  */

 public void process()

         throws IOException, OpenXML4JException, ParserConfigurationException, SAXException {

     ReadOnlySharedStringsTable strings = new ReadOnlySharedStringsTable(this.xlsxPackage);

     XSSFReader xssfReader = new XSSFReader(this.xlsxPackage);

     StylesTable styles = xssfReader.getStylesTable();

     XSSFReader.SheetIterator iter = (XSSFReader.SheetIterator) xssfReader.getSheetsData();

     int index = 0;

     while (iter.hasNext()) {

         InputStream stream = iter.next();

         String sheetName = iter.getSheetName();

         this.output.println();

         this.output.println(sheetName + " [index=" + index + "]:");

         processSheet(styles, strings, stream);

         stream.close();

         ++index;

     }

 }

 public static void main(String[] args) throws Exception

 {

	String dataPath = "src/featurescomparison/workingwithworksheets/converttocsv/data/";

     File xlsxFile = new File(dataPath + "workbook.xls");

     if (!xlsxFile.exists())

     {

         System.err.println("Not found or not a file: " + xlsxFile.getPath());

         return;

     }

     int minColumns = -1;

     if (args.length >= 2)

         minColumns = Integer.parseInt(args[1]);

     // The package open is instantaneous, as it should be.

     OPCPackage p = OPCPackage.open(xlsxFile.getPath(), PackageAccess.READ);

     ApacheXLSX2CSV xlsx2csv = new ApacheXLSX2CSV(p, System.out, minColumns);

     xlsx2csv.process();

}

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