src/ooxml/java/org/apache/poi/xssf/streaming/SheetDataWriter.java - poi - Git at Google

 /*
  *  ====================================================================
  *    Licensed to the Apache Software Foundation (ASF) under one or more
  *    contributor license agreements.  See the NOTICE file distributed with
  *    this work for additional information regarding copyright ownership.
  *    The ASF licenses this file to You under the Apache License, Version 2.0
  *    (the "License"); you may not use this file except in compliance with
  *    the License.  You may obtain a copy of the License at
  *
  *        http://www.apache.org/licenses/LICENSE-2.0
  *
  *    Unless required by applicable law or agreed to in writing, software
  *    distributed under the License is distributed on an "AS IS" BASIS,
  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  *    See the License for the specific language governing permissions and
  *    limitations under the License.
  * ====================================================================
  */

 package org.apache.poi.xssf.streaming;

 import java.io.BufferedWriter;
 import java.io.Closeable;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.Writer;
 import java.nio.charset.StandardCharsets;
 import java.util.Iterator;

 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.poi.ss.usermodel.Cell;
 import org.apache.poi.ss.usermodel.CellStyle;
 import org.apache.poi.ss.usermodel.CellType;
 import org.apache.poi.ss.usermodel.FormulaError;
 import org.apache.poi.ss.util.CellReference;
 import org.apache.poi.util.StringCodepointsIterable;
 import org.apache.poi.util.TempFile;
 import org.apache.poi.xssf.model.SharedStringsTable;
 import org.apache.poi.xssf.usermodel.XSSFRichTextString;
 import org.openxmlformats.schemas.spreadsheetml.x2006.main.STCellType;

 /**
  * Initially copied from BigGridDemo "SpreadsheetWriter".
  * Unlike the original code which wrote the entire document,
  * this class only writes the "sheetData" document fragment
  * so that it was renamed to "SheetDataWriter"
  */
 public class SheetDataWriter implements Closeable {
     private static final Logger LOG = LogManager.getLogger(SheetDataWriter.class);

     private final File _fd;
     protected final Writer _out;
     private int _rownum;
     private int _numberOfFlushedRows;
     private int _lowestIndexOfFlushedRows; // meaningful only of _numberOfFlushedRows>0
     private int _numberOfCellsOfLastFlushedRow; // meaningful only of _numberOfFlushedRows>0
     private int _numberLastFlushedRow = -1; // meaningful only of _numberOfFlushedRows>0

     /**
      * Table of strings shared across this workbook.
      * If two cells contain the same string, then the cell value is the same index into SharedStringsTable
      */
     private SharedStringsTable _sharedStringSource;

     public SheetDataWriter() throws IOException {
         _fd = createTempFile();
         _out = createWriter(_fd);
     }

     public SheetDataWriter(Writer writer) throws IOException {
         _fd = null;
         _out = writer;
     }

     public SheetDataWriter(SharedStringsTable sharedStringsTable) throws IOException {
         this();
         this._sharedStringSource = sharedStringsTable;
     }
     /**
      * Create a temp file to write sheet data.
      * By default, temp files are created in the default temporary-file directory
      * with a prefix "poi-sxssf-sheet" and suffix ".xml".  Subclasses can override
      * it and specify a different temp directory or filename or suffix, e.g. <code>.gz</code>
      *
      * @return temp file to write sheet data
      */
     public File createTempFile() throws IOException {
         return TempFile.createTempFile("poi-sxssf-sheet", ".xml");
     }

     /**
      * Create a writer for the sheet data.
      *
      * @param  fd the file to write to
      */
     public Writer createWriter(File fd) throws IOException {
         FileOutputStream fos = new FileOutputStream(fd);
         OutputStream decorated;
         try {
             decorated = decorateOutputStream(fos);
         } catch (final IOException e) {
             fos.close();
             throw e;
         }
         return new BufferedWriter(
                 new OutputStreamWriter(decorated, StandardCharsets.UTF_8));
     }

     /**
      * Override this to translate (such as encrypt or compress) the file output stream
      * as it is being written to disk.
      * The default behavior is to to pass the stream through unmodified.
      *
      * @param fos  the stream to decorate
      * @return a decorated stream
      * @throws IOException if decorating the stream fails
      * @see #decorateInputStream(FileInputStream)
      */
     protected OutputStream decorateOutputStream(FileOutputStream fos) throws IOException {
         return fos;
     }

     /**
      * flush and close the temp data writer.
      * This method <em>must</em> be invoked before calling {@link #getWorksheetXMLInputStream()}
      */
     public void close() throws IOException {
         // this would break writing the same document multiple times: _out.flush();
         _out.close();
     }

     protected File getTempFile() {
         return _fd;
     }

     /**
      * @return a stream to read temp file with the sheet data
      */
     public InputStream getWorksheetXMLInputStream() throws IOException {
         File fd = getTempFile();
         FileInputStream fis = new FileInputStream(fd);
         try {
             return decorateInputStream(fis);
         } catch (IOException e) {
             fis.close();
             throw e;
         }
     }

     /**
      * Override this to translate (such as decrypt or expand) the file input stream
      * as it is being read from disk.
      * The default behavior is to to pass the stream through unmodified.
      *
      * @param fis  the stream to decorate
      * @return a decorated stream
      * @throws IOException if decorating the stream fails
      * @see #decorateOutputStream(FileOutputStream)
      */
     protected InputStream decorateInputStream(FileInputStream fis) throws IOException {
         return fis;
     }

     public int getNumberOfFlushedRows() {
         return _numberOfFlushedRows;
     }

     public int getNumberOfCellsOfLastFlushedRow() {
         return _numberOfCellsOfLastFlushedRow;
     }

     public int getLowestIndexOfFlushedRows() {
         return _lowestIndexOfFlushedRows;
     }

     public int getLastFlushedRow() {
         return _numberLastFlushedRow;
     }

     @Override
     protected void finalize() throws Throwable {
         if (_fd.exists() && !_fd.delete()) {
             LOG.atError().log("Can't delete temporary encryption file: {}", _fd);
         }
     }

     /**
      * Write a row to the file
      *
      * @param rownum 0-based row number
      * @param row    a row
      *
      * @throws IOException If an I/O error occurs
      */
     public void writeRow(int rownum, SXSSFRow row) throws IOException {
         if (_numberOfFlushedRows == 0)
             _lowestIndexOfFlushedRows = rownum;
         _numberLastFlushedRow = Math.max(rownum, _numberLastFlushedRow);
         _numberOfCellsOfLastFlushedRow = row.getLastCellNum();
         _numberOfFlushedRows++;
         beginRow(rownum, row);
         Iterator<Cell> cells = row.allCellsIterator();
         int columnIndex = 0;
         while (cells.hasNext()) {
             writeCell(columnIndex++, cells.next());
         }
         endRow();
     }

     void beginRow(int rownum, SXSSFRow row) throws IOException {
         _out.write("<row");
         writeAttribute("r", Integer.toString(rownum + 1));
         if (row.hasCustomHeight()) {
             writeAttribute("customHeight", "true");
             writeAttribute("ht", Float.toString(row.getHeightInPoints()));
         }
         if (row.getZeroHeight()) {
             writeAttribute("hidden", "true");
         }
         if (row.isFormatted()) {
             writeAttribute("s", Integer.toString(row.getRowStyleIndex()));
             writeAttribute("customFormat", "1");
         }
         if (row.getOutlineLevel() != 0) {
             writeAttribute("outlineLevel", Integer.toString(row.getOutlineLevel()));
         }
         if(row.getHidden() != null) {
             writeAttribute("hidden", row.getHidden() ? "1" : "0");
         }
         if(row.getCollapsed() != null) {
             writeAttribute("collapsed", row.getCollapsed() ? "1" : "0");
         }

         _out.write(">\n");
         this._rownum = rownum;
     }

     void endRow() throws IOException {
         _out.write("</row>\n");
     }

     public void writeCell(int columnIndex, Cell cell) throws IOException {
         if (cell == null) {
             return;
         }
         String ref = new CellReference(_rownum, columnIndex).formatAsString();
         _out.write("<c");
         writeAttribute("r", ref);
         CellStyle cellStyle = cell.getCellStyle();
         if (cellStyle.getIndex() != 0) {
             // need to convert the short to unsigned short as the indexes can be up to 64k
             // ideally we would use int for this index, but that would need changes to some more
             // APIs
             writeAttribute("s", Integer.toString(cellStyle.getIndex() & 0xffff));
         }
         CellType cellType = cell.getCellType();
         switch (cellType) {
             case BLANK: {
                 _out.write('>');
                 break;
             }
             case FORMULA: {
                 switch(cell.getCachedFormulaResultType()) {
                     case NUMERIC:
                         writeAttribute("t", "n");
                         break;
                     case STRING:
                         writeAttribute("t", STCellType.STR.toString());
                         break;
                     case BOOLEAN:
                         writeAttribute("t", "b");
                         break;
                     case ERROR:
                         writeAttribute("t", "e");
                         break;
                 }
                 _out.write("><f>");
                 outputEscapedString(cell.getCellFormula());
                 _out.write("</f>");
                 switch (cell.getCachedFormulaResultType()) {
                     case NUMERIC:
                         double nval = cell.getNumericCellValue();
                         if (!Double.isNaN(nval)) {
                             _out.write("<v>");
                             _out.write(Double.toString(nval));
                             _out.write("</v>");
                         }
                         break;
                     case STRING:
                         String value = cell.getStringCellValue();
                         if(value != null && !value.isEmpty()) {
                             _out.write("<v>");
                             outputEscapedString(value);
                             _out.write("</v>");
                         }
                         break;
                     case BOOLEAN:
                         _out.write("><v>");
                         _out.write(cell.getBooleanCellValue() ? "1" : "0");
                         _out.write("</v>");
                         break;
                     case ERROR: {
                         FormulaError error = FormulaError.forInt(cell.getErrorCellValue());

                         _out.write("><v>");
                         outputEscapedString(error.getString());
                         _out.write("</v>");
                         break;
                     }
                 }
                 break;
             }
             case STRING: {
                 if (_sharedStringSource != null) {
                     XSSFRichTextString rt = new XSSFRichTextString(cell.getStringCellValue());
                     int sRef = _sharedStringSource.addSharedStringItem(rt);

                     writeAttribute("t", STCellType.S.toString());
                     _out.write("><v>");
                     _out.write(String.valueOf(sRef));
                     _out.write("</v>");
                 } else {
                     writeAttribute("t", "inlineStr");
                     _out.write("><is><t");
                     if (hasLeadingTrailingSpaces(cell.getStringCellValue())) {
                         writeAttribute("xml:space", "preserve");
                     }
                     _out.write(">");
                     outputEscapedString(cell.getStringCellValue());
                     _out.write("</t></is>");
                 }
                 break;
             }
             case NUMERIC: {
                 writeAttribute("t", "n");
                 _out.write("><v>");
                 _out.write(Double.toString(cell.getNumericCellValue()));
                 _out.write("</v>");
                 break;
             }
             case BOOLEAN: {
                 writeAttribute("t", "b");
                 _out.write("><v>");
                 _out.write(cell.getBooleanCellValue() ? "1" : "0");
                 _out.write("</v>");
                 break;
             }
             case ERROR: {
                 FormulaError error = FormulaError.forInt(cell.getErrorCellValue());

                 writeAttribute("t", "e");
                 _out.write("><v>");
                 outputEscapedString(error.getString());
                 _out.write("</v>");
                 break;
             }
             default: {
                 throw new IllegalStateException("Invalid cell type: " + cellType);
             }
         }
         _out.write("</c>");
     }

     private void writeAttribute(String name, String value) throws IOException {
         _out.write(' ');
         _out.write(name);
         _out.write("=\"");
         _out.write(value);
         _out.write('\"');
     }

     /**
      * @return  whether the string has leading / trailing spaces that
      *  need to be preserved with the xml:space=\"preserve\" attribute
      */
     boolean hasLeadingTrailingSpaces(String str) {
         if (str != null && str.length() > 0) {
             char firstChar = str.charAt(0);
             char lastChar  = str.charAt(str.length() - 1);
             return Character.isWhitespace(firstChar) || Character.isWhitespace(lastChar) ;
         }
         return false;
     }

     protected void outputEscapedString(String s) throws IOException {
         if (s == null || s.length() == 0) {
             return;
         }

         for (String codepoint : new StringCodepointsIterable(s)) {
             switch (codepoint) {
                 case "<":
                     _out.write("&lt;");
                     break;
                 case ">":
                     _out.write("&gt;");
                     break;
                 case "&":
                     _out.write("&amp;");
                     break;
                 case "\"":
                     _out.write("&quot;");
                     break;
                 // Special characters
                 case "\n":
                     _out.write("&#xa;");
                     break;
                 case "\r":
                     _out.write("&#xd;");
                     break;
                 case "\t":
                     _out.write("&#x9;");
                     break;
                 case "\u00A0": // NO-BREAK SPACE
                     _out.write("&#xa0;");
                     break;
                 default:
                     if (codepoint.length() == 1) {
                         char c = codepoint.charAt(0);
                         // YK: XmlBeans silently replaces all ISO control characters ( < 32) with question marks.
                         // the same rule applies to "not a character" symbols.
                         if (replaceWithQuestionMark(c)) {
                             _out.write('?');
                         } else {
                             _out.write(c);
                         }
                     } else {
                         _out.write(codepoint);
                     }
                     break;
             }
         }
     }

     static boolean replaceWithQuestionMark(char c) {
         return c < ' ' || ('\uFFFE' <= c && c <= '\uFFFF');
     }

     /**
      * Deletes the temporary file that backed this sheet on disk.
      * @return true if the file was deleted, false if it wasn't.
      */
     boolean dispose() throws IOException {
         final boolean ret;
         try {
             _out.close();
         } finally {
             ret = _fd.delete();
         }
         return ret;
     }
 }
	/*
	* ====================================================================
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	* ====================================================================
	*/

	package org.apache.poi.xssf.streaming;

	import java.io.BufferedWriter;
	import java.io.Closeable;
	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.OutputStream;
	import java.io.OutputStreamWriter;
	import java.io.Writer;
	import java.nio.charset.StandardCharsets;
	import java.util.Iterator;

	import org.apache.logging.log4j.LogManager;
	import org.apache.logging.log4j.Logger;
	import org.apache.poi.ss.usermodel.Cell;
	import org.apache.poi.ss.usermodel.CellStyle;
	import org.apache.poi.ss.usermodel.CellType;
	import org.apache.poi.ss.usermodel.FormulaError;
	import org.apache.poi.ss.util.CellReference;
	import org.apache.poi.util.StringCodepointsIterable;
	import org.apache.poi.util.TempFile;
	import org.apache.poi.xssf.model.SharedStringsTable;
	import org.apache.poi.xssf.usermodel.XSSFRichTextString;
	import org.openxmlformats.schemas.spreadsheetml.x2006.main.STCellType;

	/**
	* Initially copied from BigGridDemo "SpreadsheetWriter".
	* Unlike the original code which wrote the entire document,
	* this class only writes the "sheetData" document fragment
	* so that it was renamed to "SheetDataWriter"
	*/
	public class SheetDataWriter implements Closeable {
	private static final Logger LOG = LogManager.getLogger(SheetDataWriter.class);

	private final File _fd;
	protected final Writer _out;
	private int _rownum;
	private int _numberOfFlushedRows;
	private int _lowestIndexOfFlushedRows; // meaningful only of _numberOfFlushedRows>0
	private int _numberOfCellsOfLastFlushedRow; // meaningful only of _numberOfFlushedRows>0
	private int _numberLastFlushedRow = -1; // meaningful only of _numberOfFlushedRows>0

	/**
	* Table of strings shared across this workbook.
	* If two cells contain the same string, then the cell value is the same index into SharedStringsTable
	*/
	private SharedStringsTable _sharedStringSource;

	public SheetDataWriter() throws IOException {
	_fd = createTempFile();
	_out = createWriter(_fd);
	}

	public SheetDataWriter(Writer writer) throws IOException {
	_fd = null;
	_out = writer;
	}

	public SheetDataWriter(SharedStringsTable sharedStringsTable) throws IOException {
	this();
	this._sharedStringSource = sharedStringsTable;
	}
	/**
	* Create a temp file to write sheet data.
	* By default, temp files are created in the default temporary-file directory
	* with a prefix "poi-sxssf-sheet" and suffix ".xml". Subclasses can override
	* it and specify a different temp directory or filename or suffix, e.g. <code>.gz</code>
	*
	* @return temp file to write sheet data
	*/
	public File createTempFile() throws IOException {
	return TempFile.createTempFile("poi-sxssf-sheet", ".xml");
	}

	/**
	* Create a writer for the sheet data.
	*
	* @param fd the file to write to
	*/
	public Writer createWriter(File fd) throws IOException {
	FileOutputStream fos = new FileOutputStream(fd);
	OutputStream decorated;
	try {
	decorated = decorateOutputStream(fos);
	} catch (final IOException e) {
	fos.close();
	throw e;
	}
	return new BufferedWriter(
	new OutputStreamWriter(decorated, StandardCharsets.UTF_8));
	}

	/**
	* Override this to translate (such as encrypt or compress) the file output stream
	* as it is being written to disk.
	* The default behavior is to to pass the stream through unmodified.
	*
	* @param fos the stream to decorate
	* @return a decorated stream
	* @throws IOException if decorating the stream fails
	* @see #decorateInputStream(FileInputStream)
	*/
	protected OutputStream decorateOutputStream(FileOutputStream fos) throws IOException {
	return fos;
	}

	/**
	* flush and close the temp data writer.
	* This method <em>must</em> be invoked before calling {@link #getWorksheetXMLInputStream()}
	*/
	public void close() throws IOException {
	// this would break writing the same document multiple times: _out.flush();
	_out.close();
	}

	protected File getTempFile() {
	return _fd;
	}

	/**
	* @return a stream to read temp file with the sheet data
	*/
	public InputStream getWorksheetXMLInputStream() throws IOException {
	File fd = getTempFile();
	FileInputStream fis = new FileInputStream(fd);
	try {
	return decorateInputStream(fis);
	} catch (IOException e) {
	fis.close();
	throw e;
	}
	}

	/**
	* Override this to translate (such as decrypt or expand) the file input stream
	* as it is being read from disk.
	* The default behavior is to to pass the stream through unmodified.
	*
	* @param fis the stream to decorate
	* @return a decorated stream
	* @throws IOException if decorating the stream fails
	* @see #decorateOutputStream(FileOutputStream)
	*/
	protected InputStream decorateInputStream(FileInputStream fis) throws IOException {
	return fis;
	}

	public int getNumberOfFlushedRows() {
	return _numberOfFlushedRows;
	}

	public int getNumberOfCellsOfLastFlushedRow() {
	return _numberOfCellsOfLastFlushedRow;
	}

	public int getLowestIndexOfFlushedRows() {
	return _lowestIndexOfFlushedRows;
	}

	public int getLastFlushedRow() {
	return _numberLastFlushedRow;
	}

	@Override
	protected void finalize() throws Throwable {
	if (_fd.exists() && !_fd.delete()) {
	LOG.atError().log("Can't delete temporary encryption file: {}", _fd);
	}
	}

	/**
	* Write a row to the file
	*
	* @param rownum 0-based row number
	* @param row a row
	*
	* @throws IOException If an I/O error occurs
	*/
	public void writeRow(int rownum, SXSSFRow row) throws IOException {
	if (_numberOfFlushedRows == 0)
	_lowestIndexOfFlushedRows = rownum;
	_numberLastFlushedRow = Math.max(rownum, _numberLastFlushedRow);
	_numberOfCellsOfLastFlushedRow = row.getLastCellNum();
	_numberOfFlushedRows++;
	beginRow(rownum, row);
	Iterator<Cell> cells = row.allCellsIterator();
	int columnIndex = 0;
	while (cells.hasNext()) {
	writeCell(columnIndex++, cells.next());
	}
	endRow();
	}

	void beginRow(int rownum, SXSSFRow row) throws IOException {
	_out.write("<row");
	writeAttribute("r", Integer.toString(rownum + 1));
	if (row.hasCustomHeight()) {
	writeAttribute("customHeight", "true");
	writeAttribute("ht", Float.toString(row.getHeightInPoints()));
	}
	if (row.getZeroHeight()) {
	writeAttribute("hidden", "true");
	}
	if (row.isFormatted()) {
	writeAttribute("s", Integer.toString(row.getRowStyleIndex()));
	writeAttribute("customFormat", "1");
	}
	if (row.getOutlineLevel() != 0) {
	writeAttribute("outlineLevel", Integer.toString(row.getOutlineLevel()));
	}
	if(row.getHidden() != null) {
	writeAttribute("hidden", row.getHidden() ? "1" : "0");
	}
	if(row.getCollapsed() != null) {
	writeAttribute("collapsed", row.getCollapsed() ? "1" : "0");
	}

	_out.write(">\n");
	this._rownum = rownum;
	}

	void endRow() throws IOException {
	_out.write("</row>\n");
	}

	public void writeCell(int columnIndex, Cell cell) throws IOException {
	if (cell == null) {
	return;
	}
	String ref = new CellReference(_rownum, columnIndex).formatAsString();
	_out.write("<c");
	writeAttribute("r", ref);
	CellStyle cellStyle = cell.getCellStyle();
	if (cellStyle.getIndex() != 0) {
	// need to convert the short to unsigned short as the indexes can be up to 64k
	// ideally we would use int for this index, but that would need changes to some more
	// APIs
	writeAttribute("s", Integer.toString(cellStyle.getIndex() & 0xffff));
	}
	CellType cellType = cell.getCellType();
	switch (cellType) {
	case BLANK: {
	_out.write('>');
	break;
	}
	case FORMULA: {
	switch(cell.getCachedFormulaResultType()) {
	case NUMERIC:
	writeAttribute("t", "n");
	break;
	case STRING:
	writeAttribute("t", STCellType.STR.toString());
	break;
	case BOOLEAN:
	writeAttribute("t", "b");
	break;
	case ERROR:
	writeAttribute("t", "e");
	break;
	}
	_out.write("><f>");
	outputEscapedString(cell.getCellFormula());
	_out.write("</f>");
	switch (cell.getCachedFormulaResultType()) {
	case NUMERIC:
	double nval = cell.getNumericCellValue();
	if (!Double.isNaN(nval)) {
	_out.write("<v>");
	_out.write(Double.toString(nval));
	_out.write("</v>");
	}
	break;
	case STRING:
	String value = cell.getStringCellValue();
	if(value != null && !value.isEmpty()) {
	_out.write("<v>");
	outputEscapedString(value);
	_out.write("</v>");
	}
	break;
	case BOOLEAN:
	_out.write("><v>");
	_out.write(cell.getBooleanCellValue() ? "1" : "0");
	_out.write("</v>");
	break;
	case ERROR: {
	FormulaError error = FormulaError.forInt(cell.getErrorCellValue());

	_out.write("><v>");
	outputEscapedString(error.getString());
	_out.write("</v>");
	break;
	}
	}
	break;
	}
	case STRING: {
	if (_sharedStringSource != null) {
	XSSFRichTextString rt = new XSSFRichTextString(cell.getStringCellValue());
	int sRef = _sharedStringSource.addSharedStringItem(rt);

	writeAttribute("t", STCellType.S.toString());
	_out.write("><v>");
	_out.write(String.valueOf(sRef));
	_out.write("</v>");
	} else {
	writeAttribute("t", "inlineStr");
	_out.write("><is><t");
	if (hasLeadingTrailingSpaces(cell.getStringCellValue())) {
	writeAttribute("xml:space", "preserve");
	}
	_out.write(">");
	outputEscapedString(cell.getStringCellValue());
	_out.write("</t></is>");
	}
	break;
	}
	case NUMERIC: {
	writeAttribute("t", "n");
	_out.write("><v>");
	_out.write(Double.toString(cell.getNumericCellValue()));
	_out.write("</v>");
	break;
	}
	case BOOLEAN: {
	writeAttribute("t", "b");
	_out.write("><v>");
	_out.write(cell.getBooleanCellValue() ? "1" : "0");
	_out.write("</v>");
	break;
	}
	case ERROR: {
	FormulaError error = FormulaError.forInt(cell.getErrorCellValue());

	writeAttribute("t", "e");
	_out.write("><v>");
	outputEscapedString(error.getString());
	_out.write("</v>");
	break;
	}
	default: {
	throw new IllegalStateException("Invalid cell type: " + cellType);
	}
	}
	_out.write("</c>");
	}

	private void writeAttribute(String name, String value) throws IOException {
	_out.write(' ');
	_out.write(name);
	_out.write("=\"");
	_out.write(value);
	_out.write('\"');
	}

	/**
	* @return whether the string has leading / trailing spaces that
	* need to be preserved with the xml:space=\"preserve\" attribute
	*/
	boolean hasLeadingTrailingSpaces(String str) {
	if (str != null && str.length() > 0) {
	char firstChar = str.charAt(0);
	char lastChar = str.charAt(str.length() - 1);
	return Character.isWhitespace(firstChar) \|\| Character.isWhitespace(lastChar) ;
	}
	return false;
	}

	protected void outputEscapedString(String s) throws IOException {
	if (s == null \|\| s.length() == 0) {
	return;
	}

	for (String codepoint : new StringCodepointsIterable(s)) {
	switch (codepoint) {
	case "<":
	_out.write("<");
	break;
	case ">":
	_out.write(">");
	break;
	case "&":
	_out.write("&");
	break;
	case "\"":
	_out.write(""");
	break;
	// Special characters
	case "\n":
	_out.write(" ");
	break;
	case "\r":
	_out.write(" ");
	break;
	case "\t":
	_out.write(" ");
	break;
	case "\u00A0": // NO-BREAK SPACE
	_out.write(" ");
	break;
	default:
	if (codepoint.length() == 1) {
	char c = codepoint.charAt(0);
	// YK: XmlBeans silently replaces all ISO control characters ( < 32) with question marks.
	// the same rule applies to "not a character" symbols.
	if (replaceWithQuestionMark(c)) {
	_out.write('?');
	} else {
	_out.write(c);
	}
	} else {
	_out.write(codepoint);
	}
	break;
	}
	}
	}

	static boolean replaceWithQuestionMark(char c) {
	return c < ' ' \|\| ('\uFFFE' <= c && c <= '\uFFFF');
	}

	/**
	* Deletes the temporary file that backed this sheet on disk.
	* @return true if the file was deleted, false if it wasn't.
	*/
	boolean dispose() throws IOException {
	final boolean ret;
	try {
	_out.close();
	} finally {
	ret = _fd.delete();
	}
	return ret;
	}
	}