--- src/ooxml/java/org/apache/poi/xssf/streaming/GZIPSheetDataWriter.java	(revision 1516092)
+++ src/ooxml/java/org/apache/poi/xssf/streaming/GZIPSheetDataWriter.java	(working copy)
@@ -22,14 +22,15 @@ 
 import java.io.*;
 import java.util.zip.GZIPInputStream;
 import java.util.zip.GZIPOutputStream;
+import org.apache.poi.xssf.model.SharedStringsTable;
 
 /**
  * Sheet writer that supports gzip compression of the temp files.
  */
 public class GZIPSheetDataWriter extends SheetDataWriter {
 
-    public GZIPSheetDataWriter() throws IOException {
-        super();
+    public GZIPSheetDataWriter(SharedStringsTable sharedStringsTable) throws IOException {
+        super(sharedStringsTable);
     }
 
     /**
--- src/ooxml/java/org/apache/poi/xssf/streaming/SheetDataWriter.java	(revision 1516092)
+++ src/ooxml/java/org/apache/poi/xssf/streaming/SheetDataWriter.java	(working copy)
@@ -23,12 +23,11 @@ 
 import org.apache.poi.ss.usermodel.CellStyle;
 import org.apache.poi.ss.usermodel.FormulaError;
 import org.apache.poi.ss.util.CellReference;
-import org.apache.xmlbeans.XmlCursor;
-import org.openxmlformats.schemas.spreadsheetml.x2006.main.STXstring;
-
-import javax.xml.namespace.QName;
 import java.io.*;
 import java.util.Iterator;
+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".
@@ -46,11 +45,21 @@ 
     int _numberOfCellsOfLastFlushedRow; // meaningful only of _numberOfFlushedRows>0
     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(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
@@ -188,14 +197,24 @@ 
                 break;
             }
             case Cell.CELL_TYPE_STRING: {
-                _out.write(" t=\"inlineStr\">");
-                _out.write("<is><t");
-                if(hasLeadingTrailingSpaces(cell.getStringCellValue())) {
-                    _out.write(" xml:space=\"preserve\"");
+                if (_sharedStringSource != null) {
+                    XSSFRichTextString rt = new XSSFRichTextString(cell.getStringCellValue());
+                    int sRef = _sharedStringSource.addEntry(rt.getCTRst());
+
+                    _out.write(" t=\"" + STCellType.S.toString() + "\">");
+                    _out.write("<v>");
+                    _out.write(String.valueOf(sRef));
+                    _out.write("</v>");
+                } else {
+                    _out.write(" t=\"inlineStr\">");
+                    _out.write("<is><t");
+                    if (hasLeadingTrailingSpaces(cell.getStringCellValue())) {
+                        _out.write(" xml:space=\"preserve\"");
+                    }
+                    _out.write(">");
+                    outputQuotedString(cell.getStringCellValue());
+                    _out.write("</t></is>");
                 }
-                _out.write(">");
-                outputQuotedString(cell.getStringCellValue());
-                _out.write("</t></is>");
                 break;
             }
             case Cell.CELL_TYPE_NUMERIC: {
@@ -237,7 +256,7 @@ 
     }
 
     //Taken from jdk1.3/src/javax/swing/text/html/HTMLWriter.java
-    protected void outputQuotedString(String s) throws IOException {
+     protected void outputQuotedString(String s) throws IOException {
         if (s == null || s.length() == 0) {
             return;
         }
--- src/ooxml/java/org/apache/poi/xssf/streaming/SXSSFWorkbook.java	(revision 1516092)
+++ src/ooxml/java/org/apache/poi/xssf/streaming/SXSSFWorkbook.java	(working copy)
@@ -43,6 +43,7 @@ 
 import org.apache.poi.ss.formula.udf.UDFFinder;
 import org.apache.poi.ss.usermodel.Row.MissingCellPolicy;
 import org.apache.poi.ss.util.CellRangeAddress;
+import org.apache.poi.xssf.model.SharedStringsTable;
 
 /**
  * Streaming version of XSSFWorkbook implementing the "BigGridDemo" strategy.
@@ -73,6 +74,11 @@ 
     private boolean _compressTmpFiles = false;
 
     /**
+     * shared string table - a cache of strings in this workbook
+     */
+    private SharedStringsTable _sharedStringSource = null;
+
+    /**
      * Construct a new workbook
      */
     public SXSSFWorkbook(){
@@ -80,6 +86,17 @@ 
     }
 
     /**
+     * Construct a new workbook
+     * <p></p>
+     * Whether to use shared string table or not
+     * </p>
+     * @param useSahredStringTable
+     */
+    public SXSSFWorkbook(boolean useSahredStringTable){
+    	this(null /*workbook*/, useSahredStringTable);
+    }
+
+    /**
      * Construct a workbook from a template.
      * <p>
      * There are three use-cases to use SXSSFWorkbook(XSSFWorkbook) :
@@ -115,11 +132,53 @@ 
      * @param workbook  the template workbook
      */
     public SXSSFWorkbook(XSSFWorkbook workbook){
-    	this(workbook, DEFAULT_WINDOW_SIZE);
+    	this(workbook, DEFAULT_WINDOW_SIZE, false);
     }
-    
 
     /**
+     * Construct a workbook from a template.
+     * <p>
+     * There are three use-cases to use SXSSFWorkbook(XSSFWorkbook) :
+     * <ol>
+     *   <li>
+     *       Append new sheets to existing workbooks. You can open existing
+     *       workbook from a file or create on the fly with XSSF.
+     *   </li>
+     *   <li>
+     *       Append rows to existing sheets. The row number MUST be greater
+     *       than max(rownum) in the template sheet.
+     *   </li>
+     *   <li>
+     *       Use existing workbook as a template and re-use global objects such
+     *       as cell styles, formats, images, etc.
+     *   </li>
+     * </ol>
+     * All three use cases can work in a combination.
+     * </p>
+     * What is not supported:
+     * <ul>
+     *   <li>
+     *   Access initial cells and rows in the template. After constructing
+     *   SXSSFWorkbook(XSSFWorkbook) all internal windows are empty and
+     *   SXSSFSheet@getRow and SXSSFRow#getCell return null.
+     *   </li>
+     *   <li>
+     *    Override existing cells and rows. The API silently allows that but
+     *    the output file is invalid and Excel cannot read it.
+     *   </li>
+     * </ul>
+     *
+     * @param workbook  the template workbook
+     * <p></p>
+     * Whether to use shared string table or not
+     * </p>
+     * @param useSahredStringTable
+     */
+    public SXSSFWorkbook(XSSFWorkbook workbook, boolean useSahredStringTable){
+    	this(workbook, DEFAULT_WINDOW_SIZE, useSahredStringTable);
+    }
+
+    /**
      * Constructs an workbook from an existing workbook.
      * <p>
      * When a new node is created via createRow() and the total number
@@ -138,9 +197,13 @@ 
      * </p>
      *
      * @param rowAccessWindowSize
+     * <p></p>
+     * Whether to use shared string table or not
+     * </p>
+     * @param useSahredStringTable 
      */
-    public SXSSFWorkbook(XSSFWorkbook workbook, int rowAccessWindowSize){
-    	this(workbook,rowAccessWindowSize, false);
+    public SXSSFWorkbook(XSSFWorkbook workbook, int rowAccessWindowSize, boolean useSahredStringTable){
+    	this(workbook,rowAccessWindowSize, false, useSahredStringTable);
     }
 
     /**
@@ -164,16 +227,22 @@ 
      * @param rowAccessWindowSize
      * @param compressTmpFiles whether to use gzip compression for temporary files
      */
-    public SXSSFWorkbook(XSSFWorkbook workbook, int rowAccessWindowSize, boolean compressTmpFiles){
+    public SXSSFWorkbook(XSSFWorkbook workbook, int rowAccessWindowSize, boolean compressTmpFiles, boolean useSahredStringTable){
     	setRandomAccessWindowSize(rowAccessWindowSize);
     	setCompressTempFiles(compressTmpFiles);
     	if (workbook == null)
     	{
     		_wb=new XSSFWorkbook();
+                if(useSahredStringTable){
+                    _sharedStringSource = _wb.getSharedStringSource();
+                }
     	}
     	else
     	{
     		_wb=workbook;
+                if(useSahredStringTable){
+                    _sharedStringSource = _wb.getSharedStringSource();
+                }
             for ( int i = 0; i < _wb.getNumberOfSheets(); i++ )
             {
                 XSSFSheet sheet = _wb.getSheetAt( i );
@@ -202,8 +271,38 @@ 
      * @param rowAccessWindowSize
      */
     public SXSSFWorkbook(int rowAccessWindowSize){
-    	this(null /*workbook*/, rowAccessWindowSize);
+    	this(null /*workbook*/, rowAccessWindowSize, false);
     }
+
+    /**
+     * Construct an empty workbook and specify the window for row access.
+     * <p>
+     * When a new node is created via createRow() and the total number
+     * of unflushed records would exceed the specified value, then the
+     * row with the lowest index value is flushed and cannot be accessed
+     * via getRow() anymore.
+     * </p>
+     * <p>
+     * A value of -1 indicates unlimited access. In this case all
+     * records that have not been flushed by a call to flush() are available
+     * for random access.
+     * <p>
+     * <p></p>
+     * A value of 0 is not allowed because it would flush any newly created row
+     * without having a chance to specify any cells.
+     * </p>
+     *
+     * @param rowAccessWindowSize
+     * <p></p>
+     * Whether to use shared string table or not
+     * </p>
+     * @param useSahredStringTable
+     *
+     *
+     */
+    public SXSSFWorkbook(int rowAccessWindowSize, boolean useSahredStringTable){
+    	this(null /*workbook*/, rowAccessWindowSize, useSahredStringTable);
+    }
     
     public int getRandomAccessWindowSize()
     {
@@ -236,9 +335,9 @@ 
 
     SheetDataWriter createSheetDataWriter() throws IOException {
         if(_compressTmpFiles) {
-            return new GZIPSheetDataWriter();
+            return new GZIPSheetDataWriter(_sharedStringSource);
         } else {
-            return new SheetDataWriter();
+            return new SheetDataWriter(_sharedStringSource);
         }
     }