Bug 51415 - Fixed Workbook.createSheet(sheetName) to truncate names longer than 31 characters

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1138819 13f79535-47bb-0310-9956-ffa450edef68

8 files changed, 295 insertions, 119 deletions

diff --git a/src/documentation/content/xdocs/spreadsheet/quick-guide.xml b/src/documentation/content/xdocs/spreadsheet/quick-guide.xml
index c83e46acce..adb7f607dc 100644
--- a/src/documentation/content/xdocs/spreadsheet/quick-guide.xml
+++ b/src/documentation/content/xdocs/spreadsheet/quick-guide.xml
@@ -92,14 +92,31 @@
                 <anchor id="NewSheet"/>
                 <section><title>New Sheet</title>
                     <source>
-    Workbook wb = new HSSFWorkbook();
-    //Workbook wb = new XSSFWorkbook();
+    Workbook wb = new HSSFWorkbook();  // or new XSSFWorkbook();
     Sheet sheet1 = wb.createSheet("new sheet");
     Sheet sheet2 = wb.createSheet("second sheet");
+
+    // Note that sheet name is Excel must not exceed 31 characters
+    // and must not contain any of the any of the following characters:
+    // 0x0000
+    // 0x0003
+    // colon (:)
+    // backslash (\)
+    // asterisk (*)
+    // question mark (?)
+    // forward slash (/)
+    // opening square bracket ([)
+    // closing square bracket (])
+
+    // You can use org.apache.poi.ss.util.WorkbookUtil#createSafeSheetName(String nameProposal)}
+    // for a safe way to create valid names, this utility replaces invalid characters with a space (' ')
+    String safeName = WorkbookUtil.createSafeSheetName("[O'Brien's sales*?]"); // returns " O'Brien's sales   "
+    Sheet sheet3 = wb.createSheet(safeName);
+
     FileOutputStream fileOut = new FileOutputStream("workbook.xls");
     wb.write(fileOut);
     fileOut.close();
-                    </source>
+                     </source>
                 </section>
                 <anchor id="CreateCells"/>
                 <section><title>Creating Cells</title>
@@ -271,15 +288,15 @@
                 so using Java 1.5 you can simply take advantage
                 of the built in "foreach" support - see below.</p>
 				<source>
-	Sheet sheet = wb.getSheetAt(0);
-	for (Iterator&lt;Row&gt; rit = sheet.rowIterator(); rit.hasNext(); ) {
-		Row row = rit.next();
-		for (Iterator&lt;Cell&gt; cit = row.cellIterator(); cit.hasNext(); ) {
-			Cell cell = cit.next();
-			// Do something here
-		}
-	}
-				</source>
+    sheet sheet = wb.getsheetat(0);
+    for (iterator&lt;row&gt; rit = sheet.rowiterator(); rit.hasnext(); ) {
+      row row = rit.next();
+      for (iterator&lt;cell&gt; cit = row.celliterator(); cit.hasnext(); ) {
+        cell cell = cit.next();
+        // do something here
+      }
+    }
+        </source>
                 </section>
                 <section><title>Iterate over rows and cells using Java 1.5 foreach loops</title>
 				<p>Sometimes, you'd like to just iterate over all the rows in
@@ -293,12 +310,12 @@
 				the cells, and for Sheet gives the 
 				<em>rowIterator()</em> to iterator over all the rows.</p>
 				<source>
-	Sheet sheet = wb.getSheetAt(0);
-	for (Row row : sheet) {
-		for (Cell cell : row) {
-			// Do something here
-		}
-	}
+    Sheet sheet = wb.getSheetAt(0);
+    for (Row row : sheet) {
+      for (Cell cell : row) {
+        // Do something here
+      }
+    }
 				</source>
                 </section>
 
@@ -314,37 +331,37 @@
                     in one sheet, print out the cell's reference
                     (eg A3), and then the cell's contents.</p>
 				<source>
-// import org.apache.poi.ss.usermodel.*;
-
-Sheet sheet1 = wb.getSheetAt(0);
-for (Row row : sheet1) {
-	for (Cell cell : row) {
-		CellReference cellRef = new CellReference(row.getRowNum(), cell.getCellNum());
-		System.out.print(cellRef.formatAsString());
-		System.out.print(" - ");
-		
-		switch(cell.getCellType()) {
-      case Cell.CELL_TYPE_STRING:
-        System.out.println(cell.getRichStringCellValue().getString());
-        break;
-      case Cell.CELL_TYPE_NUMERIC:
-        if(DateUtil.isCellDateFormatted(cell)) {
-          System.out.println(cell.getDateCellValue());
-        } else {
-          System.out.println(cell.getNumericCellValue());
+    // import org.apache.poi.ss.usermodel.*;
+
+    Sheet sheet1 = wb.getSheetAt(0);
+    for (Row row : sheet1) {
+        for (Cell cell : row) {
+            CellReference cellRef = new CellReference(row.getRowNum(), cell.getCellNum());
+            System.out.print(cellRef.formatAsString());
+            System.out.print(" - ");
+
+            switch (cell.getCellType()) {
+                case Cell.CELL_TYPE_STRING:
+                    System.out.println(cell.getRichStringCellValue().getString());
+                    break;
+                case Cell.CELL_TYPE_NUMERIC:
+                    if (DateUtil.isCellDateFormatted(cell)) {
+                        System.out.println(cell.getDateCellValue());
+                    } else {
+                        System.out.println(cell.getNumericCellValue());
+                    }
+                    break;
+                case Cell.CELL_TYPE_BOOLEAN:
+                    System.out.println(cell.getBooleanCellValue());
+                    break;
+                case Cell.CELL_TYPE_FORMULA:
+                    System.out.println(cell.getCellFormula());
+                    break;
+                default:
+                    System.out.println();
+            }
         }
-        break;
-      case Cell.CELL_TYPE_BOOLEAN:
-        System.out.println(cell.getBooleanCellValue());
-        break;
-      case Cell.CELL_TYPE_FORMULA:
-        System.out.println(cell.getCellFormula());
-        break;
-      default:
-        System.out.println();
-		}
-	}
-}
+    }
 				</source>
                 </section>
 
@@ -353,13 +370,13 @@ for (Row row : sheet1) {
 					<p>For most text extraction requirements, the standard
 					ExcelExtractor class should provide all you need.</p>
 					<source>
-	InputStream inp = new FileInputStream("workbook.xls");
-	HSSFWorkbook wb = new HSSFWorkbook(new POIFSFileSystem(inp));
-	ExcelExtractor extractor = new ExcelExtractor(wb);
+    InputStream inp = new FileInputStream("workbook.xls");
+    HSSFWorkbook wb = new HSSFWorkbook(new POIFSFileSystem(inp));
+    ExcelExtractor extractor = new ExcelExtractor(wb);
 
-	extractor.setFormulasNotResults(true);
-	extractor.setIncludeSheetNames(false);
-	String text = extractor.getText();
+    extractor.setFormulasNotResults(true);
+    extractor.setIncludeSheetNames(false);
+    String text = extractor.getText();
 					</source>
 					<p>For very fancy text extraction, XLS to CSV etc, 
 					take a look at
@@ -458,29 +475,29 @@ Examples:
 </p>
 <p><strong>Wrong:</strong></p>
 <source>
-        for (int i = 0; i &lt; 10000; i++) {
-            Row row = sheet.createRow(i);
-            Cell cell = row.createCell((short) 0);
-
-            CellStyle style = workbook.createCellStyle();
-            Font font = workbook.createFont();
-            font.setBoldweight(Font.BOLDWEIGHT_BOLD);
-            style.setFont(font);
-            cell.setCellStyle(style);
-        }
-</source>
-<p><strong>Correct:</strong></p>
-<source>
+    for (int i = 0; i &lt; 10000; i++) {
+        Row row = sheet.createRow(i);
+        Cell cell = row.createCell((short) 0);
 
         CellStyle style = workbook.createCellStyle();
         Font font = workbook.createFont();
         font.setBoldweight(Font.BOLDWEIGHT_BOLD);
         style.setFont(font);
-        for (int i = 0; i &lt; 10000; i++) {
-            Row row = sheet.createRow(i);
-            Cell cell = row.createCell((short) 0);
-            cell.setCellStyle(style);
-        }
+        cell.setCellStyle(style);
+    }
+</source>
+<p><strong>Correct:</strong></p>
+<source>
+
+    CellStyle style = workbook.createCellStyle();
+    Font font = workbook.createFont();
+    font.setBoldweight(Font.BOLDWEIGHT_BOLD);
+    style.setFont(font);
+    for (int i = 0; i &lt; 10000; i++) {
+        Row row = sheet.createRow(i);
+        Cell cell = row.createCell((short) 0);
+        cell.setCellStyle(style);
+    }
 </source>
   
                 </section>
@@ -1390,7 +1407,7 @@ Examples:
       If your workbook has many formulas then it is a good idea to evaluate them before auto-sizing.
     </p>
         <warning>
-    To calculate column width HSSFSheet.autoSizeColumn uses Java2D classes
+    To calculate column width Sheet.autoSizeColumn uses Java2D classes
     that throw exception if graphical environment is not available. In case if graphical environment
     is not available, you must tell Java that you are running in headless mode and
     set the following system property: <code> java.awt.headless=true </code>.
@@ -1692,7 +1709,6 @@ Examples:
     };
 
     sheetCF.addConditionalFormatting(regions, cfRules);
-    sheetCF.addConditionalFormatting(regions, cfRules);
        </source>
      </section>  
     </body>
diff --git a/src/documentation/content/xdocs/status.xml b/src/documentation/content/xdocs/status.xml
index f1b78a6ba7..614b001f25 100644
--- a/src/documentation/content/xdocs/status.xml
+++ b/src/documentation/content/xdocs/status.xml
@@ -34,6 +34,7 @@
 
     <changes>
         <release version="3.8-beta4" date="2011-??-??">
+           <action dev="poi-developers" type="fix">51415 - Fixed Workbook.createSheet(sheetName) to truncate names longer than 31 characters</action>
            <action dev="poi-developers" type="fix">51332 - Fixed internal IDs of shapes generated by HSSFPatriarch when there are more than 1023 drawing objects </action>
            <action dev="poi-developers" type="fix">48408 - Improved documentation for Sheet.setColumnWidth </action>
            <action dev="poi-developers" type="add">51390 - Added handling of additional properties to HWPF ParagraphSprmCompressor</action>
diff --git a/src/java/org/apache/poi/hssf/model/InternalWorkbook.java b/src/java/org/apache/poi/hssf/model/InternalWorkbook.java
index 62796a62f2..e781675efa 100644
--- a/src/java/org/apache/poi/hssf/model/InternalWorkbook.java
+++ b/src/java/org/apache/poi/hssf/model/InternalWorkbook.java
@@ -89,6 +89,7 @@ import org.apache.poi.hssf.util.HSSFColor;
 import org.apache.poi.ss.formula.EvaluationWorkbook.ExternalName;
 import org.apache.poi.ss.formula.EvaluationWorkbook.ExternalSheet;
 import org.apache.poi.ss.usermodel.BuiltinFormats;
+import org.apache.poi.ss.util.WorkbookUtil;
 import org.apache.poi.util.Internal;
 import org.apache.poi.util.POILogFactory;
 import org.apache.poi.util.POILogger;
@@ -579,6 +580,10 @@ public final class InternalWorkbook {
      */
     public void setSheetName(int sheetnum, String sheetname) {
         checkSheets(sheetnum);
+
+        // YK: Mimic Excel and silently truncate sheet names longer than 31 characters
+        if(sheetname.length() > 31) sheetname = sheetname.substring(0, 31);
+
         BoundSheetRecord sheet = boundsheets.get(sheetnum);
         sheet.setSheetname(sheetname);
     }
diff --git a/src/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java b/src/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
index a0007fcee7..863e160b30 100644
--- a/src/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
+++ b/src/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
@@ -543,15 +543,20 @@ public final class HSSFWorkbook extends POIDocument implements org.apache.poi.ss
     }
 
     /**
-     * Sets the sheet name.
-     * Will throw IllegalArgumentException if the name is duplicated or contains /\?*[]
-     * Note - Excel allows sheet names up to 31 chars in length but other applications allow more.
-     * Excel does not crash with names longer than 31 chars, but silently truncates such names to
-     * 31 chars.  POI enforces uniqueness on the first 31 chars.
+     * Set the sheet name.
      *
-     * @param sheetIx number (0 based)
+     * @param sheet number (0 based)
+     * @throws IllegalArgumentException if the name is null or invalid
+     *  or workbook already contains a sheet with this name
+     * @see {@link #createSheet(String)}
+     * @see {@link org.apache.poi.ss.util.WorkbookUtil#createSafeSheetName(String nameProposal)}
+     *      for a safe way to create valid names
      */
     public void setSheetName(int sheetIx, String name) {
+        if (name == null) {
+            throw new IllegalArgumentException("sheetName must not be null");
+        }
+
         if (workbook.doesContainsSheetName(name, sheetIx)) {
             throw new IllegalArgumentException("The workbook already contains a sheet with this name");
         }
@@ -757,20 +762,55 @@ public final class HSSFWorkbook extends POIDocument implements org.apache.poi.ss
     }
 
     /**
-     * create an HSSFSheet for this HSSFWorkbook, adds it to the sheets and
-     * returns the high level representation. Use this to create new sheets.
+     * Create a new sheet for this Workbook and return the high level representation.
+     * Use this to create new sheets.
      *
-     * @param sheetname the name for the new sheet. Note - certain length limits
-     * apply. See {@link #setSheetName(int, String)}.
-     * @see org.apache.poi.ss.util.WorkbookUtil#createSafeSheetName(String nameProposal)
-     *  for a safe way to create valid names
-     * @return HSSFSheet representing the new sheet.
-     * @throws IllegalArgumentException
-     *             if there is already a sheet present with a case-insensitive
-     *             match for the specified name.
+     * <p>
+     *     Note that Excel allows sheet names up to 31 chars in length but other applications
+     *     (such as OpenOffice) allow more. Some versions of Excel crash with names longer than 31 chars,
+     *     others - truncate such names to 31 character.
+     * </p>
+     * <p>
+     *     POI's SpreadsheetAPI silently truncates the input argument to 31 characters.
+     *     Example:
+     *
+     *     <pre><code>
+     *     Sheet sheet = workbook.createSheet("My very long sheet name which is longer than 31 chars"); // will be truncated
+     *     assert 31 == sheet.getSheetName().length();
+     *     assert "My very long sheet name which i" == sheet.getSheetName();
+     *     </code></pre>
+     * </p>
+     *
+     * Except the 31-character constraint, Excel applies some other rules:
+     * <p>
+     * Sheet name MUST be unique in the workbook and MUST NOT contain the any of the following characters:
+     * <ul>
+     * <li> 0x0000 </li>
+     * <li> 0x0003 </li>
+     * <li> colon (:) </li>
+     * <li> backslash (\) </li>
+     * <li> asterisk (*) </li>
+     * <li> question mark (?) </li>
+     * <li> forward slash (/) </li>
+     * <li> opening square bracket ([) </li>
+     * <li> closing square bracket (]) </li>
+     * </ul>
+     * The string MUST NOT begin or end with the single quote (') character.
+     * </p>
+     *
+     * @param sheetname  sheetname to set for the sheet.
+     * @return Sheet representing the new sheet.
+     * @throws IllegalArgumentException if the name is null or invalid
+     *  or workbook already contains a sheet with this name
+     * @see {@link org.apache.poi.ss.util.WorkbookUtil#createSafeSheetName(String nameProposal)}
+     *      for a safe way to create valid names
      */
     public HSSFSheet createSheet(String sheetname)
     {
+        if (sheetname == null) {
+            throw new IllegalArgumentException("sheetName must not be null");
+        }
+
         if (workbook.doesContainsSheetName( sheetname, _sheets.size() ))
             throw new IllegalArgumentException( "The workbook already contains a sheet of this name" );
 
diff --git a/src/java/org/apache/poi/ss/usermodel/Workbook.java b/src/java/org/apache/poi/ss/usermodel/Workbook.java
index 03a349d3fa..9312eba797 100644
--- a/src/java/org/apache/poi/ss/usermodel/Workbook.java
+++ b/src/java/org/apache/poi/ss/usermodel/Workbook.java
@@ -131,12 +131,16 @@ public interface Workbook {
      * Set the sheet name.
      *
      * @param sheet number (0 based)
-     * @throws IllegalArgumentException if the name is greater than 31 chars or contains <code>/\?*[]</code>
+     * @throws IllegalArgumentException if the name is null or invalid
+     *  or workbook already contains a sheet with this name
+     * @see {@link #createSheet(String)}
+     * @see {@link org.apache.poi.ss.util.WorkbookUtil#createSafeSheetName(String nameProposal)}
+     *      for a safe way to create valid names
      */
     void setSheetName(int sheet, String name);
 
     /**
-     * Set the sheet name
+     * Get the sheet name
      *
      * @param sheet sheet number (0 based)
      * @return Sheet name
@@ -168,12 +172,48 @@ public interface Workbook {
     Sheet createSheet();
 
     /**
-     * Create an Sheet for this Workbook, adds it to the sheets and returns
-     * the high level representation.  Use this to create new sheets.
+     * Create a new sheet for this Workbook and return the high level representation.
+     * Use this to create new sheets.
+     *
+     * <p>
+     *     Note that Excel allows sheet names up to 31 chars in length but other applications
+     *     (such as OpenOffice) allow more. Some versions of Excel crash with names longer than 31 chars,
+     *     others - truncate such names to 31 character.
+     * </p>
+     * <p>
+     *     POI's SpreadsheetAPI silently truncates the input argument to 31 characters.
+     *     Example:
+     *
+     *     <pre><code>
+     *     Sheet sheet = workbook.createSheet("My very long sheet name which is longer than 31 chars"); // will be truncated
+     *     assert 31 == sheet.getSheetName().length();
+     *     assert "My very long sheet name which i" == sheet.getSheetName();
+     *     </code></pre>
+     * </p>
+     *
+     * Except the 31-character constraint, Excel applies some other rules:
+     * <p>
+     * Sheet name MUST be unique in the workbook and MUST NOT contain the any of the following characters:
+     * <ul>
+     * <li> 0x0000 </li>
+     * <li> 0x0003 </li>
+     * <li> colon (:) </li>
+     * <li> backslash (\) </li>
+     * <li> asterisk (*) </li>
+     * <li> question mark (?) </li>
+     * <li> forward slash (/) </li>
+     * <li> opening square bracket ([) </li>
+     * <li> closing square bracket (]) </li>
+     * </ul>
+     * The string MUST NOT begin or end with the single quote (') character.
+     * </p>
      *
      * @param sheetname  sheetname to set for the sheet.
      * @return Sheet representing the new sheet.
-     * @throws IllegalArgumentException if the name is greater than 31 chars or contains <code>/\?*[]</code>
+     * @throws IllegalArgumentException if the name is null or invalid
+     *  or workbook already contains a sheet with this name
+     * @see {@link org.apache.poi.ss.util.WorkbookUtil#createSafeSheetName(String nameProposal)}
+     *      for a safe way to create valid names
      */
     Sheet createSheet(String sheetname);
 
diff --git a/src/java/org/apache/poi/ss/util/WorkbookUtil.java b/src/java/org/apache/poi/ss/util/WorkbookUtil.java
index 8ab44b9ce4..767e1327e2 100644
--- a/src/java/org/apache/poi/ss/util/WorkbookUtil.java
+++ b/src/java/org/apache/poi/ss/util/WorkbookUtil.java
@@ -104,9 +104,11 @@ public class WorkbookUtil {
             throw new IllegalArgumentException("sheetName must not be null");
         }
         int len = sheetName.length();
-        if (len < 1) {
-            throw new IllegalArgumentException("sheetName must not be empty string");
+        if (len < 1 || len > 31) {
+            throw new IllegalArgumentException("sheetName '" + sheetName
+                    + "' is invalid - character count MUST be greater than or equal to 1 and less than or equal to 31");
         }
+
         for (int i=0; i<len; i++) {
             char ch = sheetName.charAt(i);
             switch (ch) {
diff --git a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFWorkbook.java b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFWorkbook.java
index f4512914df..d7dd953f2a 100644
--- a/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFWorkbook.java
+++ b/src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFWorkbook.java
@@ -494,17 +494,61 @@ public class XSSFWorkbook extends POIXMLDocument implements Workbook, Iterable<X
     }
 
     /**
-     * Create an XSSFSheet for this workbook, adds it to the sheets and returns
-     * the high level representation.  Use this to create new sheets.
+     * Create a new sheet for this Workbook and return the high level representation.
+     * Use this to create new sheets.
      *
-     * @param sheetname  sheetname to set for the sheet, can't be duplicate, greater than 31 chars or contain /\?*[]
-     * @return XSSFSheet representing the new sheet.
-     * @throws IllegalArgumentException if the sheetname is invalid or the workbook already contains a sheet of this name
+     * <p>
+     *     Note that Excel allows sheet names up to 31 chars in length but other applications
+     *     (such as OpenOffice) allow more. Some versions of Excel crash with names longer than 31 chars,
+     *     others - truncate such names to 31 character.
+     * </p>
+     * <p>
+     *     POI's SpreadsheetAPI silently truncates the input argument to 31 characters.
+     *     Example:
+     *
+     *     <pre><code>
+     *     Sheet sheet = workbook.createSheet("My very long sheet name which is longer than 31 chars"); // will be truncated
+     *     assert 31 == sheet.getSheetName().length();
+     *     assert "My very long sheet name which i" == sheet.getSheetName();
+     *     </code></pre>
+     * </p>
+     *
+     * Except the 31-character constraint, Excel applies some other rules:
+     * <p>
+     * Sheet name MUST be unique in the workbook and MUST NOT contain the any of the following characters:
+     * <ul>
+     * <li> 0x0000 </li>
+     * <li> 0x0003 </li>
+     * <li> colon (:) </li>
+     * <li> backslash (\) </li>
+     * <li> asterisk (*) </li>
+     * <li> question mark (?) </li>
+     * <li> forward slash (/) </li>
+     * <li> opening square bracket ([) </li>
+     * <li> closing square bracket (]) </li>
+     * </ul>
+     * The string MUST NOT begin or end with the single quote (') character.
+     * </p>
+     *
+     * @param sheetname  sheetname to set for the sheet.
+     * @return Sheet representing the new sheet.
+     * @throws IllegalArgumentException if the name is null or invalid
+     *  or workbook already contains a sheet with this name
+     * @see {@link org.apache.poi.ss.util.WorkbookUtil#createSafeSheetName(String nameProposal)}
+     *      for a safe way to create valid names
      */
     public XSSFSheet createSheet(String sheetname) {
+        if (sheetname == null) {
+            throw new IllegalArgumentException("sheetName must not be null");
+        }
+
         if (containsSheet( sheetname, sheets.size() ))
                throw new IllegalArgumentException( "The workbook already contains a sheet of this name");
 
+        // YK: Mimic Excel and silently truncate sheet names longer than 31 characters
+        if(sheetname.length() > 31) sheetname = sheetname.substring(0, 31);
+        WorkbookUtil.validateSheetName(sheetname);
+
         CTSheet sheet = addSheet(sheetname);
 
         int sheetNumber = 1;
@@ -525,8 +569,6 @@ public class XSSFWorkbook extends POIXMLDocument implements Workbook, Iterable<X
     }
 
     private CTSheet addSheet(String sheetname) {
-        WorkbookUtil.validateSheetName(sheetname);
-
         CTSheet sheet = workbook.getSheets().addNewSheet();
         sheet.setName(sheetname);
         return sheet;
@@ -1115,21 +1157,29 @@ public class XSSFWorkbook extends POIXMLDocument implements Workbook, Iterable<X
 
     /**
      * Set the sheet name.
-     * Will throw IllegalArgumentException if the name is greater than 31 chars
-     * or contains /\?*[]
      *
-     * @param sheetIndex number (0 based)
-     */
-    public void setSheetName(int sheetIndex, String name) {
+     * @param sheetIndex sheet number (0 based)
+     * @param sheetname  the new sheet name
+     * @throws IllegalArgumentException if the name is null or invalid
+     *  or workbook already contains a sheet with this name
+     * @see {@link #createSheet(String)}
+     * @see {@link org.apache.poi.ss.util.WorkbookUtil#createSafeSheetName(String nameProposal)}
+     *      for a safe way to create valid names
+     */
+    public void setSheetName(int sheetIndex, String sheetname) {
         validateSheetIndex(sheetIndex);
-        WorkbookUtil.validateSheetName(name);
-        if (containsSheet(name, sheetIndex ))
+
+        // YK: Mimic Excel and silently truncate sheet names longer than 31 characters
+        if(sheetname != null && sheetname.length() > 31) sheetname = sheetname.substring(0, 31);
+        WorkbookUtil.validateSheetName(sheetname);
+
+        if (containsSheet(sheetname, sheetIndex ))
             throw new IllegalArgumentException( "The workbook already contains a sheet of this name" );
 
         XSSFFormulaUtils utils = new XSSFFormulaUtils(this);
-        utils.updateSheetName(sheetIndex, name);
+        utils.updateSheetName(sheetIndex, sheetname);
 
-        workbook.getSheets().getSheetArray(sheetIndex).setName(name);
+        workbook.getSheets().getSheetArray(sheetIndex).setName(sheetname);
     }
 
     /**
diff --git a/src/testcases/org/apache/poi/ss/usermodel/BaseTestWorkbook.java b/src/testcases/org/apache/poi/ss/usermodel/BaseTestWorkbook.java
index a4a8d29cc8..9ba714c748 100644
--- a/src/testcases/org/apache/poi/ss/usermodel/BaseTestWorkbook.java
+++ b/src/testcases/org/apache/poi/ss/usermodel/BaseTestWorkbook.java
@@ -99,6 +99,22 @@ public abstract class BaseTestWorkbook extends TestCase {
             // expected during successful test
         }
 
+        //try to assign an invalid name to the 2nd sheet
+        try {
+            wb.createSheet(null);
+            fail("should have thrown exceptiuon due to invalid sheet name");
+        } catch (IllegalArgumentException e) {
+            // expected during successful test
+        }
+
+        try {
+            wb.setSheetName(2, null);
+
+            fail("should have thrown exceptiuon due to invalid sheet name");
+        } catch (IllegalArgumentException e) {
+            // expected during successful test
+        }
+
         //check
         assertEquals(0, wb.getSheetIndex("sheet0"));
         assertEquals(1, wb.getSheetIndex("sheet1"));
@@ -129,9 +145,14 @@ public abstract class BaseTestWorkbook extends TestCase {
         Workbook wb = _testDataProvider.createWorkbook();
 
         String sheetName1 = "My very long sheet name which is longer than 31 chars";
+        String truncatedSheetName1 = sheetName1.substring(0, 31);
         Sheet sh1 = wb.createSheet(sheetName1);
-        assertEquals(sheetName1, sh1.getSheetName());
-        assertSame(sh1, wb.getSheet(sheetName1));
+        assertEquals(truncatedSheetName1, sh1.getSheetName());
+        assertSame(sh1, wb.getSheet(truncatedSheetName1));
+        // now via wb.setSheetName
+        wb.setSheetName(0, sheetName1);
+        assertEquals(truncatedSheetName1, sh1.getSheetName());
+        assertSame(sh1, wb.getSheet(truncatedSheetName1));
 
         String sheetName2 = "My very long sheet name which is longer than 31 chars " +
                 "and sheetName2.substring(0, 31) == sheetName1.substring(0, 31)";
@@ -144,15 +165,16 @@ public abstract class BaseTestWorkbook extends TestCase {
         }
 
         String sheetName3 = "POI allows creating sheets with names longer than 31 characters";
+        String truncatedSheetName3 = sheetName3.substring(0, 31);
         Sheet sh3 = wb.createSheet(sheetName3);
-        assertEquals(sheetName3, sh3.getSheetName());
-        assertSame(sh3, wb.getSheet(sheetName3));
+        assertEquals(truncatedSheetName3, sh3.getSheetName());
+        assertSame(sh3, wb.getSheet(truncatedSheetName3));
 
         //serialize and read again
         wb = _testDataProvider.writeOutAndReadBack(wb);
         assertEquals(2, wb.getNumberOfSheets());
-        assertEquals(0, wb.getSheetIndex(sheetName1));
-        assertEquals(1, wb.getSheetIndex(sheetName3));
+        assertEquals(0, wb.getSheetIndex(truncatedSheetName1));
+        assertEquals(1, wb.getSheetIndex(truncatedSheetName3));
     }
 
     public void testRemoveSheetAt() {