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<!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V2.0//EN" "document-v20.dtd">

<document>
    <header>
        <title>Upgrading to POI 3.5, including converting existing HSSF Usermodel code to SS Usermodel (for XSSF and HSSF)</title>
        <authors>
            <person email="nick@apache.org" name="Nick Burch" id="NB"/>
        </authors>
    </header>
  <body>
<section><title>Things that have to be changed when upgrading to POI 3.5</title>
	<p>Wherever possible, we have tried to ensure that you can use your
     existing POI code with POI 3.5 without requiring any changes. However,
     Java doesn't always make that easy, and unfortunately there are a 
     few changes that may be required for some users.</p>
    <section><title>org.apache.poi.hssf.usermodel.HSSFFormulaEvaluator.CellValue</title>
       <p>Annoyingly, java will not let you access a static inner class via
        a child of the parent one. So, all references to
        <em>org.apache.poi.hssf.usermodel.HSSFFormulaEvaluator.CellValue</em>
        will need to be changed to
        <em>org.apache.poi.ss.usermodel.FormulaEvaluator.CellValue</em>
       </p>
    </section>
    <section><title>org.apache.poi.hssf.usermodel.HSSFRow.MissingCellPolicy</title>
       <p>Annoyingly, java will not let you access a static inner class via
        a child of the parent one. So, all references to
        <em>org.apache.poi.hssf.usermodel.HSSFRow.MissingCellPolicy</em>
        will need to be changed to
        <em>org.apache.poi.ss.usermodel.Row.MissingCellPolicy</em>
       </p>
    </section>
    <section><title>DDF and org.apache.poi.hssf.record.RecordFormatException</title>
       <p>Previously, record level errors within DDF would throw an
        exception from the hssf class hierarchy. Now, record level errors
        within DDF will throw a more general RecordFormatException,
        <em>org.apache.poi.util.RecordFormatException</em></p>
       <p>In addition, org.apache.poi.hssf.record.RecordFormatException
        has been changed to inherit from the new	
        <em>org.apache.poi.util.RecordFormatException</em>, so you may
        wish to change catches of the hssf version to the new util version.
       </p>
    </section>
  </section>
  <section><title>Converting existing HSSF Usermodel code to SS Usermodel (for XSSF and HSSF)</title>

        <section><title>Why change?</title>
            <p>If you have existing HSSF usermodel code that works just
            fine, and you don't want to use the new OOXML XSSF support,
            then you probably don't need to. Your existing HSSF only code
            will continue to work just fine.</p>
            <p>However, if you want to be able to work with both HSSF for
            your .xls files, and also XSSF for .xslx files, then you will
            need to make some slight tweaks to your code.</p>
        </section>
        <section><title>org.apache.poi.ss.usermodel</title>
           <p>The new SS usermodel (org.apache.poi.ss.usermodel) is very
           heavily based on the old HSSF usermodel 
           (org.apache.poi.hssf.usermodel). The main difference is that
           the package name and class names have been tweaked to remove
           HSSF from them. Otherwise, the new SS Usermodel interfaces 
           should provide the same functionality.</p>
        </section>
        <section><title>Constructors</title>
           <p>Calling the empty HSSFWorkbook remains as the way to 
           create a new, empty Workbook object. To open an existing
           Workbook, you should now call WorkbookFactory.create(inp).</p>
           <p>For all other cases when you would have called a
           Usermodel constructor, such as 'new HSSFRichTextString()' or
           'new HSSFDataFormat', you should instead use a CreationHelper.
           There's a method on the Workbook to get a CreationHelper, and
           the CreationHelper will then handle constructing new objects
           for you.</p>
		</section>
		<section><title>Other Code</title>
           <p>For all other code, generally change a reference from
            org.apache.poi.hssf.usermodel.HSSFFoo to a reference to
            org.apache.poi.ss.usermodel.Foo. Method signatures should
            otherwise remain the same, and it should all then work for
            both XSSF and HSSF.</p>
        </section>
  </section>
  <section><title>Worked Examples</title>
      <section><title>Old HSSF Code</title>
<source><![CDATA[
// import org.apache.poi.hssf.usermodel.*;

HSSFWorkbook wb = new HSSFWorkbook();
// create a new sheet
HSSFSheet s = wb.createSheet();
// declare a row object reference
HSSFRow r = null;
// declare a cell object reference
HSSFCell c = null;
// create 2 cell styles
HSSFCellStyle cs = wb.createCellStyle();
HSSFCellStyle cs2 = wb.createCellStyle();
HSSFDataFormat df = wb.createDataFormat();

// create 2 fonts objects
HSSFFont f = wb.createFont();
HSSFFont f2 = wb.createFont();

// Set font 1 to 12 point type, blue and bold
f.setFontHeightInPoints((short) 12);
f.setColor( HSSFColor.RED.index );
f.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);

// Set font 2 to 10 point type, red and bold
f2.setFontHeightInPoints((short) 10);
f2.setColor( HSSFFont.RED.index );
f2.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);

// Set cell style and formatting
cs.setFont(f);
cs.setDataFormat(df.getFormat("#,##0.0"));

// Set the other cell style and formatting
cs2.setBorderBottom(cs2.BORDER_THIN);
cs2.setDataFormat(HSSFDataFormat.getBuiltinFormat("text"));
cs2.setFont(f2);


// Define a few rows
for(short rownum = (short)0; rownum < 30; rownum++) {
	HSSFRow r = s.createRow(rownum);
	for(short cellnum = (short)0; cellnum < 10; cellnum += 2) {
		HSSFCell c = r.createCell(cellnum);
		HSSFCell c2 = r.createCell(cellnum+1);

		c.setCellValue((double)rownum + (cellnum/10));
		c2.setCellValue(new HSSFRichTextString("Hello! " + cellnum);
	}
}

// Save
FileOutputStream out = new FileOutputStream("workbook.xls");
wb.write(out);
out.close();
        ]]></source>
	</section>
	<section><title>New, generic SS Usermodel Code</title>
<source><![CDATA[
// import org.apache.poi.ss.usermodel.*;

Workbook[] wbs = new Workbook[] { new HSSFWorkbook(), new XSSFWorkbook() };
for(int i=0; i<wbs.length; i++) {
   Workbook wb = wbs[i];
   CreationHelper createHelper = wb.getCreationHelper();

   // create a new sheet
   Sheet s = wb.createSheet();
   // declare a row object reference
   Row r = null;
   // declare a cell object reference
   Cell c = null;
   // create 2 cell styles
   CellStyle cs = wb.createCellStyle();
   CellStyle cs2 = wb.createCellStyle();
   DataFormat df = wb.createDataFormat();

   // create 2 fonts objects
   Font f = wb.createFont();
   Font f2 = wb.createFont();

   // Set font 1 to 12 point type, blue and bold
   f.setFontHeightInPoints((short) 12);
   f.setColor( IndexedColors.RED.getIndex() );
   f.setBoldweight(Font.BOLDWEIGHT_BOLD);

   // Set font 2 to 10 point type, red and bold
   f2.setFontHeightInPoints((short) 10);
   f2.setColor( IndexedColors.RED.getIndex() );
   f2.setBoldweight(Font.BOLDWEIGHT_BOLD);

   // Set cell style and formatting
   cs.setFont(f);
   cs.setDataFormat(df.getFormat("#,##0.0"));

   // Set the other cell style and formatting
   cs2.setBorderBottom(cs2.BORDER_THIN);
   cs2.setDataFormat(df.getFormat("text"));
   cs2.setFont(f2);


   // Define a few rows
   for(int rownum = 0; rownum < 30; rownum++) {
	   Row r = s.createRow(rownum);
	   for(int cellnum = 0; cellnum < 10; cellnum += 2) {
		   Cell c = r.createCell(cellnum);
		   Cell c2 = r.createCell(cellnum+1);
   
		   c.setCellValue((double)rownum + (cellnum/10));
		   c2.setCellValue(
		         createHelper.createRichTextString("Hello! " + cellnum)
		   );
	   }
   }
   
   // Save
   String filename = "workbook.xls";
   if(wb instanceof XSSFWorkbook) {
     filename = filename + "x";
   }
 
   FileOutputStream out = new FileOutputStream(filename);
   wb.write(out);
   out.close();
}
        ]]></source>
	</section>
</section>
</body>
</document>
