Extend the support for specifying a policy to HSSF on missing / blank cells when fetching, to be able to specify the policy at the HSSFWorkbook level

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@659525 13f79535-47bb-0310-9956-ffa450edef68

src/documentation/content/xdocs/changes.xml

@@ -37,9 +37,10 @@
 
 		<!-- Don't forget to update status.xml too! -->
         <release version="3.1-final" date="2008-06-??">
-           <action dev="POI-DEVELOPERS" type="add">45025 - improved FormulaParser parse error messages</action>
+           <action dev="POI-DEVELOPERS" type="add">Extend the support for specifying a policy to HSSF on missing / blank cells when fetching, to be able to specify the policy at the HSSFWorkbook level</action>
-           <action dev="POI-DEVELOPERS" type="add">45046 - allowed EXTERNALBOOK(0x01AE) to be optional in the LinkTable</action>
+           <action dev="POI-DEVELOPERS" type="fix">45025 - improved FormulaParser parse error messages</action>
-           <action dev="POI-DEVELOPERS" type="add">45066 - fixed sheet encoding size mismatch problems</action>
+           <action dev="POI-DEVELOPERS" type="fix">45046 - allowed EXTERNALBOOK(0x01AE) to be optional in the LinkTable</action>
+           <action dev="POI-DEVELOPERS" type="fix">45066 - fixed sheet encoding size mismatch problems</action>
            <action dev="POI-DEVELOPERS" type="add">45003 - Support embeded HDGF visio documents</action>
            <action dev="POI-DEVELOPERS" type="fix">45001 - Partial fix for HWPF Range.insertBefore() and Range.delete() with unicode characters</action>
            <action dev="POI-DEVELOPERS" type="fix">44977 - Support for AM/PM in excel date formats</action>

src/documentation/content/xdocs/status.xml

@@ -34,9 +34,10 @@
 	<!-- Don't forget to update changes.xml too! -->
     <changes>
         <release version="3.1-final" date="2008-06-??">
-           <action dev="POI-DEVELOPERS" type="add">45025 - improved FormulaParser parse error messages</action>
+           <action dev="POI-DEVELOPERS" type="add">Extend the support for specifying a policy to HSSF on missing / blank cells when fetching, to be able to specify the policy at the HSSFWorkbook level</action>
-           <action dev="POI-DEVELOPERS" type="add">45046 - allowed EXTERNALBOOK(0x01AE) to be optional in the LinkTable</action>
+           <action dev="POI-DEVELOPERS" type="fix">45025 - improved FormulaParser parse error messages</action>
-           <action dev="POI-DEVELOPERS" type="add">45066 - fixed sheet encoding size mismatch problems</action>
+           <action dev="POI-DEVELOPERS" type="fix">45046 - allowed EXTERNALBOOK(0x01AE) to be optional in the LinkTable</action>
+           <action dev="POI-DEVELOPERS" type="fix">45066 - fixed sheet encoding size mismatch problems</action>
            <action dev="POI-DEVELOPERS" type="add">45003 - Support embeded HDGF visio documents</action>
            <action dev="POI-DEVELOPERS" type="fix">45001 - Partial fix for HWPF Range.insertBefore() and Range.delete() with unicode characters</action>
            <action dev="POI-DEVELOPERS" type="fix">44977 - Support for AM/PM in excel date formats</action>

src/java/org/apache/poi/hssf/usermodel/HSSFRow.java

@@ -276,8 +276,23 @@ public final class HSSFRow implements Comparable {
 
     /**
      * Get the hssfcell representing a given column (logical cell)
-     *  0-based.  If you ask for a cell that is not defined....
+     *  0-based. If you ask for a cell that is not defined, then
      *  you get a null.
+     * This is the basic call, with no policies applied
+     *
+     * @param cellnum  0 based column number
+     * @return HSSFCell representing that column or null if undefined.
+     */
+    private HSSFCell retrieveCell(int cellnum) {
+        if(cellnum<0||cellnum>=cells.length) return null;
+        return cells[cellnum];
+    }
+    
+    /**
+     * Get the hssfcell representing a given column (logical cell)
+     *  0-based.  If you ask for a cell that is not defined then
+     *  you get a null, unless you have set a different
+     *  {@link MissingCellPolicy} on the base workbook.
      * Short method signature provided to retain binary
      *  compatibility.
      *
@@ -288,17 +303,18 @@ public final class HSSFRow implements Comparable {
         int ushortCellNum = cellnum & 0x0000FFFF; // avoid sign extension
         return getCell(ushortCellNum);
     }
+    
     /**
      * Get the hssfcell representing a given column (logical cell)
-     *  0-based.  If you ask for a cell that is not defined....
+     *  0-based.  If you ask for a cell that is not defined then
-     *  you get a null.
+     *  you get a null, unless you have set a different
+     *  {@link MissingCellPolicy} on the base workbook.
      *
      * @param cellnum  0 based column number
      * @return HSSFCell representing that column or null if undefined.
      */
     public HSSFCell getCell(int cellnum) {
-        if(cellnum<0||cellnum>=cells.length) return null;
+    	return getCell(cellnum, book.getMissingCellPolicy());
-        return cells[cellnum];
     }
     
     /**
@@ -311,7 +327,7 @@ public final class HSSFRow implements Comparable {
      * @return representing that column or null if undefined + policy allows.
      */
     public HSSFCell getCell(int cellnum, MissingCellPolicy policy) {
-    	HSSFCell cell = getCell(cellnum);
+    	HSSFCell cell = retrieveCell(cellnum);
     	if(policy == RETURN_NULL_AND_BLANK) {
     		return cell;
     	}
@@ -335,7 +351,6 @@ public final class HSSFRow implements Comparable {
      * get the number of the first cell contained in this row.
      * @return short representing the first logical cell in the row, or -1 if the row does not contain any cells.
      */
-
     public short getFirstCellNum()
     {
         if (getPhysicalNumberOfCells() == 0)

src/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java

@@ -29,6 +29,7 @@ import org.apache.poi.hssf.record.*;
 import org.apache.poi.hssf.record.formula.Area3DPtg;
 import org.apache.poi.hssf.record.formula.MemFuncPtg;
 import org.apache.poi.hssf.record.formula.UnionPtg;
+import org.apache.poi.hssf.usermodel.HSSFRow.MissingCellPolicy;
 import org.apache.poi.hssf.util.CellReference;
 import org.apache.poi.hssf.util.SheetReferences;
 import org.apache.poi.poifs.filesystem.*;
@@ -103,6 +104,13 @@ public class HSSFWorkbook extends POIDocument
      */
     private HSSFDataFormat formatter;
     
+    /**
+     * The policy to apply in the event of missing or
+     *  blank cells when fetching from a row.
+     * See {@link MissingCellPolicy}
+     */
+    private MissingCellPolicy missingCellPolicy = HSSFRow.RETURN_NULL_AND_BLANK;
+
 
     /** Extended windows meta file */
     public static final int PICTURE_TYPE_EMF = 2;
@@ -345,6 +353,26 @@ public class HSSFWorkbook extends POIDocument
              log.log(POILogger.DEBUG, "convertLabelRecords exit");
      }
 
+	/**
+	 * Retrieves the current policy on what to do when
+	 *  getting missing or blank cells from a row.
+	 * The default is to return blank and null cells.
+	 *  {@link MissingCellPolicy}
+	 */
+	public MissingCellPolicy getMissingCellPolicy() {
+		return missingCellPolicy;
+	}
+
+	/**
+	 * Sets the policy on what to do when
+	 *  getting missing or blank cells from a row.
+	 * This will then apply to all calls to 
+	 *  {@link HSSFRow.getCell()}. See
+	 *  {@link MissingCellPolicy}
+	 */
+	public void setMissingCellPolicy(MissingCellPolicy missingCellPolicy) {
+		this.missingCellPolicy = missingCellPolicy;
+	}
 
 	/**
      * sets the order of appearance for a given sheet.

src/testcases/org/apache/poi/hssf/usermodel/TestHSSFRow.java

@@ -20,6 +20,7 @@ package org.apache.poi.hssf.usermodel;
 import junit.framework.TestCase;
 
 import org.apache.poi.hssf.HSSFTestDataSamples;
+import org.apache.poi.hssf.usermodel.HSSFRow.MissingCellPolicy;
 
 /**
  * Test HSSFRow is okay.
@@ -224,7 +225,7 @@ public final class TestHSSFRow extends TestCase {
         row.createCell((short)4, HSSFCell.CELL_TYPE_BLANK);
         row.createCell((short)5).setCellValue(4);
         
-        // First up, no policy
+        // First up, no policy given, uses default
         assertEquals(HSSFCell.CELL_TYPE_STRING,  row.getCell(0).getCellType());
         assertEquals(HSSFCell.CELL_TYPE_NUMERIC, row.getCell(1).getCellType());
         assertEquals(null, row.getCell(2));
@@ -263,5 +264,17 @@ public final class TestHSSFRow extends TestCase {
         assertEquals((short)3, row.getCell(3, HSSFRow.CREATE_NULL_AS_BLANK).getCellNum());
         assertEquals((short)4, row.getCell(4, HSSFRow.CREATE_NULL_AS_BLANK).getCellNum());
         assertEquals((short)5, row.getCell(5, HSSFRow.CREATE_NULL_AS_BLANK).getCellNum());
+        
+        
+        // Now change the cell policy on the workbook, check
+        //  that that is now used if no policy given
+        book.setMissingCellPolicy(HSSFRow.RETURN_BLANK_AS_NULL);
+        
+        assertEquals(HSSFCell.CELL_TYPE_STRING,  row.getCell(0).getCellType());
+        assertEquals(HSSFCell.CELL_TYPE_NUMERIC, row.getCell(1).getCellType());
+        assertEquals(null, row.getCell(2));
+        assertEquals(null, row.getCell(3));
+        assertEquals(null, row.getCell(4));
+        assertEquals(HSSFCell.CELL_TYPE_NUMERIC, row.getCell(5).getCellType());
     }
 }