Tweak DateUtil, an add cell content fetching to the quick guide documentation

git-svn-id: https://svn.apache.org/repos/asf/poi/branches/ooxml@645150 13f79535-47bb-0310-9956-ffa450edef68

src/documentation/content/xdocs/spreadsheet/quick-guide.xml

@@ -43,6 +43,7 @@
                     <li><link href="#CreateDateCells">How to create date cells</link></li>
                     <li><link href="#CellTypes">Working with different types of cells</link></li>
                     <li><link href="#Iterator">Iterate over rows and cells</link></li>
+                    <li><link href="#CellContents">Getting the cell contents</link></li>
                     <li><link href="#TextExtraction">Text Extraction</link></li>
                     <li><link href="#Alignment">Aligning cells</link></li>
                     <li><link href="#Borders">Working with borders</link></li>
@@ -303,6 +304,53 @@
 	}
 				</source>
                 </section>
+
+                <anchor id="CellContents"/>
+                <section><title>Getting the cell contents</title>
+					<p>To get the contents of a cell, you first need to
+                    know what kind of cell it is (asking a string cell
+                    for its numeric contents will get you a 
+                    NumberFormatException for example). So, you will
+                    want to switch on the cell's type, and then call
+                    the appropriate getter for that cell.</p>
+                    <p>In the code below, we loop over every cell
+                    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());
+			}
+			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>
+
                 <anchor id="TextExtraction"/>
                 <section><title>Text Extraction</title>
 					<p>For most text extraction requirements, the standard

src/examples/src/org/apache/poi/ss/usermodel/examples/FromQuickGuide.java

@@ -16,18 +16,20 @@
 ==================================================================== */
 package org.apache.poi.ss.usermodel.examples;
 
+import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.util.Date;
 
-import org.apache.poi.hssf.usermodel.HSSFDateUtil;
 import org.apache.poi.hssf.usermodel.HSSFWorkbook;
 import org.apache.poi.ss.usermodel.Cell;
 import org.apache.poi.ss.usermodel.CellStyle;
 import org.apache.poi.ss.usermodel.CreationHelper;
+import org.apache.poi.ss.usermodel.DateUtil;
 import org.apache.poi.ss.usermodel.Row;
 import org.apache.poi.ss.usermodel.Sheet;
 import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.ss.usermodel.WorkbookFactory;
 import org.apache.poi.ss.util.CellReference;
 import org.apache.poi.xssf.usermodel.XSSFWorkbook;
 
@@ -35,7 +37,7 @@ import org.apache.poi.xssf.usermodel.XSSFWorkbook;
  * Various things from the quick guide documentation
  */
 public class FromQuickGuide {
-	public void newWorkbook() throws IOException {
+	public static void newWorkbook() throws IOException {
 		boolean doHSSF = true;
 		boolean doXSSF = true;
 		
@@ -53,7 +55,7 @@ public class FromQuickGuide {
 		}
 	}
 	
-	public void newSheet() throws IOException {
+	public static void newSheet() throws IOException {
 		Workbook[] wbs = new Workbook[] {
 				new HSSFWorkbook(), new XSSFWorkbook()
 		};
@@ -68,7 +70,7 @@ public class FromQuickGuide {
 		}
 	}
 	
-	public void newCells() throws IOException {
+	public static void newCells() throws IOException {
 		Workbook[] wbs = new Workbook[] {
 				new HSSFWorkbook(), new XSSFWorkbook()
 		};
@@ -97,7 +99,7 @@ public class FromQuickGuide {
 		}
 	}
 	
-	public void newDateCells() throws IOException {
+	public static void newDateCells() throws IOException {
 	    Workbook wb = new HSSFWorkbook();
 	    //Workbook wb = new XSSFWorkbook();
 	    CreationHelper createHelper = wb.getCreationHelper();
@@ -126,7 +128,7 @@ public class FromQuickGuide {
 	    fileOut.close();
 	}
 	
-	public void iterating() {
+	public static void iterating() {
 	    Workbook wb = new HSSFWorkbook();
 	    Sheet sheet = wb.createSheet("new sheet");
 	    
@@ -138,19 +140,39 @@ public class FromQuickGuide {
 	    }
 	}
 	
-	public void getCellContents(Sheet sheet) {
+	public static void getCellContents(Sheet sheet) {
 	    for (Row row : sheet) {
 	        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();
 	        	}
 	        }
 	    }
 	}
+	
+	public static void main(String[] args) throws Exception {
+		Workbook wb = WorkbookFactory.create(new FileInputStream("src/testcases/org/apache/poi/hssf/data/WithMoreVariousData.xlsx"));
+		getCellContents(wb.getSheetAt(0));
+	}
 }

src/java/org/apache/poi/ss/usermodel/DateUtil.java

@@ -280,6 +280,8 @@ public class DateUtil
         double d = cell.getNumericCellValue();
         if ( DateUtil.isValidExcelDate(d) ) {
             CellStyle style = cell.getCellStyle();
+            if(style == null) return false;
+            
             int i = style.getDataFormat();
             String f = style.getDataFormatString();
             bDate = isADateFormat(i, f);