Fix bug #49377 - only call DecimalFormat.setRoundingMode on Java 1.6 - it's needed to match excel's rendering of numbers

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@951052 13f79535-47bb-0310-9956-ffa450edef68

src/documentation/content/xdocs/status.xml

@@ -34,6 +34,7 @@
 
     <changes>
         <release version="3.7-SNAPSHOT" date="2010-??-??">
+           <action dev="POI-DEVELOPERS" type="fix">49377 - only call DecimalFormat.setRoundingMode on Java 1.6 - it's needed to match excel's rendering of numbers</action>
            <action dev="POI-DEVELOPERS" type="fix">49378 - correct 1.6ism</action>
            <action dev="POI-DEVELOPERS" type="add">Parse the HSMF headers chunk if present, and use it to find Dates in text extraction if needed</action>
            <action dev="POI-DEVELOPERS" type="fix">48494 - detect and support time formats like HH:MM;HH:MM</action>

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

@@ -19,6 +19,8 @@ package org.apache.poi.ss.usermodel;
 import java.util.regex.Pattern;
 import java.util.regex.Matcher;
 import java.util.*;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import java.math.RoundingMode;
 import java.text.*;
 
@@ -415,7 +417,7 @@ public class DataFormatter {
 
         try {
             DecimalFormat df = new DecimalFormat(sb.toString(), decimalSymbols);
-            df.setRoundingMode(RoundingMode.HALF_UP);
+            setExcelStyleRoundingMode(df);
             return df;
         } catch(IllegalArgumentException iae) {
 
@@ -659,6 +661,30 @@ public class DataFormatter {
         result.setParseIntegerOnly(true);
         return result;
     }
+    
+    /**
+     * Enables excel style rounding mode (round half up)
+     *  on the Decimal Format if possible.
+     * This will work for Java 1.6, but isn't possible
+     *  on Java 1.5. 
+     */
+    public static void setExcelStyleRoundingMode(DecimalFormat format) {
+       try {
+          Method srm = format.getClass().getMethod("setRoundingMode", RoundingMode.class);
+          srm.invoke(format, RoundingMode.HALF_UP);
+       } catch(NoSuchMethodException e) {
+          // Java 1.5
+       } catch(IllegalAccessException iae) {
+          // Shouldn't happen
+          throw new RuntimeException("Unable to set rounding mode", iae);
+       } catch(InvocationTargetException ite) {
+          // Shouldn't happen
+          throw new RuntimeException("Unable to set rounding mode", ite);
+       } catch(SecurityException se) {
+          // Not much we can do here
+       }
+    }
+    
     /**
      * Format class for Excel's SSN format. This class mimics Excel's built-in
      * SSN formatting.

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

@@ -43,8 +43,8 @@ public class ExcelStyleDateFormatter extends SimpleDateFormat {
    private DecimalFormat format1digit = new DecimalFormat("0");
    private DecimalFormat format2digits = new DecimalFormat("00");
    {
-      format1digit.setRoundingMode(RoundingMode.HALF_UP);
-      format2digits.setRoundingMode(RoundingMode.HALF_UP);
+      DataFormatter.setExcelStyleRoundingMode(format1digit);
+      DataFormatter.setExcelStyleRoundingMode(format2digits);
    }
    
    private double dateToBeFormatted = 0.0;