From d2cde65c30d7f197231367ee514cf47cd0dd422b Mon Sep 17 00:00:00 2001
From: Nick Burch <nick@apache.org>
Date: Wed, 27 May 2015 17:15:17 +0000
Subject: [PATCH] #57951 Use BigDecimal in some cases in
 DataFormatter.formatRawCellContents, to avoid rounding problems on JDK8.
 Patch from Robert Kish

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1682083 13f79535-47bb-0310-9956-ffa450edef68
---
 .../poi/ss/usermodel/DataFormatter.java       | 23 ++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/src/java/org/apache/poi/ss/usermodel/DataFormatter.java b/src/java/org/apache/poi/ss/usermodel/DataFormatter.java
index 1d7c598828..766ded18fe 100644
--- a/src/java/org/apache/poi/ss/usermodel/DataFormatter.java
+++ b/src/java/org/apache/poi/ss/usermodel/DataFormatter.java
@@ -20,6 +20,7 @@
 ==================================================================== */
 package org.apache.poi.ss.usermodel;
 
+import java.math.BigDecimal;
 import java.math.RoundingMode;
 import java.text.DateFormatSymbols;
 import java.text.DecimalFormat;
@@ -38,6 +39,8 @@ import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import org.apache.poi.ss.util.NumberToTextConverter;
+
 
 /**
  * DataFormatter contains methods for formatting the value stored in an
@@ -755,14 +758,28 @@ public class DataFormatter {
                 return invalidDateTimeString;
             }
         }
+        
         // else Number
         Format numberFormat = getFormat(value, formatIndex, formatString);
         if (numberFormat == null) {
             return String.valueOf(value);
         }
-        // RK: This hack handles scientific notation by adding the missing + back.
-        String result = numberFormat.format(new Double(value));
-        if (result.contains("E") && !result.contains("E-")) {
+        
+        // When formatting 'value', double to text to BigDecimal produces more
+        // accurate results than double to Double in JDK8 (as compared to
+        // previous versions). However, if the value contains E notation, this
+        // would expand the values, which we do not want, so revert to
+        // original method.
+        String result;
+        final String textValue = NumberToTextConverter.toText(value);
+        if (textValue.indexOf('E') > -1) {
+            result = numberFormat.format(new Double(value));
+        }
+        else {
+            result = numberFormat.format(new BigDecimal(textValue));
+        }
+        // Complete scientific notation by adding the missing +.
+        if (result.indexOf('E') > -1 && !result.contains("E-")) {
             result = result.replaceFirst("E", "E+");
         }
         return result;