Inspired by github pull-6, use a StringBuilder for quicker string appending

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1516969 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/src/java/org/apache/poi/ss/util/CellReference.java b/src/java/org/apache/poi/ss/util/CellReference.java
index 10b41055514f7f400981a8ff608f4b0ea5f0e8fe..c9bea9fd123f1afc0aa621fda4a71838f6005f87 100644 (file)
--- a/src/java/org/apache/poi/ss/util/CellReference.java
+++ b/src/java/org/apache/poi/ss/util/CellReference.java
@@ -420,7 +420,7 @@ public class CellReference {
                //  treat it as the 0th one
                int excelColNum = col + 1;
 
-               String colRef = "";
+               StringBuilder colRef = new StringBuilder(2);
                int colRemain = excelColNum;
 
                while(colRemain > 0) {
@@ -430,10 +430,10 @@ public class CellReference {
 
                        // The letter A is at 65
                        char colChar = (char)(thisPart+64);
-                       colRef = colChar + colRef;
+                       colRef.append(colChar);
                }
 
-               return colRef;
+               return colRef.toString();
        }
 
        /**