replace some uses of StringBuffer with StringBuilder

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1870046 13f79535-47bb-0310-9956-ffa450edef68

src/examples/src/org/apache/poi/hssf/usermodel/examples/InCellLists.java

@@ -220,7 +220,7 @@ public class InCellLists {
             buffer.append(listItem);
             buffer.append("\n");
         }
-        // The StringBuffer's contents are the source for the contents
+        // The StringBuilder's contents are the source for the contents
         // of the cell.
         cell.setCellValue(new HSSFRichTextString(buffer.toString().trim()));
         cell.setCellStyle(wrapStyle);
@@ -260,7 +260,7 @@ public class InCellLists {
             buffer.append("\n");
             itemNumber += increment;
         }
-        // The StringBuffer's contents are the source for the contents
+        // The StringBuilder's contents are the source for the contents
         // of the cell.
         cell.setCellValue(new HSSFRichTextString(buffer.toString().trim()));
         cell.setCellStyle(wrapStyle);
@@ -292,7 +292,7 @@ public class InCellLists {
             buffer.append(listItem);
             buffer.append("\n");
         }
-        // The StringBuffer's contents are the source for the contents
+        // The StringBuilder's contents are the source for the contents
         // of the cell.
         cell.setCellValue(new HSSFRichTextString(buffer.toString().trim()));
         cell.setCellStyle(wrapStyle);
@@ -338,7 +338,7 @@ public class InCellLists {
                 }
             }
         }
-        // The StringBuffer's contents are the source for the contents
+        // The StringBuilder's contents are the source for the contents
         // of the cell.
         cell.setCellValue(new HSSFRichTextString(buffer.toString().trim()));
         cell.setCellStyle(wrapStyle);
@@ -409,7 +409,7 @@ public class InCellLists {
             }
             highLevelItemNumber += highLevelIncrement;
         }
-        // The StringBuffer's contents are the source for the contents
+        // The StringBuilder's contents are the source for the contents
         // of the cell.
         cell.setCellValue(new HSSFRichTextString(buffer.toString().trim()));
         cell.setCellStyle(wrapStyle);
@@ -459,7 +459,7 @@ public class InCellLists {
                 }
             }
         }
-        // The StringBuffer's contents are the source for the contents
+        // The StringBuilder's contents are the source for the contents
         // of the cell.
         cell.setCellValue(new HSSFRichTextString(buffer.toString().trim()));
         cell.setCellStyle(wrapStyle);

src/examples/src/org/apache/poi/hssf/view/SVFractionalFormat.java

@@ -140,9 +140,9 @@ public class SVFractionalFormat extends Format {
           break;
         }
         Precision = AllowedError / Diff;
-        // This calcualtion of Precision does not always provide results within
+        // This calculation of Precision does not always provide results within
         // Allowed Error. It compensates for loss of significant digits that occurs.
-        // It helps to round the inprecise reciprocal values to i.
+        // It helps to round the imprecise reciprocal values to i.
         B = A;
         A = Num;
       }
@@ -161,7 +161,7 @@ public class SVFractionalFormat extends Format {
         Whole = -Whole;
       }
     }
-    return new StringBuffer().append(Whole).append(" ").append(Num).append("/").append(Den).toString();
+    return new StringBuilder().append(Whole).append(" ").append(Num).append("/").append(Den).toString();
   }
 
   /** This method formats the double in the units specified.
@@ -173,7 +173,7 @@ public class SVFractionalFormat extends Format {
     f -= Whole;
     long Num = Math.round(f * units);
 
-    return new StringBuffer().append(Whole).append(" ").append(Num).append("/").append(units).toString();
+    return new StringBuilder().append(Whole).append(" ").append(Num).append("/").append(units).toString();
   }
 
   public final String format(double val) {

src/examples/src/org/apache/poi/ss/examples/ToCSV.java

@@ -428,10 +428,9 @@ public class ToCSV {
      * @throws java.io.IOException Thrown to indicate and error occurred in the
      *                             underylying file system.
      */
-    private void saveCSVFile(File file)
+    private void saveCSVFile(File file) throws FileNotFoundException, IOException {
-                                     throws FileNotFoundException, IOException {
         ArrayList<String> line;
-        StringBuffer buffer;
+        StringBuilder buffer;
         String csvLineElement;
 
         // Open a writer onto the CSV file.
@@ -443,20 +442,20 @@ public class ToCSV {
             // all of the data recovered from the Excel workbooks' sheets, rows
             // and cells.
             for(int i = 0; i < this.csvData.size(); i++) {
-                buffer = new StringBuffer();
+                buffer = new StringBuilder();
 
                 // Get an element from the ArrayList that contains the data for
                 // the workbook. This element will itself be an ArrayList
                 // containing Strings and each String will hold the data recovered
                 // from a single cell. The for() loop is used to recover elements
                 // from this 'row' ArrayList one at a time and to write the Strings
-                // away to a StringBuffer thus assembling a single line for inclusion
+                // away to a StringBuilder thus assembling a single line for inclusion
                 // in the CSV file. If a row was empty or if it was short, then
                 // the ArrayList that contains it's data will also be shorter than
                 // some of the others. Therefore, it is necessary to check within
                 // the for loop to ensure that the ArrayList contains data to be
                 // processed. If it does, then an element will be recovered and
-                // appended to the StringBuffer.
+                // appended to the StringBuilder.
                 line = this.csvData.get(i);
                 for(int j = 0; j < this.maxRowWidth; j++) {
                     if(line.size() > j) {
@@ -572,7 +571,7 @@ public class ToCSV {
      *         speech mark characters correctly escaped.
      */
     private String escapeEmbeddedCharacters(String field) {
-        StringBuffer buffer;
+        StringBuilder buffer;
 
         // If the fields contents should be formatted to confrom with Excel's
         // convention....
@@ -584,7 +583,7 @@ public class ToCSV {
             // set of speech marks. Thus, "Yes" he said would become
             // """Yes"" he said"
             if(field.contains("\"")) {
-                buffer = new StringBuffer(field.replaceAll("\"", "\\\"\\\""));
+                buffer = new StringBuilder(field.replaceAll("\"", "\\\"\\\""));
                 buffer.insert(0, "\"");
                 buffer.append("\"");
             }
@@ -592,7 +591,7 @@ public class ToCSV {
                 // If the field contains either embedded separator or EOL
                 // characters, then escape the whole field by surrounding it
                 // with speech marks.
-                buffer = new StringBuffer(field);
+                buffer = new StringBuilder(field);
                 if((buffer.indexOf(this.separator)) > -1 ||
                          (buffer.indexOf("\n")) > -1) {
                     buffer.insert(0, "\"");

src/java/org/apache/poi/hssf/record/AbstractEscherHolderRecord.java

@@ -84,7 +84,7 @@ public abstract class AbstractEscherHolderRecord extends Record implements Clone
     @Override
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         final String nl = System.getProperty("line.separator");
         buffer.append('[' + getRecordName() + ']' + nl);

src/java/org/apache/poi/hssf/record/ArrayRecord.java

@@ -79,7 +79,7 @@ public final class ArrayRecord extends SharedValueRecordBase implements Cloneabl
 	}
 
 	public String toString() {
-		StringBuffer sb = new StringBuffer();
+		StringBuilder sb = new StringBuilder();
 		sb.append(getClass().getName()).append(" [ARRAY]\n");
 		sb.append(" range=").append(getRange()).append("\n");
 		sb.append(" options=").append(HexDump.shortToHex(_options)).append("\n");

src/java/org/apache/poi/hssf/record/AutoFilterInfoRecord.java

@@ -68,7 +68,7 @@ public final class AutoFilterInfoRecord extends StandardRecord implements Clonea
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[AUTOFILTERINFO]\n");
         buffer.append("    .numEntries          = ")

src/java/org/apache/poi/hssf/record/BOFRecord.java

@@ -225,7 +225,7 @@ public final class BOFRecord extends StandardRecord implements Cloneable {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[BOF RECORD]\n");
         buffer.append("    .version  = ").append(HexDump.shortToHex(getVersion())).append("\n");

src/java/org/apache/poi/hssf/record/BackupRecord.java

@@ -69,7 +69,7 @@ public final class BackupRecord
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[BACKUP]\n");
         buffer.append("    .backup          = ")

src/java/org/apache/poi/hssf/record/BlankRecord.java

@@ -117,7 +117,7 @@ public final class BlankRecord extends StandardRecord implements CellValueRecord
 
     public String toString()
     {
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
 
         sb.append("[BLANK]\n");
         sb.append("    row= ").append(HexDump.shortToHex(getRow())).append("\n");

src/java/org/apache/poi/hssf/record/BookBoolRecord.java

@@ -69,7 +69,7 @@ public final class BookBoolRecord
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[BOOKBOOL]\n");
         buffer.append("    .savelinkvalues  = ")

src/java/org/apache/poi/hssf/record/BottomMarginRecord.java

@@ -41,7 +41,7 @@ public final class BottomMarginRecord extends StandardRecord implements Margin,
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
         buffer.append( "[BottomMargin]\n" );
         buffer.append( "    .margin               = " )
                 .append( " (" ).append( getMargin() ).append( " )\n" );

src/java/org/apache/poi/hssf/record/BoundSheetRecord.java

@@ -122,7 +122,7 @@ public final class BoundSheetRecord extends StandardRecord {
 	}
 
 	public String toString() {
-		StringBuffer buffer = new StringBuffer();
+		StringBuilder buffer = new StringBuilder();
 
 		buffer.append("[BOUNDSHEET]\n");
 		buffer.append("    .bof        = ").append(HexDump.intToHex(getPositionOfBof())).append("\n");

src/java/org/apache/poi/hssf/record/CFRuleRecord.java

@@ -136,7 +136,7 @@ public final class CFRuleRecord extends CFRuleBase implements Cloneable {
 
     @Override
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
         buffer.append("[CFRULE]\n");
         buffer.append("    .condition_type   =").append(getConditionType()).append("\n");
         buffer.append("    OPTION FLAGS=0x").append(Integer.toHexString(getOptions())).append("\n");

src/java/org/apache/poi/hssf/record/CRNCountRecord.java

@@ -55,7 +55,7 @@ public final class CRNCountRecord extends StandardRecord {
 
 
 	public String toString() {
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         sb.append(getClass().getName()).append(" [XCT");
         sb.append(" nCRNs=").append(field_1_number_crn_records);
         sb.append(" sheetIx=").append(field_2_sheet_table_index);

src/java/org/apache/poi/hssf/record/CRNRecord.java

@@ -52,7 +52,7 @@ public final class CRNRecord extends StandardRecord {
 
 
 	public String toString() {
-		StringBuffer sb = new StringBuffer();
+		StringBuilder sb = new StringBuilder();
 		sb.append(getClass().getName()).append(" [CRN");
 		sb.append(" rowIx=").append(field_3_row_index);
 		sb.append(" firstColIx=").append(field_2_first_column_index);

src/java/org/apache/poi/hssf/record/CalcCountRecord.java

@@ -68,7 +68,7 @@ public final class CalcCountRecord extends StandardRecord implements Cloneable {
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[CALCCOUNT]\n");
         buffer.append("    .iterations     = ")

src/java/org/apache/poi/hssf/record/CalcModeRecord.java

@@ -96,7 +96,7 @@ public final class CalcModeRecord extends StandardRecord implements Cloneable {
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[CALCMODE]\n");
         buffer.append("    .calcmode       = ")

src/java/org/apache/poi/hssf/record/CodepageRecord.java

@@ -79,7 +79,7 @@ public final class CodepageRecord
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[CODEPAGE]\n");
         buffer.append("    .codepage        = ")

src/java/org/apache/poi/hssf/record/CommonObjectDataSubRecord.java

@@ -95,7 +95,7 @@ public final class CommonObjectDataSubRecord extends SubRecord implements Clonea
     @Override
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[ftCmo]\n");
         buffer.append("    .objectType           = ")

src/java/org/apache/poi/hssf/record/ContinueRecord.java

@@ -53,7 +53,7 @@ public final class ContinueRecord extends StandardRecord implements Cloneable {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[CONTINUE RECORD]\n");
         buffer.append("    .data = ").append(HexDump.toHex(_data)).append("\n");

src/java/org/apache/poi/hssf/record/CountryRecord.java

@@ -96,7 +96,7 @@ public final class CountryRecord
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[COUNTRY]\n");
         buffer.append("    .defaultcountry  = ")

src/java/org/apache/poi/hssf/record/DBCellRecord.java

@@ -77,7 +77,7 @@ public final class DBCellRecord extends StandardRecord implements Cloneable {
 
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[DBCELL]\n");
         buffer.append("    .rowoffset = ").append(HexDump.intToHex(field_1_row_offset)).append("\n");

src/java/org/apache/poi/hssf/record/DSFRecord.java

@@ -52,7 +52,7 @@ public final class DSFRecord extends StandardRecord {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[DSF]\n");
         buffer.append("    .options = ").append(HexDump.shortToHex(_options)).append("\n");

src/java/org/apache/poi/hssf/record/DVALRecord.java

@@ -129,7 +129,7 @@ public final class DVALRecord extends StandardRecord implements Cloneable {
 
 
 	public String toString() {
-		StringBuffer buffer = new StringBuffer();
+		StringBuilder buffer = new StringBuilder();
 
 		buffer.append("[DVAL]\n");
 		buffer.append("    .options      = ").append(getOptions()).append('\n');

src/java/org/apache/poi/hssf/record/DVRecord.java

@@ -240,7 +240,7 @@ public final class DVRecord extends StandardRecord implements Cloneable {
 
 
 	public String toString() {
-		StringBuffer sb = new StringBuffer();
+		StringBuilder sb = new StringBuilder();
 		sb.append("[DV]\n");
 		sb.append(" options=").append(Integer.toHexString(_option_flags));
 		sb.append(" title-prompt=").append(formatTextTitle(_promptTitle));
@@ -274,7 +274,7 @@ public final class DVRecord extends StandardRecord implements Cloneable {
 		return str;
 	}
 
-	private static void appendFormula(StringBuffer sb, String label, Formula f) {
+	private static void appendFormula(StringBuilder sb, String label, Formula f) {
 		sb.append(label);
 		
 		if (f == null) {

src/java/org/apache/poi/hssf/record/DateWindow1904Record.java

@@ -67,7 +67,7 @@ public final class DateWindow1904Record
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[1904]\n");
         buffer.append("    .is1904          = ")

src/java/org/apache/poi/hssf/record/DefaultColWidthRecord.java

@@ -69,7 +69,7 @@ public final class DefaultColWidthRecord extends StandardRecord implements Clone
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[DEFAULTCOLWIDTH]\n");
         buffer.append("    .colwidth      = ")

src/java/org/apache/poi/hssf/record/DefaultRowHeightRecord.java

@@ -95,7 +95,7 @@ public final class DefaultRowHeightRecord extends StandardRecord implements Clon
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[DEFAULTROWHEIGHT]\n");
         buffer.append("    .optionflags    = ")

src/java/org/apache/poi/hssf/record/DeltaRecord.java

@@ -49,7 +49,7 @@ public final class DeltaRecord extends StandardRecord implements Cloneable {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[DELTA]\n");
         buffer.append("    .maxchange = ").append(getMaxChange()).append("\n");

src/java/org/apache/poi/hssf/record/DimensionsRecord.java

@@ -144,7 +144,7 @@ public final class DimensionsRecord extends StandardRecord implements Cloneable
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[DIMENSIONS]\n");
         buffer.append("    .firstrow       = ")

src/java/org/apache/poi/hssf/record/DrawingSelectionRecord.java

@@ -57,7 +57,7 @@ public final class DrawingSelectionRecord extends StandardRecord implements Clon
 		}
 
 		public String debugFormatAsString() {
-			StringBuffer sb = new StringBuffer(32);
+			StringBuilder sb = new StringBuilder(32);
 			sb.append("ver+inst=").append(HexDump.shortToHex(_verAndInstance));
 			sb.append(" type=").append(HexDump.shortToHex(_type));
 			sb.append(" len=").append(HexDump.intToHex(_length));
@@ -115,7 +115,7 @@ public final class DrawingSelectionRecord extends StandardRecord implements Clon
 	}
 
 	public String toString() {
-		StringBuffer sb = new StringBuffer();
+		StringBuilder sb = new StringBuilder();
 
 		sb.append("[MSODRAWINGSELECTION]\n");
 		sb.append("    .rh       =(").append(_header.debugFormatAsString()).append(")\n");

src/java/org/apache/poi/hssf/record/EOFRecord.java

@@ -48,7 +48,7 @@ public final class EOFRecord extends StandardRecord implements Cloneable {
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[EOF]\n");
         buffer.append("[/EOF]\n");

src/java/org/apache/poi/hssf/record/EmbeddedObjectRefSubRecord.java

@@ -315,7 +315,7 @@ public final class EmbeddedObjectRefSubRecord extends SubRecord implements Clone
 	}
 
 	public String toString() {
-		StringBuffer sb = new StringBuffer();
+		StringBuilder sb = new StringBuilder();
 		sb.append("[ftPictFmla]\n");
 		sb.append("    .f2unknown     = ").append(HexDump.intToHex(field_1_unknown_int)).append("\n");
 		if (field_2_refPtg == null) {

src/java/org/apache/poi/hssf/record/EndSubRecord.java

@@ -53,7 +53,7 @@ public final class EndSubRecord extends SubRecord implements Cloneable {
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[ftEnd]\n");
 

src/java/org/apache/poi/hssf/record/ExtSSTRecord.java

@@ -111,7 +111,7 @@ public final class ExtSSTRecord extends ContinuableRecord {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[EXTSST]\n");
         buffer.append("    .dsst           = ")

src/java/org/apache/poi/hssf/record/ExternSheetRecord.java

@@ -70,7 +70,7 @@ public class ExternSheetRecord extends StandardRecord {
 		
 		@Override
 		public String toString() {
-			StringBuffer buffer = new StringBuffer();
+			StringBuilder buffer = new StringBuilder();
 			buffer.append("extBook=").append(_extBookIndex);
 			buffer.append(" firstSheet=").append(_firstSheetIndex);
 			buffer.append(" lastSheet=").append(_lastSheetIndex);
@@ -127,7 +127,7 @@ public class ExternSheetRecord extends StandardRecord {
 	
 	@Override
 	public String toString() {
-		StringBuffer sb = new StringBuffer();
+		StringBuilder sb = new StringBuilder();
 		int nItems = _list.size();
 		sb.append("[EXTERNSHEET]\n");
 		sb.append("   numOfRefs     = ").append(nItems).append("\n");

src/java/org/apache/poi/hssf/record/FeatHdrRecord.java

@@ -84,7 +84,7 @@ public final class FeatHdrRecord extends StandardRecord implements Cloneable  {
 	}
 
 	public String toString() {
-		StringBuffer buffer = new StringBuffer();
+		StringBuilder buffer = new StringBuilder();
 		buffer.append("[FEATURE HEADER]\n");
 		
 		// TODO ...

src/java/org/apache/poi/hssf/record/FeatRecord.java

@@ -101,7 +101,7 @@ public final class FeatRecord extends StandardRecord implements Cloneable  {
 	}
 
 	public String toString() {
-		StringBuffer buffer = new StringBuffer();
+		StringBuilder buffer = new StringBuilder();
 		buffer.append("[SHARED FEATURE]\n");
 		
 		// TODO ...

src/java/org/apache/poi/hssf/record/FileSharingRecord.java

@@ -100,7 +100,7 @@ public final class FileSharingRecord extends StandardRecord implements Cloneable
 
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[FILESHARING]\n");
         buffer.append("    .readonly       = ")

src/java/org/apache/poi/hssf/record/FnGroupCountRecord.java

@@ -75,7 +75,7 @@ public final class FnGroupCountRecord
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[FNGROUPCOUNT]\n");
         buffer.append("    .count            = ").append(getCount())

src/java/org/apache/poi/hssf/record/FontRecord.java

@@ -359,7 +359,7 @@ public final class FontRecord extends StandardRecord {
 	}
 
 	public String toString() {
-		StringBuffer sb = new StringBuffer();
+		StringBuilder sb = new StringBuilder();
 
 		sb.append("[FONT]\n");
 		sb.append("    .fontheight    = ").append(HexDump.shortToHex(getFontHeight())).append("\n");

src/java/org/apache/poi/hssf/record/FooterRecord.java

@@ -34,7 +34,7 @@ public final class FooterRecord extends HeaderFooterBase implements Cloneable {
 	}
 
 	public String toString() {
-		StringBuffer buffer = new StringBuffer();
+		StringBuilder buffer = new StringBuilder();
 
 		buffer.append("[FOOTER]\n");
 		buffer.append("    .footer = ").append(getText()).append("\n");

src/java/org/apache/poi/hssf/record/FormatRecord.java

@@ -84,7 +84,7 @@ public final class FormatRecord extends StandardRecord implements Cloneable {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[FORMAT]\n");
         buffer.append("    .indexcode       = ").append(HexDump.shortToHex(getIndexCode())).append("\n");

src/java/org/apache/poi/hssf/record/FtCblsSubRecord.java

@@ -60,7 +60,7 @@ public final class FtCblsSubRecord extends SubRecord implements Cloneable {
      */
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[FtCbls ]").append("\n");
         buffer.append("  size     = ").append(getDataSize()).append("\n");

src/java/org/apache/poi/hssf/record/FtCfSubRecord.java

@@ -67,7 +67,7 @@ public final class FtCfSubRecord extends SubRecord implements Cloneable {
      * Used by BiffViewer and other utilities.
      */
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
         buffer.append("[FtCf ]\n");
         buffer.append("  size     = ").append(length).append("\n");
         buffer.append("  flags    = ").append(HexDump.toHex(flags)).append("\n");

src/java/org/apache/poi/hssf/record/FtPioGrbitSubRecord.java

@@ -121,7 +121,7 @@ public final class FtPioGrbitSubRecord extends SubRecord implements Cloneable {
      * Used by BiffViewer and other utilities.
      */
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
         buffer.append("[FtPioGrbit ]\n");
         buffer.append("  size     = ").append(length).append("\n");
         buffer.append("  flags    = ").append(HexDump.toHex(flags)).append("\n");

src/java/org/apache/poi/hssf/record/GroupMarkerSubRecord.java

@@ -49,7 +49,7 @@ public final class GroupMarkerSubRecord extends SubRecord implements Cloneable {
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         String nl = System.getProperty("line.separator");
         buffer.append("[ftGmo]" + nl);

src/java/org/apache/poi/hssf/record/GutsRecord.java

@@ -139,7 +139,7 @@ public final class GutsRecord extends StandardRecord implements Cloneable {
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[GUTS]\n");
         buffer.append("    .leftgutter     = ")

src/java/org/apache/poi/hssf/record/HeaderRecord.java

@@ -37,7 +37,7 @@ public final class HeaderRecord extends HeaderFooterBase implements Cloneable {
 	}
 
 	public String toString() {
-		StringBuffer buffer = new StringBuffer();
+		StringBuilder buffer = new StringBuilder();
 
 		buffer.append("[HEADER]\n");
 		buffer.append("    .header = ").append(getText()).append("\n");

src/java/org/apache/poi/hssf/record/HideObjRecord.java

@@ -77,7 +77,7 @@ public final class HideObjRecord
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[HIDEOBJ]\n");
         buffer.append("    .hideobj         = ")

src/java/org/apache/poi/hssf/record/HyperlinkRecord.java

@@ -676,7 +676,7 @@ public final class HyperlinkRecord extends StandardRecord implements Cloneable {
 
     @Override
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[HYPERLINK RECORD]\n");
         buffer.append("    .range   = ").append(_range.formatAsString()).append("\n");

src/java/org/apache/poi/hssf/record/IndexRecord.java

@@ -107,7 +107,7 @@ public final class IndexRecord extends StandardRecord implements Cloneable {
     @Override
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[INDEX]\n");
         buffer.append("    .firstrow       = ")

src/java/org/apache/poi/hssf/record/InterfaceHdrRecord.java

@@ -44,7 +44,7 @@ public final class InterfaceHdrRecord extends StandardRecord {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[INTERFACEHDR]\n");
         buffer.append("    .codepage = ").append(HexDump.shortToHex(_codepage)).append("\n");

src/java/org/apache/poi/hssf/record/IterationRecord.java

@@ -64,7 +64,7 @@ public final class IterationRecord extends StandardRecord implements Cloneable {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[ITERATION]\n");
         buffer.append("    .flags      = ").append(HexDump.shortToHex(_flags)).append("\n");

src/java/org/apache/poi/hssf/record/LabelRecord.java

@@ -145,7 +145,7 @@ public final class LabelRecord extends Record implements CellValueRecordInterfac
     @Override
     public String toString()
     {
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
 		sb.append("[LABEL]\n");
 		sb.append("    .row       = ").append(HexDump.shortToHex(getRow())).append("\n");
 		sb.append("    .column    = ").append(HexDump.shortToHex(getColumn())).append("\n");

src/java/org/apache/poi/hssf/record/LbsDataSubRecord.java

@@ -266,7 +266,7 @@ public class LbsDataSubRecord extends SubRecord {
 
     @Override
     public String toString() {
-        StringBuffer sb = new StringBuffer(256);
+        StringBuilder sb = new StringBuilder(256);
 
         sb.append("[ftLbsData]\n");
         sb.append("    .unknownShort1 =").append(HexDump.shortToHex(_cbFContinued)).append("\n");
@@ -404,7 +404,7 @@ public class LbsDataSubRecord extends SubRecord {
 
         @Override
         public String toString(){
-            StringBuffer sb = new StringBuffer();
+            StringBuilder sb = new StringBuilder();
             sb.append("[LbsDropData]\n");
             sb.append("  ._wStyle:  ").append(_wStyle).append('\n');
             sb.append("  ._cLine:  ").append(_cLine).append('\n');

src/java/org/apache/poi/hssf/record/LeftMarginRecord.java

@@ -35,7 +35,7 @@ public final class LeftMarginRecord extends StandardRecord implements Margin, Cl
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
         buffer.append( "[LeftMargin]\n" );
         buffer.append( "    .margin               = " ).append( " (" ).append( getMargin() ).append( " )\n" );
         buffer.append( "[/LeftMargin]\n" );

src/java/org/apache/poi/hssf/record/MMSRecord.java

@@ -93,7 +93,7 @@ public final class MMSRecord
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[MMS]\n");
         buffer.append("    .addMenu        = ")

src/java/org/apache/poi/hssf/record/MulBlankRecord.java

@@ -100,7 +100,7 @@ public final class MulBlankRecord extends StandardRecord {
 	}
 
 	public String toString() {
-		StringBuffer buffer = new StringBuffer();
+		StringBuilder buffer = new StringBuilder();
 
 		buffer.append("[MULBLANK]\n");
 		buffer.append("row  = ").append(Integer.toHexString(getRow())).append("\n");

src/java/org/apache/poi/hssf/record/MulRKRecord.java

@@ -102,7 +102,7 @@ public final class MulRKRecord extends StandardRecord {
 
 	@Override
     public String toString() {
-		StringBuffer buffer = new StringBuffer();
+		StringBuilder buffer = new StringBuilder();
 
 		buffer.append("[MULRK]\n");
 		buffer.append("	.row	 = ").append(HexDump.shortToHex(getRow())).append("\n");

src/java/org/apache/poi/hssf/record/NameCommentRecord.java

@@ -112,7 +112,7 @@ public final class NameCommentRecord extends StandardRecord {
 
   @Override
   public String toString() {
-    final StringBuffer sb = new StringBuffer();
+    final StringBuilder sb = new StringBuilder();
 
     sb.append("[NAMECMT]\n");
     sb.append("    .record type            = ").append(HexDump.shortToHex(field_1_record_type)).append("\n");

src/java/org/apache/poi/hssf/record/NoteRecord.java

@@ -125,7 +125,7 @@ public final class NoteRecord extends StandardRecord implements Cloneable {
 	 * Used by BiffViewer and other utilities.
 	 */
 	public String toString() {
-		StringBuffer buffer = new StringBuffer();
+		StringBuilder buffer = new StringBuilder();
 
 		buffer.append("[NOTE]\n");
 		buffer.append("    .row    = ").append(field_1_row).append("\n");

src/java/org/apache/poi/hssf/record/NoteStructureSubRecord.java

@@ -68,7 +68,7 @@ public final class NoteStructureSubRecord extends SubRecord implements Cloneable
     @Override
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[ftNts ]").append("\n");
         buffer.append("  size     = ").append(getDataSize()).append("\n");

src/java/org/apache/poi/hssf/record/ObjRecord.java

@@ -135,7 +135,7 @@ public final class ObjRecord extends Record implements Cloneable {
 
 	@Override
 	public String toString() {
-		StringBuffer sb = new StringBuffer();
+		StringBuilder sb = new StringBuilder();
 
 		sb.append("[OBJ]\n");
 		if(subrecords != null) {	// there are special cases where this can be, see comments in constructor above

src/java/org/apache/poi/hssf/record/ObjectProtectRecord.java

@@ -73,7 +73,7 @@ public final class ObjectProtectRecord extends StandardRecord implements Cloneab
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[SCENARIOPROTECT]\n");
 	    buffer.append("    .protect         = ").append(getProtect())

src/java/org/apache/poi/hssf/record/OldSheetRecord.java

@@ -74,7 +74,7 @@ public final class OldSheetRecord {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[BOUNDSHEET]\n");
         buffer.append("    .bof        = ").append(HexDump.intToHex(getPositionOfBof())).append("\n");

src/java/org/apache/poi/hssf/record/OldStringRecord.java

@@ -92,7 +92,7 @@ public final class OldStringRecord {
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[OLD STRING]\n");
         buffer.append("    .string            = ")

src/java/org/apache/poi/hssf/record/PaletteRecord.java

@@ -54,7 +54,7 @@ public final class PaletteRecord extends StandardRecord {
 
     @Override
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[PALETTE]\n");
         buffer.append("  numcolors     = ").append(_colors.size()).append('\n');
@@ -233,7 +233,7 @@ public final class PaletteRecord extends StandardRecord {
 
         @Override
         public String toString() {
-            StringBuffer buffer = new StringBuffer();
+            StringBuilder buffer = new StringBuilder();
             buffer.append("  red   = ").append(_red & 0xff).append('\n');
             buffer.append("  green = ").append(_green & 0xff).append('\n');
             buffer.append("  blue  = ").append(_blue & 0xff).append('\n');

src/java/org/apache/poi/hssf/record/PaneRecord.java

@@ -54,7 +54,7 @@ public final class PaneRecord extends StandardRecord {
     @Override
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[PANE]\n");
         buffer.append("    .x                    = ")

src/java/org/apache/poi/hssf/record/PasswordRecord.java

@@ -57,7 +57,7 @@ public final class PasswordRecord extends StandardRecord {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[PASSWORD]\n");
         buffer.append("    .password = ").append(HexDump.shortToHex(field_1_password)).append("\n");

src/java/org/apache/poi/hssf/record/PasswordRev4Record.java

@@ -47,7 +47,7 @@ public final class PasswordRev4Record extends StandardRecord {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[PROT4REVPASSWORD]\n");
         buffer.append("    .password = ").append(HexDump.shortToHex(field_1_password)).append("\n");

src/java/org/apache/poi/hssf/record/PrintSetupRecord.java

@@ -279,7 +279,7 @@ public final class PrintSetupRecord extends StandardRecord {
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[PRINTSETUP]\n");
         buffer.append("    .papersize      = ").append(getPaperSize())

src/java/org/apache/poi/hssf/record/ProtectRecord.java

@@ -66,7 +66,7 @@ public final class ProtectRecord extends StandardRecord {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[PROTECT]\n");
         buffer.append("    .options = ").append(HexDump.shortToHex(_options)).append("\n");

src/java/org/apache/poi/hssf/record/ProtectionRev4Record.java

@@ -64,7 +64,7 @@ public final class ProtectionRev4Record extends StandardRecord {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[PROT4REV]\n");
         buffer.append("    .options = ").append(HexDump.shortToHex(_options)).append("\n");

src/java/org/apache/poi/hssf/record/RecalcIdRecord.java

@@ -68,7 +68,7 @@ public final class RecalcIdRecord extends StandardRecord {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[RECALCID]\n");
         buffer.append("    .reserved = ").append(HexDump.shortToHex(_reserved0)).append("\n");

src/java/org/apache/poi/hssf/record/RefModeRecord.java

@@ -74,7 +74,7 @@ public final class RefModeRecord
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[REFMODE]\n");
         buffer.append("    .mode           = ")

src/java/org/apache/poi/hssf/record/RefreshAllRecord.java

@@ -65,7 +65,7 @@ public final class RefreshAllRecord extends StandardRecord {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[REFRESHALL]\n");
         buffer.append("    .options      = ").append(HexDump.shortToHex(_options)).append("\n");

src/java/org/apache/poi/hssf/record/RightMarginRecord.java

@@ -35,7 +35,7 @@ public final class RightMarginRecord extends StandardRecord implements Margin {
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
         buffer.append( "[RightMargin]\n" );
         buffer.append( "    .margin               = " ).append( " (" ).append( getMargin() ).append( " )\n" );
         buffer.append( "[/RightMargin]\n" );

src/java/org/apache/poi/hssf/record/RowRecord.java

@@ -366,7 +366,7 @@ public final class RowRecord extends StandardRecord {
     }
     
     public String toString() {
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
 
         sb.append("[ROW]\n");
         sb.append("    .rownumber      = ").append(Integer.toHexString(getRowNumber()))

src/java/org/apache/poi/hssf/record/SCLRecord.java

@@ -44,7 +44,7 @@ public final class SCLRecord extends StandardRecord {
     @Override
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[SCL]\n");
         buffer.append("    .numerator            = ")

src/java/org/apache/poi/hssf/record/ScenarioProtectRecord.java

@@ -76,7 +76,7 @@ public final class ScenarioProtectRecord
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[SCENARIOPROTECT]\n");
 	    buffer.append("    .protect         = ").append(getProtect())

src/java/org/apache/poi/hssf/record/TabIdRecord.java

@@ -52,7 +52,7 @@ public final class TabIdRecord extends StandardRecord {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[TABID]\n");
         buffer.append("    .elements        = ").append(_tabids.length).append("\n");

src/java/org/apache/poi/hssf/record/TableStylesRecord.java

@@ -76,7 +76,7 @@ public final class TableStylesRecord extends StandardRecord {
 
 	@Override
 	public String toString() {
-		StringBuffer buffer = new StringBuffer();
+		StringBuilder buffer = new StringBuilder();
 
 		buffer.append("[TABLESTYLES]\n");
 		buffer.append("    .rt      =").append(HexDump.shortToHex(rt)).append('\n');

src/java/org/apache/poi/hssf/record/TopMarginRecord.java

@@ -38,7 +38,7 @@ public final class TopMarginRecord extends StandardRecord implements Margin {
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
         buffer.append( "[TopMargin]\n" );
         buffer.append( "    .margin               = " ).append( " (" ).append( getMargin() ).append( " )\n" );
         buffer.append( "[/TopMargin]\n" );

src/java/org/apache/poi/hssf/record/UncalcedRecord.java

@@ -45,7 +45,7 @@ public final class UncalcedRecord extends StandardRecord  {
 	}
 
 	public String toString() {
-		StringBuffer buffer = new StringBuffer();
+		StringBuilder buffer = new StringBuilder();
 		buffer.append("[UNCALCED]\n");
         buffer.append("    _reserved: ").append(_reserved).append('\n');
 		buffer.append("[/UNCALCED]\n");

src/java/org/apache/poi/hssf/record/UseSelFSRecord.java

@@ -49,7 +49,7 @@ public final class UseSelFSRecord extends StandardRecord {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[USESELFS]\n");
         buffer.append("    .options = ").append(HexDump.shortToHex(_options)).append("\n");

src/java/org/apache/poi/hssf/record/VCenterRecord.java

@@ -63,7 +63,7 @@ public final class VCenterRecord extends StandardRecord {
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[VCENTER]\n");
         buffer.append("    .vcenter        = ").append(getVCenter())

src/java/org/apache/poi/hssf/record/WindowProtectRecord.java

@@ -65,7 +65,7 @@ public final class WindowProtectRecord extends StandardRecord {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[WINDOWPROTECT]\n");
         buffer.append("    .options = ").append(HexDump.shortToHex(_options)).append("\n");

src/java/org/apache/poi/hssf/record/WriteAccessRecord.java

@@ -117,7 +117,7 @@ public final class WriteAccessRecord extends StandardRecord {
 	}
 
 	public String toString() {
-		StringBuffer buffer = new StringBuffer();
+		StringBuilder buffer = new StringBuilder();
 
 		buffer.append("[WRITEACCESS]\n");
 		buffer.append("    .name = ").append(field_1_username).append("\n");

src/java/org/apache/poi/hssf/record/WriteProtectRecord.java

@@ -44,7 +44,7 @@ public final class WriteProtectRecord extends StandardRecord {
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[WRITEPROTECT]\n");
         buffer.append("[/WRITEPROTECT]\n");

src/java/org/apache/poi/hssf/record/cf/BorderFormatting.java

@@ -430,7 +430,7 @@ public final class BorderFormatting implements Cloneable {
 
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
         buffer.append("    [Border Formatting]\n");
         buffer.append("          .lftln     = ").append(Integer.toHexString(getBorderLeft())).append("\n");
         buffer.append("          .rgtln     = ").append(Integer.toHexString(getBorderRight())).append("\n");

src/java/org/apache/poi/hssf/record/cf/ColorGradientFormatting.java

@@ -119,7 +119,7 @@ public final class ColorGradientFormatting implements Cloneable {
     }    
     
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
         buffer.append("    [Color Gradient Formatting]\n");
         buffer.append("          .clamp     = ").append(isClampToCurve()).append("\n");
         buffer.append("          .background= ").append(isAppliesToBackground()).append("\n");

src/java/org/apache/poi/hssf/record/cf/DataBarFormatting.java

@@ -119,7 +119,7 @@ public final class DataBarFormatting implements Cloneable {
     }
     
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
         buffer.append("    [Data Bar Formatting]\n");
         buffer.append("          .icon_only= ").append(isIconOnly()).append("\n");
         buffer.append("          .reversed = ").append(isReversed()).append("\n");

src/java/org/apache/poi/hssf/record/cf/IconMultiStateFormatting.java

@@ -97,7 +97,7 @@ public final class IconMultiStateFormatting implements Cloneable {
     }
     
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
         buffer.append("    [Icon Formatting]\n");
         buffer.append("          .icon_set = ").append(iconSet).append("\n");
         buffer.append("          .icon_only= ").append(isIconOnly()).append("\n");

src/java/org/apache/poi/hssf/record/cf/PatternFormatting.java

@@ -156,7 +156,7 @@ public final class PatternFormatting implements Cloneable {
     }
     
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
         buffer.append("    [Pattern Formatting]\n");
         buffer.append("          .fillpattern= ").append(Integer.toHexString(getFillPattern())).append("\n");
         buffer.append("          .fgcoloridx= ").append(Integer.toHexString(getFillForegroundColor())).append("\n");

src/java/org/apache/poi/hssf/record/cf/Threshold.java

@@ -102,7 +102,7 @@ public abstract class Threshold {
     }
 
     public String toString() {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
         buffer.append("    [CF Threshold]\n");
         buffer.append("          .type    = ").append(Integer.toHexString(type)).append("\n");
         buffer.append("          .formula = ").append(Arrays.toString(formula.getTokens())).append("\n");

src/java/org/apache/poi/hssf/record/chart/AreaFormatRecord.java

@@ -61,7 +61,7 @@ public final class AreaFormatRecord extends StandardRecord implements Cloneable
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[AREAFORMAT]\n");
         buffer.append("    .foregroundColor      = ")

src/java/org/apache/poi/hssf/record/chart/AreaRecord.java

@@ -50,7 +50,7 @@ public final class AreaRecord extends StandardRecord implements Cloneable {
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[AREA]\n");
         buffer.append("    .formatFlags          = ")

src/java/org/apache/poi/hssf/record/chart/AxisLineFormatRecord.java

@@ -48,7 +48,7 @@ public final class AxisLineFormatRecord extends StandardRecord implements Clonea
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[AXISLINEFORMAT]\n");
         buffer.append("    .axisType             = ")

src/java/org/apache/poi/hssf/record/chart/AxisOptionsRecord.java

@@ -72,7 +72,7 @@ public final class AxisOptionsRecord extends StandardRecord implements Cloneable
 
     public String toString()
     {
-        StringBuffer buffer = new StringBuffer();
+        StringBuilder buffer = new StringBuilder();
 
         buffer.append("[AXCEXT]\n");
         buffer.append("    .minimumCategory      = ")