Use append(char) instead of string where possible

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1894814 13f79535-47bb-0310-9956-ffa450edef68

poi-ooxml/src/main/java/org/apache/poi/xssf/binary/XSSFBHeaderFooter.java

         }
         if (center != null && center.length() > 0) {
             if (sb.length() > 0) {
-                sb.append(" ");
+                sb.append(' ');
             }
             sb.append(center);
         }
         if (right != null && right.length() > 0) {
             if (sb.length() > 0) {
-                sb.append(" ");
+                sb.append(' ');
             }
             sb.append(right);
         }

poi-ooxml/src/main/java/org/apache/poi/xssf/usermodel/XSSFConditionalFormatting.java

         boolean first = true;
         for (CellRangeAddress range : ranges) {
             if (!first) {
-                sb.append(" ");
+                sb.append(' ');
             } else {
                 first = false;
             }

poi-scratchpad/src/test/java/org/apache/poi/hemf/usermodel/TestHemfPicture.java

                         lastX = -1;
                     }
                     if (lastX > -1 && reference.getX() - lastX > fudgeFactorX) {
-                        sb.append(" ");
+                        sb.append(' ');
                     }
                     sb.append(extTextOutW.getText());
                     lastY = reference.getY();
                         lastX = -1;
                     }
                     if (lastX > -1 && reference.getX() - lastX > fudgeFactorX) {
-                        sb.append(" ");
+                        sb.append(' ');
                     }
                     String txt = extTextOutW.getText();
                     if (expectedParts.contains(txt)) {

poi/src/main/java/org/apache/poi/hssf/record/SupBookRecord.java

             case CH_ALT_STARTUP_DIR:
             case CH_LIB_DIR:
                 LOG.atWarn().log("EXCEL.EXE path unknown - using this directory instead: .");
-                sb.append(".").append(PATH_SEPERATOR);
+                sb.append('.').append(PATH_SEPERATOR);
                 break;
             default:
                 sb.append(c);

poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java

         StringBuilder sb = new StringBuilder(32);
         for (int i = 0; i < parts.length; i++) {
             if (i > 0) {
-                sb.append(",");
+                sb.append(',');
             }
             SheetNameFormatter.appendFormat(sb, getSheetName(sheetIndex));
-            sb.append("!");
+            sb.append('!');
             sb.append(parts[i]);
         }
         name.setNameDefinition(HSSFFormulaParser.parse(sb.toString(), this, FormulaType.NAMEDRANGE, sheetIndex));

poi/src/main/java/org/apache/poi/poifs/eventfilesystem/POIFSReader.java

             sb.setLength(0);
             int pathLength = path.length();
             for (int k = 0; k < pathLength; k++) {
-                sb.append("/").append(path.getComponent(k));
+                sb.append('/').append(path.getComponent(k));
             }
             byte[] data = IOUtils.toByteArray(istream);
-            sb.append("/").append(event.getName()).append(": ").append(data.length).append(" bytes read");
+            sb.append('/').append(event.getName()).append(": ").append(data.length).append(" bytes read");
             System.out.println(sb);
         } catch (IOException ignored) {
         }

poi/src/main/java/org/apache/poi/ss/format/CellFormatPart.java

 
 			boolean special = type.isSpecial(ch.charAt(0));
 			if (special)
-				sb.append("'");
+				sb.append('\'');
 			sb.append(ch);
 			if (special)
-				sb.append("'");
+				sb.append('\'');
 		}
         return sb.toString();
     }

poi/src/main/java/org/apache/poi/ss/formula/CellEvaluationFrame.java

     public String toString() {
         StringBuilder sb = new StringBuilder(64);
         sb.append(getClass().getName()).append(" [");
-        sb.append("]");
+        sb.append(']');
         return sb.toString();
     }
     /**

poi/src/main/java/org/apache/poi/ss/formula/CollaboratingWorkbooksEnvironment.java

                     if (count++>0) {
                         sb.append(", ");
                     }
-                    sb.append("'").append(i.next()).append("'");
+                    sb.append('\'').append(i.next()).append("'");
                 }
-                sb.append(")");
+                sb.append(')');
             }
             throw new WorkbookNotFoundException(sb.toString());
         }

poi/src/main/java/org/apache/poi/ss/formula/NameIdentifier.java

         sb.append(getClass().getName());
         sb.append(" [");
         if (_isQuoted) {
-            sb.append("'").append(_name).append("'");
+            sb.append('\'').append(_name).append("'");
         } else {
             sb.append(_name);
         }
-        sb.append("]");
+        sb.append(']');
         return sb.toString();
     }
 }

poi/src/main/java/org/apache/poi/ss/formula/SheetIdentifier.java

             sb.append(" [").append(_sheetIdentifier.getName()).append("]");
         }
         if (_sheetIdentifier.isQuoted()) {
-            sb.append("'").append(_sheetIdentifier.getName()).append("'");
+            sb.append('\'').append(_sheetIdentifier.getName()).append("'");
         } else {
             sb.append(_sheetIdentifier.getName());
         }

poi/src/main/java/org/apache/poi/ss/formula/SheetRangeIdentifier.java

         super.asFormulaString(sb);
         sb.append(':');
         if (_lastSheetIdentifier.isQuoted()) {
-            sb.append("'").append(_lastSheetIdentifier.getName()).append("'");
+            sb.append('\'').append(_lastSheetIdentifier.getName()).append("'");
         } else {
             sb.append(_lastSheetIdentifier.getName());
         }

poi/src/main/java/org/apache/poi/ss/formula/functions/Averageifs.java

             public void addValue(ValueEval value) {
                 if(!(value instanceof NumberEval)) return;
 
-                double d = ((NumberEval) value).getNumberValue();;
+                double d = ((NumberEval) value).getNumberValue();
                 sum += d;
                 count++;
 

poi/src/main/java/org/apache/poi/ss/usermodel/FractionFormat.java

 
             StringBuilder sb = new StringBuilder();
             if (isNeg){
-                sb.append("-");
+                sb.append('-');
             }
             sb.append(wholePart);
             return sb.toString();

poi/src/main/java/org/apache/poi/ss/util/CellRangeAddress.java

         StringBuilder sb = new StringBuilder();
         if (sheetName != null) {
             sb.append(SheetNameFormatter.format(sheetName));
-            sb.append("!");
+            sb.append('!');
         }
         CellReference cellRefFrom = new CellReference(getFirstRow(), getFirstColumn(),
                 useAbsoluteAddress, useAbsoluteAddress);

poi/src/main/java/org/apache/poi/ss/util/NormalisedDecimal.java

         sb.append(ws.substring(1));
         sb.append(' ');
         sb.append(getFractionalDigits());
-        sb.append("E");
+        sb.append('E');
         sb.append(getDecimalExponent());
-        sb.append("]");
+        sb.append(']');
         return sb.toString();
     }
 }

poi/src/test/java/org/apache/poi/hpsf/basic/TestMetaDataIPI.java

         StringBuilder sb = new StringBuilder();
         for (int i = 0; i < 10000; i++) {
             sb.append(s);
-            sb.append(" ");
+            sb.append(' ');
         }
         return sb.toString();
     }
         Random rand = new Random(0); // TODO - no Random - tests should be completely deterministic
         for (int i = 0; i < 5; i++) {
             sb.append(s);
-            sb.append(" ");
+            sb.append(' ');
             char j = (char) rand.nextInt(220);
             j += 33;
-            sb.append(">");
+            sb.append('>');
             sb.append(Character.valueOf(j));
-            sb.append("=");
+            sb.append('=');
             sb.append(umlaute[rand.nextInt(umlaute.length)]);
-            sb.append("<");
+            sb.append('<');
         }
         return sb;
     }