Fix Javadocs

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1888939 13f79535-47bb-0310-9956-ffa450edef68

22 files changed, 183 insertions, 182 deletions

diff --git a/poi/src/main/java/org/apache/poi/extractor/ExtractorFactory.java b/poi/src/main/java/org/apache/poi/extractor/ExtractorFactory.java
index a8d2f2d492..d7363a5e8a 100644
--- a/poi/src/main/java/org/apache/poi/extractor/ExtractorFactory.java
+++ b/poi/src/main/java/org/apache/poi/extractor/ExtractorFactory.java
@@ -56,7 +56,7 @@ public final class ExtractorFactory {
     /**
      * Some OPCPackages are packed in side an OLE2 container.
      * If encrypted, the {@link DirectoryNode} is called {@link Decryptor#DEFAULT_POIFS_ENTRY "EncryptedPackage"},
-     * otherwise the node is called "Packge"
+     * otherwise the node is called "Package"
      */
     public static final String OOXML_PACKAGE = "Package";
 
diff --git a/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFDataFormatter.java b/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFDataFormatter.java
index ef3eb93154..9452f5c64b 100644
--- a/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFDataFormatter.java
+++ b/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFDataFormatter.java
@@ -40,26 +40,24 @@ import org.apache.poi.util.LocaleUtil;
  * prefix or suffix.
  * </p>
  * <p>
- * For example the Excel pattern <code>"$#,##0.00 "USD"_);($#,##0.00 "USD")"
- * </code> will be correctly formatted as "$1,000.00 USD" or "($1,000.00 USD)".
- * However the pattern <code>"00-00-00"</code> is incorrectly formatted by
+ * For example the Excel pattern {@code "$#,##0.00 "USD"_);($#,##0.00 "USD")"
+ * } will be correctly formatted as "$1,000.00 USD" or "($1,000.00 USD)".
+ * However the pattern {@code "00-00-00"} is incorrectly formatted by
  * DecimalFormat as "000000--". For Excel formats that are not compatible with
  * DecimalFormat, you can provide your own custom {@link Format} implementation
- * via <code>HSSFDataFormatter.addFormat(String,Format)</code>. The following
+ * via {@code HSSFDataFormatter.addFormat(String,Format)}. The following
  * custom formats are already provided by this class:
  * </p>
- * <pre>
  * <ul><li>SSN "000-00-0000"</li>
  *     <li>Phone Number "(###) ###-####"</li>
  *     <li>Zip plus 4 "00000-0000"</li>
  * </ul>
- * </pre>
  * <p>
  * If the Excel format pattern cannot be parsed successfully, then a default
  * format will be used. The default number format will mimic the Excel General
  * format: "#" for whole numbers and "#.##########" for decimal numbers. You
- * can override the default format pattern with <code>
- * HSSFDataFormatter.setDefaultNumberFormat(Format)</code>. <b>Note:</b> the
+ * can override the default format pattern with {@code
+ * HSSFDataFormatter.setDefaultNumberFormat(Format)}. <b>Note:</b> the
  * default format will only be used when a Format cannot be created from the
  * cell's data format string.
  */
diff --git a/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java b/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
index dac56c030b..dc938d2de7 100644
--- a/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
+++ b/poi/src/main/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
@@ -868,7 +868,6 @@ public final class HSSFWorkbook extends POIDocument implements Workbook {
      * Note that Excel allows sheet names up to 31 chars in length but other applications
      * (such as OpenOffice) allow more. Some versions of Excel crash with names longer than 31 chars,
      * others - truncate such names to 31 character.
-     * </p>
      * <p>
      * POI's SpreadsheetAPI silently truncates the input argument to 31 characters.
      * Example:
@@ -878,7 +877,6 @@ public final class HSSFWorkbook extends POIDocument implements Workbook {
      *     assert 31 == sheet.getSheetName().length();
      *     assert "My very long sheet name which i" == sheet.getSheetName();
      *     }</pre>
-     * </p>
      * <p>
      * Except the 31-character constraint, Excel applies some other rules:
      * <p>
@@ -895,7 +893,6 @@ public final class HSSFWorkbook extends POIDocument implements Workbook {
      * <li> closing square bracket (]) </li>
      * </ul>
      * The string MUST NOT begin or end with the single quote (') character.
-     * </p>
      *
      * @param sheetname sheetname to set for the sheet.
      * @return Sheet representing the new sheet.
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/FormulaParser.java b/poi/src/main/java/org/apache/poi/ss/formula/FormulaParser.java
index a05166e29e..b41e38baaa 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/FormulaParser.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/FormulaParser.java
@@ -83,16 +83,16 @@ import org.apache.poi.util.Internal;
 
 /**
  * This class parses a formula string into a List of tokens in RPN order.
- * Inspired by
- *           Lets Build a Compiler, by Jack Crenshaw
+ * Inspired by "Lets Build a Compiler" by Jack Crenshaw
  * BNF for the formula expression is :
+ * <pre>{@code
  * <expression> ::= <term> [<addop> <term>]*
  * <term> ::= <factor>  [ <mulop> <factor> ]*
  * <factor> ::= <number> | (<expression>) | <cellRef> | <function>
  * <function> ::= <functionName> ([expression [, expression]*])
+ * }</pre>
  * <p>
  * For POI internal use only
- * <p>
  */
 @Internal
 public final class FormulaParser {
@@ -158,7 +158,7 @@ public final class FormulaParser {
      * @param workbook    the parent workbook
      * @param formulaType the type of the formula
      * @param sheetIndex  the 0-based index of the sheet this formula belongs to.
-     *     The sheet index is required to resolve sheet-level names. <code>-1</code> means that
+     *     The sheet index is required to resolve sheet-level names. {@code -1} means that
      *     the scope of the name will be ignored and  the parser will match names only by name
      * @param rowIndex  - the related cell's row index in 0-based form (-1 if the formula is not cell related)
      *                     used to handle structured references that have the "#This Row" quantifier.
@@ -183,7 +183,7 @@ public final class FormulaParser {
      * @param workbook    the parent workbook
      * @param formulaType the type of the formula
      * @param sheetIndex  the 0-based index of the sheet this formula belongs to.
-     *     The sheet index is required to resolve sheet-level names. <code>-1</code> means that
+     *     The sheet index is required to resolve sheet-level names. {@code -1} means that
      *     the scope of the name will be ignored and  the parser will match names only by name
      *
      * @return array of parsed tokens
@@ -210,10 +210,10 @@ public final class FormulaParser {
         }
         return (Area3DPxg) arr[0];
     }
-    
+
     /** Read New Character From Input Stream */
     private void GetChar() {
-        // The intersection operator is a space.  We track whether the run of 
+        // The intersection operator is a space.  We track whether the run of
         // whitespace preceding "look" counts as an intersection operator.
         if (IsWhite(look)) {
             if (look == ' ') {
@@ -223,7 +223,7 @@ public final class FormulaParser {
         else {
             _inIntersection = false;
         }
-        
+
         // Check to see if we've walked off the end of the string.
         if (_pointer > _formulaLength) {
             throw new RuntimeException("Parsed past the end of the formula, pos: " + _pointer +
@@ -382,9 +382,6 @@ public final class FormulaParser {
             }
             return false;
         }
-        if (token instanceof OperandPtg) {
-            return false;
-        }
 
         return false;
     }
@@ -401,7 +398,7 @@ public final class FormulaParser {
     }
 
     /**
-     * @return <code>false</code> if sub-expression represented the specified ParseNode definitely
+     * @return {@code false} if sub-expression represented the specified ParseNode definitely
      * cannot appear on either side of the range (':') operator
      */
     private static boolean isValidRangeOperand(ParseNode a) {
@@ -432,12 +429,8 @@ public final class FormulaParser {
         }
 
         // one special case of ScalarConstantPtg
-        if (tkn == ErrPtg.REF_INVALID) {
-            return true;
-        }
-
         // All other ControlPtgs and ScalarConstantPtgs cannot be used with ':'
-        return false;
+        return tkn == ErrPtg.REF_INVALID;
     }
 
     /**
@@ -470,7 +463,7 @@ public final class FormulaParser {
         SkipWhite();
         int savePointer = _pointer;
         SheetIdentifier sheetIden = parseSheetName();
-        
+
         if (sheetIden == null) {
             resetPointer(savePointer);
         } else {
@@ -482,7 +475,7 @@ public final class FormulaParser {
         if (part1 == null) {
             if (sheetIden != null) {
                 if(look == '#'){  // error ref like MySheet!#REF!
-                    return new ParseNode(ErrPtg.valueOf(parseErrorLiteral()));  
+                    return new ParseNode(ErrPtg.valueOf(parseErrorLiteral()));
                 } else {
                     // Is it a named range?
                     String name = parseAsName();
@@ -587,13 +580,13 @@ public final class FormulaParser {
     }
 
 
-    
+
     private static final String specHeaders = "Headers";
     private static final String specAll = "All";
     private static final String specData = "Data";
     private static final String specTotals = "Totals";
     private static final String specThisRow = "This Row";
-    
+
     /**
      * Parses a structured reference, returns it as area reference.
      * Examples:
@@ -617,11 +610,10 @@ public final class FormulaParser {
      * Table1[[#This Row], [col1]]
      * Table1[ [col1]:[col2] ]
      * </pre>
-     * @param tableName
      * @return Area Reference for the given table
      */
     private ParseNode parseStructuredReference(String tableName) {
-        
+
         if ( ! (_ssVersion.equals(SpreadsheetVersion.EXCEL2007)) ) {
             throw new FormulaParseException("Structured references work only on XSSF (Excel 2007+)!");
         }
@@ -630,17 +622,17 @@ public final class FormulaParser {
            throw new FormulaParseException("Illegal table name: '" + tableName + "'");
         }
         String sheetName = tbl.getSheetName();
-        
+
         int startCol = tbl.getStartColIndex();
         int endCol = tbl.getEndColIndex();
         int startRow = tbl.getStartRowIndex();
         int endRow = tbl.getEndRowIndex();
-        
+
         // Do NOT return before done reading all the structured reference tokens from the input stream.
         // Throwing exceptions is okay.
         int savePtr0 = _pointer;
         GetChar();
-        
+
         boolean isTotalsSpec = false;
         boolean isThisRowSpec = false;
         boolean isDataSpec = false;
@@ -707,7 +699,7 @@ public final class FormulaParser {
                 }
             }
         }
-        
+
         if(nColQuantifiers == 0 && nSpecQuantifiers == 0){
             resetPointer(savePtr0);
             savePtr0 = _pointer;
@@ -757,15 +749,15 @@ public final class FormulaParser {
                 return new ParseNode(ErrPtg.VALUE_INVALID);
             } else {
                 throw new FormulaParseException(
-                        "Formula contained [#This Row] or [@] structured reference but this row < 0. " + 
+                        "Formula contained [#This Row] or [@] structured reference but this row < 0. " +
                         "Row index must be specified for row-referencing structured references.");
             }
         }
-        
+
         int actualStartRow = startRow;
         int actualEndRow = endRow;
         int actualStartCol = startCol;
-        int actualEndCol = endCol; 
+        int actualEndCol = endCol;
         if (nSpecQuantifiers > 0) {
         //Selecting rows
             if (nSpecQuantifiers == 1 && isAllSpec) {
@@ -787,14 +779,14 @@ public final class FormulaParser {
                 actualStartRow = actualEndRow;
             } else if ((nSpecQuantifiers == 1 && isThisRowSpec) || isThisRow) {
                 actualStartRow = _rowIndex; //The rowNum is 0 based
-                actualEndRow = _rowIndex; 
+                actualEndRow = _rowIndex;
             } else {
                 throw new FormulaParseException("The formula "+ _formulaString + " is illegal");
             }
         } else {
             if (isThisRow) { // there is a @
                 actualStartRow = _rowIndex; //The rowNum is 0 based
-                actualEndRow = _rowIndex; 
+                actualEndRow = _rowIndex;
             } else { // Really no special quantifiers
                 actualStartRow++;
                 if (tbl.getTotalsRowCount() > 0) actualEndRow--;
@@ -810,11 +802,11 @@ public final class FormulaParser {
             int startIdx = tbl.findColumnIndex(startColumnName);
             int endIdx = tbl.findColumnIndex(endColumnName);
             if (startIdx == -1 || endIdx == -1) {
-                throw new FormulaParseException("One of the columns "+ startColumnName +", "+ endColumnName +" doesn't exist in table "+ tbl.getName()); 
-            } 
+                throw new FormulaParseException("One of the columns "+ startColumnName +", "+ endColumnName +" doesn't exist in table "+ tbl.getName());
+            }
             actualStartCol = startCol+ startIdx;
             actualEndCol = startCol + endIdx;
-                
+
         } else if (nColQuantifiers == 1 && !isThisRow) {
             if (startColumnName == null) {
                 throw new IllegalStateException("Fatal error");
@@ -832,7 +824,7 @@ public final class FormulaParser {
         Ptg ptg = _book.get3DReferencePtg(new AreaReference(topLeft, bottomRight, _ssVersion), sheetIden);
         return new ParseNode(ptg);
     }
-    
+
     /**
      * Tries to parse the next as column - can contain whitespace
      * Caller should save pointer.
@@ -855,7 +847,7 @@ public final class FormulaParser {
         }
         Match(']');
         return name.toString();
-    }    
+    }
     /**
      * Tries to parse the next as special quantifier
      * Caller should save pointer.
@@ -899,7 +891,7 @@ public final class FormulaParser {
         if (look == '"') {
             return new ParseNode(new StringPtg(parseStringLiteral()));
         }
-        
+
         // from now on we can only be dealing with non-quoted identifiers
         // which will either be named ranges or functions
         String name = parseAsName();
@@ -929,7 +921,7 @@ public final class FormulaParser {
         throw new FormulaParseException("Specified name '"
                 + name + "' is not a range as expected.");
     }
-    
+
     private String parseAsName() {
         StringBuilder sb = new StringBuilder();
 
@@ -948,7 +940,7 @@ public final class FormulaParser {
 
     /**
      * @param ch unicode codepoint
-     * @return <code>true</code> if the specified character may be used in a defined name
+     * @return {@code true} if the specified character may be used in a defined name
      */
     private static boolean isValidDefinedNameChar(int ch) {
         if (Character.isLetterOrDigit(ch)) {
@@ -969,12 +961,11 @@ public final class FormulaParser {
         // includes special non-name control characters like ! $ : , ( ) [ ] and space
         return false;
     }
-    
+
     /**
      *
-     * @param sheetIden may be <code>null</code>
-     * @param part1
-     * @param part2 may be <code>null</code>
+     * @param sheetIden may be {@code null}
+     * @param part2 may be {@code null}
      */
     private ParseNode createAreaRefParseNode(SheetIdentifier sheetIden, SimpleRangePart part1,
             SimpleRangePart part2) throws FormulaParseException {
@@ -1015,14 +1006,14 @@ public final class FormulaParser {
     /**
      * Matches a zero or one letter-runs followed by zero or one digit-runs.
      * Either or both runs man optionally be prefixed with a single '$'.
-     * (copied+modified from {@link CellReference#CELL_REF_PATTERN})
+     * (copied+modified from CellReference.CELL_REF_PATTERN)
      */
     private static final Pattern CELL_REF_PATTERN = Pattern.compile("(\\$?[A-Za-z]+)?(\\$?[0-9]+)?");
 
     /**
      * Parses out a potential LHS or RHS of a ':' intended to produce a plain AreaRef.  Normally these are
      * proper cell references but they could also be row or column refs like "$AC" or "10"
-     * @return <code>null</code> (and leaves {@link #_pointer} unchanged if a proper range part does not parse out
+     * @return {@code null} (and leaves {@link #_pointer} unchanged if a proper range part does not parse out
      */
     private SimpleRangePart parseSimpleRangePart() {
         int ptr = _pointer-1; // TODO avoid StringIndexOutOfBounds
@@ -1132,9 +1123,9 @@ public final class FormulaParser {
         }
 
         /**
-         * @return <code>true</code> if the two range parts can be combined in an
+         * @return {@code true} if the two range parts can be combined in an
          * {@link AreaPtg} ( Note - the explicit range operator (:) may still be valid
-         * when this method returns <code>false</code> )
+         * when this method returns {@code false} )
          */
         public boolean isCompatibleForArea(SimpleRangePart part2) {
             return _type == part2._type;
@@ -1145,7 +1136,7 @@ public final class FormulaParser {
             return getClass().getName() + " [" + _rep + "]";
         }
     }
-    
+
     private String getBookName() {
         StringBuilder sb = new StringBuilder();
         GetChar();
@@ -1158,8 +1149,8 @@ public final class FormulaParser {
     }
 
     /**
-     * Note - caller should reset {@link #_pointer} upon <code>null</code> result
-     * @return The sheet name as an identifier <code>null</code> if '!' is not found in the right place
+     * Note - caller should reset {@link #_pointer} upon {@code null} result
+     * @return The sheet name as an identifier {@code null} if '!' is not found in the right place
      */
     private SheetIdentifier parseSheetName() {
         String bookName;
@@ -1171,10 +1162,10 @@ public final class FormulaParser {
 
         if (look == '\'') {
             Match('\'');
-            
+
             if (look == '[')
             	bookName = getBookName();
-            
+
             StringBuilder sb = new StringBuilder();
             boolean done = look == '\'';
             while(!done) {
@@ -1228,9 +1219,9 @@ public final class FormulaParser {
         }
         return null;
     }
-    
+
     /**
-     * If we have something that looks like [book]Sheet1: or 
+     * If we have something that looks like [book]Sheet1: or
      *  Sheet1, see if it's actually a range eg Sheet1:Sheet2!
      */
     private SheetIdentifier parseSheetRange(String bookname, NameIdentifier sheet1Name) {
@@ -1264,7 +1255,7 @@ public final class FormulaParser {
     }
 
     /**
-     * @return <code>true</code> if the specified name is a valid cell reference
+     * @return {@code true} if the specified name is a valid cell reference
      */
     private boolean isValidCellReference(String str) {
         //check range bounds against grid max
@@ -1297,7 +1288,7 @@ public final class FormulaParser {
      * Note - Excel function names are 'case aware but not case sensitive'.  This method may end
      * up creating a defined name record in the workbook if the specified name is not an internal
      * Excel function, and has not been encountered before.
-     * 
+     *
      * Side effect: creates workbook name if name is not recognized (name is probably a UDF)
      *
      * @param name case preserved function name (as it was entered/appeared in the formula).
@@ -1319,7 +1310,7 @@ public final class FormulaParser {
                     throw new FormulaParseException("Attempt to use name '" + name
                             + "' as a function, but defined name in workbook does not refer to a function");
                 }
-    
+
                 // calls to user-defined functions within the workbook
                 // get a Name token which points to a defined name record
                 nameToken = hName.createPtg();
@@ -1354,7 +1345,7 @@ public final class FormulaParser {
 
         return getFunction(name, nameToken, args);
     }
-    
+
     /**
      * Adds a name (named range or user defined function) to underlying workbook's names table
      */
@@ -1369,7 +1360,7 @@ public final class FormulaParser {
      * Generates the variable function ptg for the formula.
      * <p>
      * For IF Formulas, additional PTGs are added to the tokens
-     * @param name a {@link NamePtg} or {@link NameXPtg} or <code>null</code>
+     * @param name a {@link NamePtg} or {@link NameXPtg} or {@code null}
      * @return Ptg a null is returned if we're in an IF formula, it needs extreme manipulation and is handled in this function
      */
     private ParseNode getFunction(String name, Ptg namePtg, ParseNode[] args) {
@@ -1678,7 +1669,7 @@ public final class FormulaParser {
         if (!isPositive) {
             value = -value;
         }
-        return Double.valueOf(value);
+        return value;
     }
 
     private Ptg parseNumber() {
@@ -1930,7 +1921,7 @@ public final class FormulaParser {
             return result;
         }
     }
-    
+
     private ParseNode comparisonExpression() {
         ParseNode result = concatExpression();
         while (true) {
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/atp/YearFrac.java b/poi/src/main/java/org/apache/poi/ss/formula/atp/YearFrac.java
index a4f14b5436..9922654659 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/atp/YearFrac.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/atp/YearFrac.java
@@ -40,7 +40,8 @@ import org.apache.poi.ss.util.DateParser;
  *
  * The <b>basis</b> optionally specifies the behaviour of YEARFRAC as follows:
  *
- * <table border="0" cellpadding="1" cellspacing="0" summary="basis parameter description">
+ * <table>
+ *   <caption>basis parameter description</caption>
  *   <tr><th>Value</th><th>Days per Month</th><th>Days per Year</th></tr>
  *   <tr align='center'><td>0 (default)</td><td>30</td><td>360</td></tr>
  *   <tr align='center'><td>1</td><td>actual</td><td>actual</td></tr>
@@ -58,6 +59,7 @@ final class YearFrac implements FreeRefFunction {
 		// enforce singleton
 	}
 
+	@Override
 	public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec) {
 		int srcCellRow = ec.getRowIndex();
 		int srcCellCol = ec.getColumnIndex();
@@ -90,7 +92,7 @@ final class YearFrac implements FreeRefFunction {
 			String strVal = ((StringEval) ve).getStringValue();
 			Double dVal = OperandResolver.parseDouble(strVal);
 			if (dVal != null) {
-				return dVal.doubleValue();
+				return dVal;
 			}
 			LocalDate date = DateParser.parseLocalDate(strVal);
 			return DateUtil.getExcelDate(date, false);
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/eval/OperandResolver.java b/poi/src/main/java/org/apache/poi/ss/formula/eval/OperandResolver.java
index 2177e9115b..38f43137cc 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/eval/OperandResolver.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/eval/OperandResolver.java
@@ -111,7 +111,8 @@ public final class OperandResolver {
      * area depending on the coordinates of the calling cell.  Here is an example demonstrating
      * both selection from a single row area and a single column area in the same formula.
      *
-     *    <table border="1" cellpadding="1" cellspacing="1" summary="sample spreadsheet">
+     *    <table>
+     *      <caption>sample spreadsheet</caption>
      *      <tr><th>&nbsp;</th><th>&nbsp;A&nbsp;</th><th>&nbsp;B&nbsp;</th><th>&nbsp;C&nbsp;</th><th>&nbsp;D&nbsp;</th></tr>
      *      <tr><th>1</th><td>15</td><td>20</td><td>25</td><td>&nbsp;</td></tr>
      *      <tr><th>2</th><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td><td>200</td></tr>
@@ -122,7 +123,8 @@ public final class OperandResolver {
      * If the formula "=1000+A1:B1+D2:D3" is put into the 9 cells from A2 to C4, the spreadsheet
      * will look like this:
      *
-     *    <table border="1" cellpadding="1" cellspacing="1" summary="sample spreadsheet">
+     *    <table>
+     *      <caption>sample spreadsheet</caption>
      *      <tr><th>&nbsp;</th><th>&nbsp;A&nbsp;</th><th>&nbsp;B&nbsp;</th><th>&nbsp;C&nbsp;</th><th>&nbsp;D&nbsp;</th></tr>
      *      <tr><th>1</th><td>15</td><td>20</td><td>25</td><td>&nbsp;</td></tr>
      *      <tr><th>2</th><td>1215</td><td>1220</td><td>#VALUE!</td><td>200</td></tr>
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/functions/Countblank.java b/poi/src/main/java/org/apache/poi/ss/formula/functions/Countblank.java
index 560a776b54..1963071686 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/functions/Countblank.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/functions/Countblank.java
@@ -25,13 +25,15 @@ import org.apache.poi.ss.formula.functions.CountUtils.I_MatchPredicate;
  * Implementation for the function COUNTBLANK
  * <p>
  *  Syntax: COUNTBLANK ( range )
- *    <table border="0" cellpadding="1" cellspacing="0" summary="Parameter descriptions">
+ *    <table>
+ *        <caption>Parameter descriptions</caption>
  *      <tr><th>range&nbsp;&nbsp;&nbsp;</th><td>is the range of cells to count blanks</td></tr>
  *    </table>
  * </p>
  */
 public final class Countblank extends Fixed1ArgFunction {
 
+	@Override
 	public ValueEval evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg0) {
 
 		double result;
@@ -45,14 +47,11 @@ public final class Countblank extends Fixed1ArgFunction {
 		return new NumberEval(result);
 	}
 
-	private static final I_MatchPredicate predicate = new I_MatchPredicate() {
-
-		public boolean matches(ValueEval valueEval) {
-			// Note - only BlankEval counts
-			return valueEval == BlankEval.instance ||
-					// see https://support.office.com/en-us/article/COUNTBLANK-function-6a92d772-675c-4bee-b346-24af6bd3ac22
-					// "Cells with formulas that return "" (empty text) are also counted."
-					(valueEval instanceof StringEval && ((StringEval)valueEval).getStringValue().isEmpty());
-		}
+	private static final I_MatchPredicate predicate = valueEval -> {
+		// Note - only BlankEval counts
+		return valueEval == BlankEval.instance ||
+				// see https://support.office.com/en-us/article/COUNTBLANK-function-6a92d772-675c-4bee-b346-24af6bd3ac22
+				// "Cells with formulas that return "" (empty text) are also counted."
+				(valueEval instanceof StringEval && ((StringEval)valueEval).getStringValue().isEmpty());
 	};
 }
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/functions/Countif.java b/poi/src/main/java/org/apache/poi/ss/formula/functions/Countif.java
index 1f37d2e433..85444596d5 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/functions/Countif.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/functions/Countif.java
@@ -36,11 +36,11 @@ import org.apache.poi.ss.usermodel.FormulaError;
  * Implementation for the function COUNTIF
  * <p>
  *  Syntax: COUNTIF ( range, criteria )
- *    <table border="0" cellpadding="1" cellspacing="0" summary="Parameter descriptions">
+ *    <table>
+ *      <caption>Parameter descriptions</caption>
  *      <tr><th>range&nbsp;&nbsp;&nbsp;</th><td>is the range of cells to be counted based on the criteria</td></tr>
  *      <tr><th>criteria</th><td>is used to determine which cells to count</td></tr>
  *    </table>
- * </p>
  */
 public final class Countif extends Fixed2ArgFunction {
 
@@ -138,10 +138,7 @@ public final class Countif extends Fixed2ArgFunction {
         }
         @Override
         public String toString() {
-            StringBuilder sb = new StringBuilder(64);
-            sb.append(getClass().getName());
-            sb.append(" [").append(_representation).append("]");
-            return sb.toString();
+            return getClass().getName() + " [" + _representation + "]";
         }
         public String getRepresentation() {
             return _representation;
@@ -208,7 +205,7 @@ public final class Countif extends Fixed2ArgFunction {
                     // x is text that is not a number
                     return false;
                 }
-                return _value == val.doubleValue();
+                return _value == val;
             } else if((x instanceof NumberEval)) {
                 NumberEval ne = (NumberEval) x;
                 testValue = ne.getNumberValue();
@@ -304,7 +301,7 @@ public final class Countif extends Fixed2ArgFunction {
             }
             return false;
         }
-        
+
         public int getValue() {
             return _value;
         }
@@ -377,7 +374,7 @@ public final class Countif extends Fixed2ArgFunction {
         }
         /**
          * Translates Excel countif wildcard strings into java regex strings
-         * @return <code>null</code> if the specified value contains no special wildcard characters.
+         * @return {@code null} if the specified value contains no special wildcard characters.
          */
         public static Pattern getWildCardPattern(String value) {
             int len = value.length();
@@ -458,7 +455,7 @@ public final class Countif extends Fixed2ArgFunction {
 
     /**
      * Creates a criteria predicate object for the supplied criteria arg
-     * @return <code>null</code> if the arg evaluates to blank.
+     * @return {@code null} if the arg evaluates to blank.
      */
     /* package */ static I_MatchPredicate createCriteriaPredicate(ValueEval arg, int srcRowIndex, int srcColumnIndex) {
 
@@ -505,12 +502,12 @@ public final class Countif extends Fixed2ArgFunction {
 
         Boolean booleanVal = parseBoolean(value);
         if(booleanVal != null) {
-            return new BooleanMatcher(booleanVal.booleanValue(), operator);
+            return new BooleanMatcher(booleanVal, operator);
         }
 
         Double doubleVal = OperandResolver.parseDouble(value);
         if(doubleVal != null) {
-            return new NumberMatcher(doubleVal.doubleValue(), operator);
+            return new NumberMatcher(doubleVal, operator);
         }
         ErrorEval ee = parseError(value);
         if (ee != null) {
@@ -550,7 +547,7 @@ public final class Countif extends Fixed2ArgFunction {
     }
     /**
      * Boolean literals ('TRUE', 'FALSE') treated similarly but NOT same as numbers.
-     * @return <code>null</code> to represent blank values
+     * @return {@code null} to represent blank values
      */
     /* package */ static Boolean parseBoolean(String strRep) {
         if (strRep.length() < 1) {
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/functions/Errortype.java b/poi/src/main/java/org/apache/poi/ss/formula/functions/Errortype.java
index 486465a7b1..43d6d8560e 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/functions/Errortype.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/functions/Errortype.java
@@ -31,7 +31,8 @@ import org.apache.poi.ss.usermodel.FormulaError;
  * <b>ERROR.TYPE</b>(<b>errorValue</b>)</p>
  * <p>
  * Returns a number corresponding to the error type of the supplied argument.
- *    <table border="1" cellpadding="1" cellspacing="1" summary="Return values for ERROR.TYPE()">
+ *    <table>
+ *      <caption>Return values for ERROR.TYPE()</caption>
  *      <tr><td>errorValue</td><td>Return Value</td></tr>
  *      <tr><td>#NULL!</td><td>1</td></tr>
  *      <tr><td>#DIV/0!</td><td>2</td></tr>
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/functions/Index.java b/poi/src/main/java/org/apache/poi/ss/formula/functions/Index.java
index 1238f03125..eeac5d7952 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/functions/Index.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/functions/Index.java
@@ -33,7 +33,8 @@ import org.apache.poi.ss.formula.TwoDEval;
  * Syntax : <p>
  *  INDEX ( reference, row_num[, column_num [, area_num]])<p>
  *  INDEX ( array, row_num[, column_num])
- *    <table border="0" cellpadding="1" cellspacing="0" summary="Parameter descriptions">
+ *    <table>
+ *      <caption>Parameter descriptions</caption>
  *      <tr><th>reference</th><td>typically an area reference, possibly a union of areas</td></tr>
  *      <tr><th>array</th><td>a literal array value (currently not supported)</td></tr>
  *      <tr><th>row_num</th><td>selects the row within the array or area reference</td></tr>
@@ -43,6 +44,7 @@ import org.apache.poi.ss.formula.TwoDEval;
  */
 public final class Index implements Function2Arg, Function3Arg, Function4Arg, ArrayMode {
 
+	@Override
 	public ValueEval evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg0, ValueEval arg1) {
 		TwoDEval reference = convertFirstArg(arg0);
 
@@ -67,6 +69,7 @@ public final class Index implements Function2Arg, Function3Arg, Function4Arg, Ar
 			return e.getErrorEval();
 		}
 	}
+	@Override
 	public ValueEval evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg0, ValueEval arg1,
 			ValueEval arg2) {
 		TwoDEval reference = convertFirstArg(arg0);
@@ -79,6 +82,7 @@ public final class Index implements Function2Arg, Function3Arg, Function4Arg, Ar
 			return e.getErrorEval();
 		}
 	}
+	@Override
 	public ValueEval evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg0, ValueEval arg1,
 			ValueEval arg2, ValueEval arg3) {
 		throw new RuntimeException("Incomplete code"
@@ -104,6 +108,7 @@ public final class Index implements Function2Arg, Function3Arg, Function4Arg, Ar
 
 	}
 
+	@Override
 	public ValueEval evaluate(ValueEval[] args, int srcRowIndex, int srcColumnIndex) {
 		switch (args.length) {
 			case 2:
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/functions/Indirect.java b/poi/src/main/java/org/apache/poi/ss/formula/functions/Indirect.java
index 0eb2c04afc..2728e0ea25 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/functions/Indirect.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/functions/Indirect.java
@@ -35,7 +35,7 @@ import org.apache.poi.ss.usermodel.Table;
  *
  * INDIRECT() returns the cell or area reference denoted by the text argument.<p>
  *
- * <b>Syntax</b>:</br>
+ * <b>Syntax</b>:<br>
  * <b>INDIRECT</b>(<b>ref_text</b>,isA1Style)<p>
  *
  * <b>ref_text</b> a string representation of the desired reference as it would
@@ -51,6 +51,7 @@ public final class Indirect implements FreeRefFunction {
         // enforce singleton
     }
 
+    @Override
     public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec) {
         if (args.length < 1) {
             return ErrorEval.VALUE_INVALID;
@@ -88,7 +89,7 @@ public final class Indirect implements FreeRefFunction {
         }
         // numeric quantities follow standard boolean conversion rules
         // for strings, only "TRUE" and "FALSE" (case insensitive) are valid
-        return OperandResolver.coerceValueToBoolean(ve, false).booleanValue();
+        return OperandResolver.coerceValueToBoolean(ve, false);
     }
 
     private static ValueEval evaluateIndirect(final OperationEvaluationContext ec, String text,
@@ -116,7 +117,7 @@ public final class Indirect implements FreeRefFunction {
 
         if (Table.isStructuredReference.matcher(refText).matches()) {
             // The argument is structured reference
-            Area3DPxg areaPtg = null;
+            Area3DPxg areaPtg;
             try {
                 areaPtg = FormulaParser.parseStructuredReference(refText, (FormulaParsingWorkbook) ec.getWorkbook(), ec.getRowIndex());
             } catch (FormulaParseException e) {
@@ -142,7 +143,7 @@ public final class Indirect implements FreeRefFunction {
     /**
      * @return array of length 2: {workbookName, sheetName,}.  Second element will always be
      * present.  First element may be null if sheetName is unqualified.
-     * Returns <code>null</code> if text cannot be parsed.
+     * Returns {@code null} if text cannot be parsed.
      */
     private static String[] parseWorkbookAndSheetName(CharSequence text) {
         int lastIx = text.length() - 1;
@@ -212,7 +213,7 @@ public final class Indirect implements FreeRefFunction {
     }
 
     /**
-     * @return <code>null</code> if there is a syntax error in any escape sequence
+     * @return {@code null} if there is a syntax error in any escape sequence
      * (the typical syntax error is a single quote character not followed by another).
      */
     private static String unescapeString(CharSequence text) {
@@ -246,9 +247,6 @@ public final class Indirect implements FreeRefFunction {
         if (Character.isWhitespace(text.charAt(0))) {
             return true;
         }
-        if (Character.isWhitespace(text.charAt(lastIx))) {
-            return true;
-        }
-        return false;
+        return Character.isWhitespace(text.charAt(lastIx));
     }
 }
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/functions/LookupUtils.java b/poi/src/main/java/org/apache/poi/ss/formula/functions/LookupUtils.java
index 135614d3c7..975781d584 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/functions/LookupUtils.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/functions/LookupUtils.java
@@ -367,7 +367,8 @@ final class LookupUtils {
 	 * Processes the third argument to VLOOKUP, or HLOOKUP (<b>col_index_num</b>
 	 * or <b>row_index_num</b> respectively).<br>
 	 * Sample behaviour:
-	 *    <table border="0" cellpadding="1" cellspacing="2" summary="Sample behaviour">
+	 *    <table>
+	 *      <caption>Sample behaviour</caption>
 	 *      <tr><th>Input&nbsp;&nbsp;&nbsp;Return</th><th>Value&nbsp;&nbsp;</th><th>Thrown Error</th></tr>
 	 *      <tr><td>5</td><td>4</td><td>&nbsp;</td></tr>
 	 *      <tr><td>2.9</td><td>2</td><td>&nbsp;</td></tr>
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/functions/Subtotal.java b/poi/src/main/java/org/apache/poi/ss/formula/functions/Subtotal.java
index bbdb6c96e3..cc18fa7668 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/functions/Subtotal.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/functions/Subtotal.java
@@ -19,58 +19,57 @@ package org.apache.poi.ss.formula.functions;
 
 import static org.apache.poi.ss.formula.functions.AggregateFunction.subtotalInstance;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+
 import org.apache.poi.ss.formula.LazyRefEval;
 import org.apache.poi.ss.formula.eval.ErrorEval;
 import org.apache.poi.ss.formula.eval.EvaluationException;
-import org.apache.poi.ss.formula.eval.NotImplementedException;
 import org.apache.poi.ss.formula.eval.NotImplementedFunctionException;
 import org.apache.poi.ss.formula.eval.OperandResolver;
 import org.apache.poi.ss.formula.eval.ValueEval;
 
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Iterator;
-import java.util.List;
-
 /**
  * Implementation for the Excel function SUBTOTAL<p>
  *
  * <b>Syntax :</b> <br>
  *  SUBTOTAL ( <b>functionCode</b>, <b>ref1</b>, ref2 ... ) <br>
- *    <table border="1" cellpadding="1" cellspacing="0" summary="Parameter descriptions">
+ *    <table>
+ *      <caption>Parameter descriptions</caption>
  *      <tr><td><b>functionCode</b></td><td>(1-11) Selects the underlying aggregate function to be used (see table below)</td></tr>
  *      <tr><td><b>ref1</b>, ref2 ...</td><td>Arguments to be passed to the underlying aggregate function</td></tr>
  *    </table><br>
- * </p>
  *
- *  <table border="1" cellpadding="1" cellspacing="0" summary="Parameter descriptions">
+ *  <table>
+ *      <caption>Parameter descriptions</caption>
  *      <tr><th>functionCode</th><th>Aggregate Function</th></tr>
- *      <tr align='center'><td>1</td><td>AVERAGE</td></tr>
- *      <tr align='center'><td>2</td><td>COUNT</td></tr>
- *      <tr align='center'><td>3</td><td>COUNTA</td></tr>
- *      <tr align='center'><td>4</td><td>MAX</td></tr>
- *      <tr align='center'><td>5</td><td>MIN</td></tr>
- *      <tr align='center'><td>6</td><td>PRODUCT</td></tr>
- *      <tr align='center'><td>7</td><td>STDEV</td></tr>
- *      <tr align='center'><td>8</td><td>STDEVP *</td></tr>
- *      <tr align='center'><td>9</td><td>SUM</td></tr>
- *      <tr align='center'><td>10</td><td>VAR *</td></tr>
- *      <tr align='center'><td>11</td><td>VARP *</td></tr>
- *      <tr align='center'><td>101</td><td>AVERAGE</td></tr>
- *      <tr align='center'><td>102</td><td>COUNT</td></tr>
- *      <tr align='center'><td>103</td><td>COUNTA</td></tr>
- *      <tr align='center'><td>104</td><td>MAX</td></tr>
- *      <tr align='center'><td>105</td><td>MIN</td></tr>
- *      <tr align='center'><td>106</td><td>PRODUCT</td></tr>
- *      <tr align='center'><td>107</td><td>STDEV</td></tr>
- *      <tr align='center'><td>108</td><td>STDEVP *</td></tr>
- *      <tr align='center'><td>109</td><td>SUM</td></tr>
- *      <tr align='center'><td>110</td><td>VAR *</td></tr>
- *      <tr align='center'><td>111</td><td>VARP *</td></tr>
+ *      <tr><td>1</td><td>AVERAGE</td></tr>
+ *      <tr><td>2</td><td>COUNT</td></tr>
+ *      <tr><td>3</td><td>COUNTA</td></tr>
+ *      <tr><td>4</td><td>MAX</td></tr>
+ *      <tr><td>5</td><td>MIN</td></tr>
+ *      <tr><td>6</td><td>PRODUCT</td></tr>
+ *      <tr><td>7</td><td>STDEV</td></tr>
+ *      <tr><td>8</td><td>STDEVP *</td></tr>
+ *      <tr><td>9</td><td>SUM</td></tr>
+ *      <tr><td>10</td><td>VAR *</td></tr>
+ *      <tr><td>11</td><td>VARP *</td></tr>
+ *      <tr><td>101</td><td>AVERAGE</td></tr>
+ *      <tr><td>102</td><td>COUNT</td></tr>
+ *      <tr><td>103</td><td>COUNTA</td></tr>
+ *      <tr><td>104</td><td>MAX</td></tr>
+ *      <tr><td>105</td><td>MIN</td></tr>
+ *      <tr><td>106</td><td>PRODUCT</td></tr>
+ *      <tr><td>107</td><td>STDEV</td></tr>
+ *      <tr><td>108</td><td>STDEVP *</td></tr>
+ *      <tr><td>109</td><td>SUM</td></tr>
+ *      <tr><td>110</td><td>VAR *</td></tr>
+ *      <tr><td>111</td><td>VARP *</td></tr>
  *  </table><br>
  * * Not implemented in POI yet. Functions 101-111 are the same as functions 1-11 but with
  * the option 'ignore hidden values'.
- * <p>
  */
 public class Subtotal implements Function {
 
@@ -102,6 +101,7 @@ public class Subtotal implements Function {
 		throw EvaluationException.invalidValue();
 	}
 
+	@Override
 	public ValueEval evaluate(ValueEval[] args, int srcRowIndex, int srcColumnIndex) {
 		int nInnerArgs = args.length-1; // -1: first arg is used to select from a basic aggregate function
 		if (nInnerArgs < 1) {
@@ -109,7 +109,7 @@ public class Subtotal implements Function {
 		}
 
 		final Function innerFunc;
-		int functionCode = 0;
+		int functionCode;
 		try {
 			ValueEval ve = OperandResolver.getSingleValue(args[0], srcRowIndex, srcColumnIndex);
             functionCode = OperandResolver.coerceValueToInt(ve);
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/functions/Sumif.java b/poi/src/main/java/org/apache/poi/ss/formula/functions/Sumif.java
index 5ae3f1cba1..22431a920a 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/functions/Sumif.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/functions/Sumif.java
@@ -30,7 +30,8 @@ import org.apache.poi.ss.formula.functions.CountUtils.I_MatchPredicate;
  *
  * Syntax : <br>
  *  SUMIF ( <b>range</b>, <b>criteria</b>, sum_range ) <br>
- *    <table border="0" cellpadding="1" cellspacing="0" summary="Parameter descriptions">
+ *    <table>
+ *      <caption>Parameter descriptions</caption>
  *      <tr><th>range</th><td>The range over which criteria is applied.  Also used for addend values when the third parameter is not present</td></tr>
  *      <tr><th>criteria</th><td>The value or expression used to filter rows from <b>range</b></td></tr>
  *      <tr><th>sum_range</th><td>Locates the top-left corner of the corresponding range of addends - values to be added (after being selected by the criteria)</td></tr>
@@ -38,6 +39,7 @@ import org.apache.poi.ss.formula.functions.CountUtils.I_MatchPredicate;
  */
 public final class Sumif extends Var2or3ArgFunction {
 
+	@Override
 	public ValueEval evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg0, ValueEval arg1) {
 
 		AreaEval aeRange;
@@ -49,6 +51,7 @@ public final class Sumif extends Var2or3ArgFunction {
 		return eval(srcRowIndex, srcColumnIndex, arg1, aeRange, aeRange);
 	}
 
+	@Override
 	public ValueEval evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg0, ValueEval arg1,
 			ValueEval arg2) {
 
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/functions/Sumproduct.java b/poi/src/main/java/org/apache/poi/ss/formula/functions/Sumproduct.java
index 481e7f492d..8aca2a6389 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/functions/Sumproduct.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/functions/Sumproduct.java
@@ -36,7 +36,8 @@ import org.apache.poi.ss.formula.eval.ValueEval;
  *
  * Syntax : <br>
  *  SUMPRODUCT ( array1[, array2[, array3[, ...]]])
- *    <table border="0" cellpadding="1" cellspacing="0" summary="Parameter descriptions">
+ *    <table>
+ *      <caption>Parameter descriptions</caption>
  *      <tr><th>array1, ... arrayN&nbsp;&nbsp;</th><td>typically area references,
  *      possibly cell references or scalar values</td></tr>
  *    </table><br>
@@ -54,6 +55,7 @@ import org.apache.poi.ss.formula.eval.ValueEval;
 public final class Sumproduct implements Function {
 
 
+	@Override
 	public ValueEval evaluate(ValueEval[] args, int srcCellRow, int srcCellCol) {
 
 		int maxN = args.length;
@@ -87,8 +89,8 @@ public final class Sumproduct implements Function {
 		int maxN = evalArgs.length;
 
 		double term = 1D;
-		for(int n=0; n<maxN; n++) {
-			double val = getScalarValue(evalArgs[n]);
+		for (ValueEval evalArg : evalArgs) {
+			double val = getScalarValue(evalArg);
 			term *= val;
 		}
 		return new NumberEval(term);
@@ -178,13 +180,12 @@ public final class Sumproduct implements Function {
 	}
 
 	private static boolean areasAllSameSize(TwoDEval[] args, int height, int width) {
-		for (int i = 0; i < args.length; i++) {
-			TwoDEval areaEval = args[i];
+		for (TwoDEval areaEval : args) {
 			// check that height and width match
-			if(areaEval.getHeight() != height) {
+			if (areaEval.getHeight() != height) {
 				return false;
 			}
-			if(areaEval.getWidth() != width) {
+			if (areaEval.getWidth() != width) {
 				return false;
 			}
 		}
@@ -193,12 +194,12 @@ public final class Sumproduct implements Function {
 
 
 	/**
-	 * Determines a <code>double</code> value for the specified <code>ValueEval</code>.
-	 * @param isScalarProduct <code>false</code> for SUMPRODUCTs over area refs.
-	 * @throws EvaluationException if <code>ve</code> represents an error value.
+	 * Determines a {@code double} value for the specified {@code ValueEval}.
+	 * @param isScalarProduct {@code false} for SUMPRODUCTs over area refs.
+	 * @throws EvaluationException if {@code ve} represents an error value.
 	 * <p>
 	 * Note - string values and empty cells are interpreted differently depending on
-	 * <code>isScalarProduct</code>.  For scalar products, if any term is blank or a string, the
+	 * {@code isScalarProduct}.  For scalar products, if any term is blank or a string, the
 	 * error (#VALUE!) is raised.  For area (sum)products, if any term is blank or a string, the
 	 * result is zero.
 	 */
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/functions/Trend.java b/poi/src/main/java/org/apache/poi/ss/formula/functions/Trend.java
index 62eb545670..157663d0a1 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/functions/Trend.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/functions/Trend.java
@@ -47,7 +47,8 @@ import org.apache.poi.ss.formula.eval.ValueEval;
  *
  * Syntax:<br>
  * TREND(known_y's, known_x's, new_x's, constant)
- *    <table border="0" cellpadding="1" cellspacing="0" summary="Parameter descriptions">
+ *    <table>
+ *      <caption>Parameter descriptions</caption>
  *      <tr><th>known_y's, known_x's, new_x's</th><td>typically area references, possibly cell references or scalar values</td></tr>
  *      <tr><th>constant</th><td><b>TRUE</b> or <b>FALSE</b>:
  *      determines whether the regression line should include an intercept term</td></tr>
@@ -56,7 +57,6 @@ import org.apache.poi.ss.formula.eval.ValueEval;
  * of the same size as <b>known_y's</b>.<br>
  * If <b>new_x's</b> is not given, it is assumed to be the same as <b>known_x's</b><br>
  * If <b>constant</b> is omitted, it is assumed to be <b>TRUE</b>
- * </p>
  */
 
 public final class Trend implements Function {
@@ -72,6 +72,7 @@ public final class Trend implements Function {
         }
     }
 
+    @Override
     public ValueEval evaluate(ValueEval[] args, int srcRowIndex, int srcColumnIndex) {
         if (args.length < 1 || args.length > 4) {
             return ErrorEval.VALUE_INVALID;
diff --git a/poi/src/main/java/org/apache/poi/ss/usermodel/Workbook.java b/poi/src/main/java/org/apache/poi/ss/usermodel/Workbook.java
index 156d1b0d7a..484625755d 100644
--- a/poi/src/main/java/org/apache/poi/ss/usermodel/Workbook.java
+++ b/poi/src/main/java/org/apache/poi/ss/usermodel/Workbook.java
@@ -164,12 +164,11 @@ public interface Workbook extends Closeable, Iterable<Sheet> {
      *     POI's SpreadsheetAPI silently truncates the input argument to 31 characters.
      *     Example:
      *
-     *     <pre><code>
+     *     <pre>{@code
      *     Sheet sheet = workbook.createSheet("My very long sheet name which is longer than 31 chars"); // will be truncated
      *     assert 31 == sheet.getSheetName().length();
      *     assert "My very long sheet name which i" == sheet.getSheetName();
-     *     </code></pre>
-     * </p>
+     *     }</pre>
      *
      * Except the 31-character constraint, Excel applies some other rules:
      * <p>
@@ -186,7 +185,6 @@ public interface Workbook extends Closeable, Iterable<Sheet> {
      * <li> closing square bracket (]) </li>
      * </ul>
      * The string MUST NOT begin or end with the single quote (') character.
-     * </p>
      *
      * <p>
      * See {@link org.apache.poi.ss.util.WorkbookUtil#createSafeSheetName(String nameProposal)}
@@ -237,7 +235,7 @@ public interface Workbook extends Closeable, Iterable<Sheet> {
      * Get sheet with the given name
      *
      * @param name of the sheet
-     * @return Sheet with the name provided or <code>null</code> if it does not exist
+     * @return Sheet with the name provided or {@code null} if it does not exist
      */
     Sheet getSheet(String name);
 
@@ -258,7 +256,7 @@ public interface Workbook extends Closeable, Iterable<Sheet> {
     /**
      * Finds a font that matches the one with the supplied attributes
      *
-     * @return the font with the matched attributes or <code>null</code>
+     * @return the font with the matched attributes or {@code null}
      */
     Font findFont(boolean bold, short color, short fontHeight, String name, boolean italic, boolean strikeout, short typeOffset, byte underline);
 
@@ -337,7 +335,7 @@ public interface Workbook extends Closeable, Iterable<Sheet> {
 
     /**
      * @param name the name of the defined name
-     * @return the defined name with the specified name. <code>null</code> if not found.
+     * @return the defined name with the specified name. {@code null} if not found.
      */
     Name getName(String name);
 
@@ -479,12 +477,12 @@ public interface Workbook extends Closeable, Iterable<Sheet> {
     CreationHelper getCreationHelper();
 
     /**
-     * @return <code>false</code> if this workbook is not visible in the GUI
+     * @return {@code false} if this workbook is not visible in the GUI
      */
     boolean isHidden();
 
     /**
-     * @param hiddenFlag pass <code>false</code> to make the workbook visible in the GUI
+     * @param hiddenFlag pass {@code false} to make the workbook visible in the GUI
      */
     void setHidden(boolean hiddenFlag);
 
@@ -495,7 +493,7 @@ public interface Workbook extends Closeable, Iterable<Sheet> {
      *  ({@link #isSheetVeryHidden(int)})
      * </p>
      * @param sheetIx Number
-     * @return <code>true</code> if sheet is hidden
+     * @return {@code true} if sheet is hidden
      * @see #getSheetVisibility(int)
      */
     boolean isSheetHidden(int sheetIx);
@@ -507,7 +505,7 @@ public interface Workbook extends Closeable, Iterable<Sheet> {
      *  ({@link #isSheetHidden(int)})
      * </p>
      * @param sheetIx sheet index to check
-     * @return <code>true</code> if sheet is very hidden
+     * @return {@code true} if sheet is very hidden
      * @see #getSheetVisibility(int)
      */
     boolean isSheetVeryHidden(int sheetIx);
diff --git a/poi/src/main/java/org/apache/poi/ss/util/AreaReference.java b/poi/src/main/java/org/apache/poi/ss/util/AreaReference.java
index 6312673b57..97c2016e7c 100644
--- a/poi/src/main/java/org/apache/poi/ss/util/AreaReference.java
+++ b/poi/src/main/java/org/apache/poi/ss/util/AreaReference.java
@@ -383,7 +383,8 @@ public class AreaReference {
      * Returns a text representation of this area reference.
      * <p>
      *  Example return values:
-     *    <table border="0" cellpadding="1" cellspacing="0" summary="Example return values">
+     *    <table>
+     *      <caption>Example return values</caption>
      *      <tr><th align='left'>Result</th><th align='left'>Comment</th></tr>
      *      <tr><td>A1:A1</td><td>Single cell area reference without sheet</td></tr>
      *      <tr><td>A1:$C$1</td><td>Multi-cell area reference without sheet</td></tr>
diff --git a/poi/src/main/java/org/apache/poi/ss/util/CellReference.java b/poi/src/main/java/org/apache/poi/ss/util/CellReference.java
index f1132285ac..75bc7ec7b0 100644
--- a/poi/src/main/java/org/apache/poi/ss/util/CellReference.java
+++ b/poi/src/main/java/org/apache/poi/ss/util/CellReference.java
@@ -290,13 +290,14 @@ public class CellReference implements GenericRecord {
      * reference is valid (in range) becomes important.
      * <p>
      * Note - that the maximum sheet size varies across Excel versions:
-     * <blockquote><table border="0" cellpadding="1" cellspacing="0"
-     *                 summary="Notable cases.">
+     * <table>
+     *   <caption>Notable cases.</caption>
      *   <tr><th>Version&nbsp;&nbsp;</th><th>File Format&nbsp;&nbsp;</th>
      *   	<th>Last Column&nbsp;&nbsp;</th><th>Last Row</th></tr>
      *   <tr><td>97-2003</td><td>BIFF8</td><td>"IV" (2^8)</td><td>65536 (2^14)</td></tr>
      *   <tr><td>2007</td><td>BIFF12</td><td>"XFD" (2^14)</td><td>1048576 (2^20)</td></tr>
-     * </table></blockquote>
+     * </table>
+     *
      * POI currently targets BIFF8 (Excel 97-2003), so the following behaviour can be observed for
      * this method:
      * <blockquote><table border="0" cellpadding="1" cellspacing="0"
@@ -482,7 +483,8 @@ public class CellReference implements GenericRecord {
      * Returns a text representation of this cell reference.
      * <p>
      *  Example return values:
-     *	<table border="0" cellpadding="1" cellspacing="0" summary="Example return values">
+     *	<table>
+     *	  <caption>Example return values</caption>
      *	  <tr><th align='left'>Result</th><th align='left'>Comment</th></tr>
      *	  <tr><td>A1</td><td>Cell reference without sheet</td></tr>
      *	  <tr><td>Sheet1!A1</td><td>Standard sheet name</td></tr>
diff --git a/poi/src/main/java/org/apache/poi/ss/util/NumberToTextConverter.java b/poi/src/main/java/org/apache/poi/ss/util/NumberToTextConverter.java
index c41cc96f67..50787ae832 100644
--- a/poi/src/main/java/org/apache/poi/ss/util/NumberToTextConverter.java
+++ b/poi/src/main/java/org/apache/poi/ss/util/NumberToTextConverter.java
@@ -31,7 +31,8 @@ package org.apache.poi.ss.util;
  * </ul>
  * IEEE 64-bit Double Rendering Comparison
  *
- * <table border="1" cellpadding="2" cellspacing="0" summary="IEEE 64-bit Double Rendering Comparison">
+ * <table>
+ * <caption>IEEE 64-bit Double Rendering Comparison</caption>
  * <tr><th>Raw bits</th><th>Java</th><th>Excel</th></tr>
  *
  * <tr><td>0x0000000000000000L</td><td>0.0</td><td>0</td></tr>
diff --git a/poi/src/main/java/org/apache/poi/ss/util/cellwalk/CellWalkContext.java b/poi/src/main/java/org/apache/poi/ss/util/cellwalk/CellWalkContext.java
index ecf80895f2..09dfbd176c 100644
--- a/poi/src/main/java/org/apache/poi/ss/util/cellwalk/CellWalkContext.java
+++ b/poi/src/main/java/org/apache/poi/ss/util/cellwalk/CellWalkContext.java
@@ -24,7 +24,8 @@ public interface CellWalkContext {
      * from top left cell and ends at bottom right cell. Here is a
      * brief example (number in cell is it's ordinal number):
      *
-     * <table border="1">
+     * <table>
+     *   <caption>ordinal number example</caption>
      *   <tbody>
      *     <tr><td>1</td><td>2</td></tr>
      *     <tr><td>3</td><td>4</td></tr>
diff --git a/poi/src/main/java/org/apache/poi/util/Removal.java b/poi/src/main/java/org/apache/poi/util/Removal.java
index 0b618998ef..f4c19441d6 100644
--- a/poi/src/main/java/org/apache/poi/util/Removal.java
+++ b/poi/src/main/java/org/apache/poi/util/Removal.java
@@ -38,11 +38,11 @@ import java.lang.annotation.Documented;
  * removed in the n+2 release, a later version should be specified by this
  * annotation. The annotation version number should not include beta</p>
  *
- * <p>For example, a feature with a <code>&#64;deprecated POI 3.15 beta 3</code>
+ * <p>For example, a feature with a {@code @deprecated POI 3.15 beta 3}
  * is deprecated in POI 3.15 and 3.16 and becomes eligible for deletion during
  * the POI 3.17 release series, and may be deleted immediately after POI 3.16 is
- * released. This would be annotated <code>&#64;Removal(version="3.17")</p>.
- * 
+ * released. This would be annotated {@code @Removal(version="3.17")}</p>.
+ *
  * @since POI-3.15 beta 3
  */
 @Documented
@@ -50,12 +50,14 @@ import java.lang.annotation.Documented;
 public @interface Removal {
     /**
      * The POI version when this feature may be removed.
-     * 
+     *
      * To ensure that the version number can be compared to the current version
      * and a unit test can generate a warning if a removal-eligible feature has
      * not been removed yet, the version number should adhere to the following format:
+     * <pre>{@code
      * Format: "(?<major>\d+)\.(?<minor>\d+)"
      * Example: "3.15"
+     * }</pre>
      */
     String version() default "";
     // TODO: Verify that the version syntax is valid by parsing with a version-aware parser like