diff --git a/.gitignore b/.gitignore
index 6c5d53050..fafd4b6ff 100644
--- a/.gitignore
+++ b/.gitignore
@@ -27,9 +27,9 @@ lib/
 
 # XPath parser generated during compilation
 /src/org/apache/xalan/processor/XSLProcessorVersion.java
-/src/org/apache/xalan/xsltc/compiler/XPathLexer.java
-/src/org/apache/xalan/xsltc/compiler/XPathParser.java
-/src/org/apache/xalan/xsltc/compiler/sym.java
+xalan/src/main/java/org/apache/xalan/xsltc/compiler/XPathLexer.java
+xalan/src/main/java/org/apache/xalan/xsltc/compiler/XPathParser.java
+xalan/src/main/java/org/apache/xalan/xsltc/compiler/sym.java
 
 # Stylebook processing progress flags.
 /stylebook/sources/xalan/DONE
diff --git a/pom.xml b/pom.xml
index c5d459543..6f0e0cd71 100644
--- a/pom.xml
+++ b/pom.xml
@@ -21,13 +21,13 @@
     <stylebook.classpath>
       "stylebook/stylebook-1.0-b3_xalan-2.jar${path.separator}serializer/target/classes${path.separator}xalan/target/classes${path.separator}"
     </stylebook.classpath>
-    <maven-compiler-plugin.version>3.11.0</maven-compiler-plugin.version>
-    <exec-maven-plugin.version>3.1.0</exec-maven-plugin.version>
+    <maven-compiler-plugin.version>3.12.1</maven-compiler-plugin.version>
+    <exec-maven-plugin.version>3.1.1</exec-maven-plugin.version>
     <maven-shade-plugin.version>3.5.1</maven-shade-plugin.version>
-    <junit-jupiter.version>5.10.1</junit-jupiter.version>
+    <junit-jupiter.version>5.10.2</junit-jupiter.version>
     <!-- TODO: Upgrade to 5.x after dropping requirement to build on JDK 8 -->
     <mockito.version>4.11.0</mockito.version>
-    <maven-javadoc-plugin.version>3.6.0</maven-javadoc-plugin.version>
+    <maven-javadoc-plugin.version>3.6.3</maven-javadoc-plugin.version>
     <maven-source-plugin.version>3.3.0</maven-source-plugin.version>
   </properties>
 
@@ -264,7 +264,7 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-surefire-plugin</artifactId>
-          <version>3.2.2</version>
+          <version>3.2.5</version>
           <configuration>
             <argLine>${maven-surefire-plugin.argLine}</argLine>
           </configuration>
@@ -423,7 +423,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-site-plugin</artifactId>
-        <version>3.7.1</version>
+        <version>3.12.1</version>
       </plugin>
 
       <!-- Maven finds this without assistance, but grumbles about
@@ -431,7 +431,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-project-info-reports-plugin</artifactId>
-        <version>3.4.5</version>
+        <version>3.5.0</version>
       </plugin>
 
       <!-- During cleaning phase, empty directories ./build and ./lib, which
@@ -459,7 +459,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-resources-plugin</artifactId>
-        <version>3.0.2</version>
+        <version>3.3.1</version>
         <executions>
           <execution>
             <id>copy-resources</id>
diff --git a/xalan/src/main/java/org/apache/xalan/extensions/ExtensionHandlerJava.java b/xalan/src/main/java/org/apache/xalan/extensions/ExtensionHandlerJava.java
index 5c16b0376..269e90528 100644
--- a/xalan/src/main/java/org/apache/xalan/extensions/ExtensionHandlerJava.java
+++ b/xalan/src/main/java/org/apache/xalan/extensions/ExtensionHandlerJava.java
@@ -43,12 +43,6 @@ public abstract class ExtensionHandlerJava extends ExtensionHandler
    * needed.
    *
    * @param namespaceUri the extension namespace URI that I'm implementing
-   * @param funcNames    string containing list of functions of extension NS
-   * @param lang         language of code implementing the extension
-   * @param srcURL       value of src attribute (if any) - treated as a URL
-   *                     or a classname depending on the value of lang. If
-   *                     srcURL is not null, then scriptSrc is ignored.
-   * @param scriptSrc    the actual script code (if any)
    * @param scriptLang   the scripting language
    * @param className    the extension class name 
    */
diff --git a/xalan/src/main/java/org/apache/xalan/lib/sql/JNDIConnectionPool.java b/xalan/src/main/java/org/apache/xalan/lib/sql/JNDIConnectionPool.java
index 3e32c7ab8..f874aa5c7 100644
--- a/xalan/src/main/java/org/apache/xalan/lib/sql/JNDIConnectionPool.java
+++ b/xalan/src/main/java/org/apache/xalan/lib/sql/JNDIConnectionPool.java
@@ -88,7 +88,7 @@ public JNDIConnectionPool(String jndiDatasourcePath)
   }
   
   /**
-   * Sets the path for the jndi datasource 
+   * Sets the path for the jndi datasource
    * @param jndiPath 
    */
   public void setJndiPath(String jndiPath)
@@ -97,8 +97,7 @@ public void setJndiPath(String jndiPath)
   }
 
   /**
-   * Returns the path for the jndi datasource 
-   * @param jndiPath 
+   * Returns the path for the jndi datasource
    */
   public String getJndiPath()
   {
@@ -108,8 +107,8 @@ public String getJndiPath()
   /**
    * Always returns true.
    * This method was intended to indicate if the pool was enabled, however, in
-   * this implementation that is not relavant.
-   * @return 
+   * this implementation that is not relevant.
+   * @return true
    */
   public boolean isEnabled()
   {
diff --git a/xalan/src/main/java/org/apache/xalan/lib/sql/SQLDocument.java b/xalan/src/main/java/org/apache/xalan/lib/sql/SQLDocument.java
index d88747907..84201fbeb 100644
--- a/xalan/src/main/java/org/apache/xalan/lib/sql/SQLDocument.java
+++ b/xalan/src/main/java/org/apache/xalan/lib/sql/SQLDocument.java
@@ -717,7 +717,6 @@ private void extractSQLMetaData( ResultSetMetaData meta )
   /**
    * Populate the Expanded Name Table with the Node that we will use.
    * Keep a reference of each of the types for access speed.
-   * @return
    */
   protected void createExpandedNameTable( )
   {
diff --git a/xalan/src/main/java/org/apache/xalan/lib/sql/SQLErrorDocument.java b/xalan/src/main/java/org/apache/xalan/lib/sql/SQLErrorDocument.java
index 43f0f8d32..c74e49fac 100644
--- a/xalan/src/main/java/org/apache/xalan/lib/sql/SQLErrorDocument.java
+++ b/xalan/src/main/java/org/apache/xalan/lib/sql/SQLErrorDocument.java
@@ -215,7 +215,6 @@ private void buildBasicStructure( Exception e )
   /**
    * Populate the Expanded Name Table with the Node that we will use.
    * Keep a reference of each of the types for access speed.
-   * @return
    */
   protected void createExpandedNameTable( )
   {
diff --git a/xalan/src/main/java/org/apache/xalan/lib/sql/XConnection.java b/xalan/src/main/java/org/apache/xalan/lib/sql/XConnection.java
index 0de079892..2ae0ac1cd 100644
--- a/xalan/src/main/java/org/apache/xalan/lib/sql/XConnection.java
+++ b/xalan/src/main/java/org/apache/xalan/lib/sql/XConnection.java
@@ -202,7 +202,7 @@ public XConnection( )
    * <code>org.apache.xalan.lib.sql.ConnectionPool</code> or a JNDI datasource.
    *
    * @param exprContext Context automatically passed from the XSLT sheet.
-   * @param name The name of the ConnectionPool or the JNDI DataSource path.
+   * @param connPoolName The name of the ConnectionPool or the JNDI DataSource path.
    *
    */
   public XConnection( ExpressionContext exprContext, String connPoolName )
diff --git a/xalan/src/main/java/org/apache/xalan/templates/ElemLiteralResult.java b/xalan/src/main/java/org/apache/xalan/templates/ElemLiteralResult.java
index 246fb0556..013106e33 100644
--- a/xalan/src/main/java/org/apache/xalan/templates/ElemLiteralResult.java
+++ b/xalan/src/main/java/org/apache/xalan/templates/ElemLiteralResult.java
@@ -266,7 +266,7 @@ public AVT getLiteralResultAttribute(String name)
   /**
    * Return the raw value of the attribute.
    *
-   * @param namespaceURI:localName or localName if the namespaceURI is null of 
+   * @param rawName Either "namespaceURI:localName" (or "localName" if the namespaceURI is null) of
    * the attribute to get
    *
    * @return The Attr value as a string, or the empty string if that attribute 
@@ -697,12 +697,12 @@ public Node removeNamedItemNS(String namespaceURI, String localName)
           /**
            * Unimplemented. See org.w3c.dom.NamedNodeMap
            *
-           * @param A node to store in this map
+           * @param arg A node to store in this map
            * 
            * @return If the new Node replaces an existing node the replaced 
            * Node is returned, otherwise null is returned
            *
-           * @throws DOMException
+           * @throws DOMException will be thrown as this method is not implemented
            */
           public Node setNamedItem(Node arg) throws DOMException
           {
@@ -714,12 +714,12 @@ public Node setNamedItem(Node arg) throws DOMException
           /**
            * Unimplemented. See org.w3c.dom.NamedNodeMap
            *
-           * @param A node to store in this map
+           * @param arg A node to store in this map
            * 
            * @return If the new Node replaces an existing node the replaced 
            * Node is returned, otherwise null is returned
            *
-           * @throws DOMException
+           * @throws DOMException will be thrown as this method is not implemented
            */
           public Node setNamedItemNS(Node arg) throws DOMException
           {
diff --git a/xalan/src/main/java/org/apache/xalan/templates/ElemNumber.java b/xalan/src/main/java/org/apache/xalan/templates/ElemNumber.java
index eaa2b7221..7feb47a97 100644
--- a/xalan/src/main/java/org/apache/xalan/templates/ElemNumber.java
+++ b/xalan/src/main/java/org/apache/xalan/templates/ElemNumber.java
@@ -585,8 +585,6 @@ public void execute(
    * @param newChild Child to add to child list
    *
    * @return Child just added to child list
-   *
-   * @throws DOMException
    */
   public ElemTemplateElement appendChild(ElemTemplateElement newChild)
   {
@@ -613,7 +611,7 @@ public ElemTemplateElement appendChild(ElemTemplateElement newChild)
    *
    * @return the first ancestor that matches the given pattern
    *
-   * @throws javax.xml.transform.TransformerException
+   * @throws javax.xml.transform.TransformerException if cannot get match score
    */
   int findAncestor(
           XPathContext xctxt, XPath fromMatchPattern, XPath countMatchPattern, 
@@ -1593,7 +1591,7 @@ String getZeroString()
    * @param val Value to convert -- must be greater than zero.
    * @param table a table containing one character for each digit in the radix
    * @return String representing alpha count of number.
-   * @see TransformerImpl#DecimalToRoman
+   * @see org.apache.xalan.transformer.DecimalToRoman
    *
    * Note that the radix of the conversion is inferred from the size
    * of the table.
@@ -1617,11 +1615,10 @@ protected String int2singlealphaCount(long val, CharArrayWrapper table)
    * count using the sequence A B C ... Z AA AB AC.... etc.
    * 
    * @param val Value to convert -- must be greater than zero.
-   * @param table a table containing one character for each digit in the radix
    * @param aTable Array of alpha characters representing numbers
    * @param stringBuf Buffer where to save the string representing alpha count of number.
    * 
-   * @see TransformerImpl#DecimalToRoman
+   * @see org.apache.xalan.transformer.DecimalToRoman
    *
    * Note that the radix of the conversion is inferred from the size
    * of the table.
@@ -1722,7 +1719,7 @@ protected void int2alphaCount(long val, CharArrayWrapper aTable,
    * @param thisBundle Resource bundle to use
    * 
    * @return String representing alpha count of number.
-   * @see XSLProcessor#DecimalToRoman
+   * @see org.apache.xalan.transformer.DecimalToRoman
    *
    * Note that the radix of the conversion is inferred from the size
    * of the table.
@@ -1933,7 +1930,7 @@ else if (val >= multiplier.getLong(i))
    * @param prefixesAreOK true_ to enable prefix notation (e.g. 4 = "IV"),
    * false_ to disable prefix notation (e.g. 4 = "IIII").
    * @return Roman numeral string.
-   * @see DecimalToRoman
+   * @see org.apache.xalan.transformer.DecimalToRoman
    * @see m_romanConvertTable
    */
   protected String long2roman(long val, boolean prefixesAreOK)
diff --git a/xalan/src/main/java/org/apache/xalan/transformer/NumeratorFormatter.java b/xalan/src/main/java/org/apache/xalan/transformer/NumeratorFormatter.java
index 97d025a34..89531243e 100644
--- a/xalan/src/main/java/org/apache/xalan/transformer/NumeratorFormatter.java
+++ b/xalan/src/main/java/org/apache/xalan/transformer/NumeratorFormatter.java
@@ -176,7 +176,7 @@ protected String int2alphaCount(int val, char[] table)
    * @param prefixesAreOK true_ to enable prefix notation (e.g. 4 = "IV"),
    * false_ to disable prefix notation (e.g. 4 = "IIII").
    * @return Roman numeral string.
-   * @see DecimalToRoman
+   * @see org.apache.xalan.transformer.DecimalToRoman
    * @see m_romanConvertTable
    */
   String long2roman(long val, boolean prefixesAreOK)
diff --git a/xalan/src/main/java/org/apache/xalan/transformer/TransformerImpl.java b/xalan/src/main/java/org/apache/xalan/transformer/TransformerImpl.java
index 62241afcc..a039e7fc4 100644
--- a/xalan/src/main/java/org/apache/xalan/transformer/TransformerImpl.java
+++ b/xalan/src/main/java/org/apache/xalan/transformer/TransformerImpl.java
@@ -798,9 +798,7 @@ public String getBaseURLOfSource()
   /**
    * Get the base URL of the source.
    *
-   *
    * NEEDSDOC @param base
-   * @return The base URL of the source tree, or null.
    */
   public void setBaseURLOfSource(String base)
   {
diff --git a/xalan/src/main/java/org/apache/xalan/xsltc/compiler/SyntaxTreeNode.java b/xalan/src/main/java/org/apache/xalan/xsltc/compiler/SyntaxTreeNode.java
index 54206b644..05890a9db 100644
--- a/xalan/src/main/java/org/apache/xalan/xsltc/compiler/SyntaxTreeNode.java
+++ b/xalan/src/main/java/org/apache/xalan/xsltc/compiler/SyntaxTreeNode.java
@@ -150,15 +150,14 @@ protected void setQName(QName qname) {
      * Set the QName for the SyntaxTreeNode
      * @param uri The element's namespace URI
      * @param prefix The element's namespace prefix
-     * @param local The element's local name
+     * @param localName The element's local name
      */
-    protected void setQName(String uri, String prefix, String localname) {
-	_qname = new QName(uri, prefix, localname);
+    protected void setQName(String uri, String prefix, String localName) {
+	_qname = new QName(uri, prefix, localName);
     }
 
     /**
-     * Set the QName for the SyntaxTreeNode
-     * @param qname The QName for the syntax tree node
+     * Get the QName for the SyntaxTreeNode
      */
     protected QName getQName() {
 	return(_qname);
@@ -916,7 +915,7 @@ protected final void indent(int indent) {
      * @param element The element in which the error occured (normally 'this'
      * but it could also be an expression/pattern/etc.)
      * @param parser The XSLT parser to report the error to.
-     * @param error The error code (from util/ErrorMsg).
+     * @param errorCode The error code (from util/ErrorMsg).
      * @param message Any additional error message.
      */
     protected void reportError(SyntaxTreeNode element, Parser parser,
@@ -930,7 +929,7 @@ protected void reportError(SyntaxTreeNode element, Parser parser,
      * @param element The element in which the error occured (normally 'this'
      * but it could also be an expression/pattern/etc.)
      * @param parser The XSLT parser to report the error to.
-     * @param error The error code (from util/ErrorMsg).
+     * @param errorCode The error code (from util/ErrorMsg).
      * @param message Any additional error message.
      */
     protected  void reportWarning(SyntaxTreeNode element, Parser parser,
diff --git a/xalan/src/main/java/org/apache/xalan/xsltc/compiler/util/MethodGenerator.java b/xalan/src/main/java/org/apache/xalan/xsltc/compiler/util/MethodGenerator.java
index 3a79066cc..d69615322 100644
--- a/xalan/src/main/java/org/apache/xalan/xsltc/compiler/util/MethodGenerator.java
+++ b/xalan/src/main/java/org/apache/xalan/xsltc/compiler/util/MethodGenerator.java
@@ -21,13 +21,7 @@
 
 package org.apache.xalan.xsltc.compiler.util;
 
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Hashtable;
-import java.util.Iterator;
-import java.util.Map;
-import java.util.Stack;
+import java.util.*;
 
 import org.apache.bcel.Constants;
 import org.apache.bcel.classfile.Field;
@@ -819,14 +813,13 @@ public int compareTo(Object comparand) {
     /**
      * Find the outlineable chunks in this method that would be the best choices
      * to outline, based on size and position in the method.
-     * @param classGen The {@link ClassGen} with which the generated methods
+     * @param classGen The {@link ClassGenerator} with which the generated methods
      *                 will be associated 
      * @param totalMethodSize the size of the bytecode in the original method
      * @return a <code>java.util.ArrayList</code> containing the
      *  {@link MethodGenerator.Chunk}s that may be outlined from this method
      */
-    private ArrayList getCandidateChunks(ClassGenerator classGen,
-                                         int totalMethodSize) {
+    private ArrayList getCandidateChunks(ClassGenerator classGen, int totalMethodSize) {
         Iterator instructions = getInstructionList().iterator();
         ArrayList candidateChunks = new ArrayList();
         ArrayList currLevelChunks = new ArrayList();
@@ -1125,7 +1118,7 @@ private ArrayList mergeAdjacentChunks(Chunk[] chunks) {
      * Breaks up the IL for this {@link MethodGenerator} into separate
      * outlined methods so that no method exceeds the 64KB limit on the length
      * of the byte code associated with a method. 
-     * @param classGen The {@link ClassGen} with which the generated methods
+     * @param classGen The {@link ClassGenerator} with which the generated methods
      *                 will be associated
      * @param originalMethodSize The number of bytes of bytecode represented by
      *                 the {@link InstructionList} of this method
@@ -1134,7 +1127,7 @@ private ArrayList mergeAdjacentChunks(Chunk[] chunks) {
      */
     public Method[] outlineChunks(ClassGenerator classGen,
                                   int originalMethodSize) {
-        ArrayList methodsOutlined = new ArrayList();
+        List<Method> methodsOutlined = new ArrayList<>();
         int currentMethodSize = originalMethodSize;
 
         int outlinedCount = 0;
@@ -1788,12 +1781,12 @@ private static Instruction loadLocal(int index, Type type) {
 
     /**
      * Helper method to generate an instance of a subclass of
-     * {@link StoreInstruction} based on the specified {@link Type} that will
+     * {@link Instruction} based on the specified {@link Type} that will
      * store a value in the specified local variable
      * @param index the JVM stack frame index of the variable that is to be
      * stored
      * @param type the {@link Type} of the variable
-     * @return the generated {@link StoredInstruction}
+     * @return the generated {@link Instruction}
      */
     private static Instruction storeLocal(int index, Type type) {
         if (type == Type.BOOLEAN) {
@@ -1973,7 +1966,7 @@ protected Method getThisMethod() {
      * </p>
      * @return <code>true</code> if the <code>InstructionList</code> was
      * modified; <code>false</code> otherwise
-     * @see The Java Virtual Machine Specification, Second Edition
+     * @see <a href="https://docs.oracle.com/javase/specs/jvms/se6/html/VMSpecTOC.doc.html">The Java Virtual Machine Specification, Second Edition</a>
      */
     boolean widenConditionalBranchTargetOffsets() {
         boolean ilChanged = false;