use ConcurrentHashMap

Author: rbri

src/main/java/org/htmlunit/css/CssColors.java

@@ -14,9 +14,9 @@
  */
 package org.htmlunit.css;
 
-import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * Helper to work with colors.
@@ -25,7 +25,7 @@
  */
 public final class CssColors {
 
-    private static final Map<String, String> CSS_COLORS = new HashMap<>();
+    private static final Map<String, String> CSS_COLORS = new ConcurrentHashMap<>();
 
     static {
         CSS_COLORS.put("aqua", "rgb(0, 255, 255)");

src/main/java/org/htmlunit/css/StyleAttributes.java

@@ -32,9 +32,9 @@
 
 import java.io.Serializable;
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 import org.htmlunit.BrowserVersion;
 
@@ -48,7 +48,7 @@
  */
 @SuppressWarnings("PMD.AvoidDuplicateLiterals")
 public final class StyleAttributes implements Serializable {
-    private static final Map<String, Definition> STYLES = new HashMap<>();
+    private static final Map<String, Definition> STYLES = new ConcurrentHashMap<>();
 
     static {
         for (final Definition definition : Definition.values()) {

src/main/java/org/htmlunit/html/parser/neko/HtmlUnitNekoHtmlParser.java

@@ -21,9 +21,9 @@
 import java.net.URL;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 import org.htmlunit.ObjectInstantiationException;
 import org.htmlunit.Page;
@@ -73,7 +73,7 @@ public final class HtmlUnitNekoHtmlParser implements HTMLParser {
      */
     public static final SvgElementFactory SVG_FACTORY = new SvgElementFactory();
 
-    private static final Map<String, ElementFactory> ELEMENT_FACTORIES = new HashMap<>();
+    private static final Map<String, ElementFactory> ELEMENT_FACTORIES = new ConcurrentHashMap<>();
 
     static {
         final DefaultElementFactory defaultElementFactory = new DefaultElementFactory();

src/main/java/org/htmlunit/svg/SvgElementFactory.java

@@ -14,9 +14,9 @@
  */
 package org.htmlunit.svg;
 
-import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 import org.htmlunit.SgmlPage;
 import org.htmlunit.html.DomAttr;
@@ -53,7 +53,7 @@ public class SvgElementFactory implements ElementFactory {
         SvgTitle.class, SvgTRef.class, SvgTSpan.class, SvgUse.class, SvgView.class, SvgVKern.class
     };
 
-    private static final Map<String, Class<?>> ELEMENTS_ = new HashMap<>();
+    private static final Map<String, Class<?>> ELEMENTS_ = new ConcurrentHashMap<>();
 
     static {
         try {