8277536: Use String.blank in jdk.javadoc where applicable

Reviewed-by: jjg

src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/HtmlDocletWriter.java

@@ -896,7 +896,7 @@ public Content getDocLink(HtmlLinkInfo.Kind context, Element element, CharSequen
      * Return the link for the given member.
      *
      * @param context the id of the context where the link will be printed.
-     * @param typeElement the typeElement that we should link to. This is not
+     * @param typeElement the typeElement that we should link to. This is
      *            not necessarily the type containing element since we may be
      *            inheriting comments.
      * @param element the member being linked to.
@@ -912,7 +912,7 @@ public Content getDocLink(HtmlLinkInfo.Kind context, TypeElement typeElement, El
      * Return the link for the given member.
      *
      * @param context the id of the context where the link will be printed.
-     * @param typeElement the typeElement that we should link to. This is not
+     * @param typeElement the typeElement that we should link to. This is
      *            not necessarily the type containing element since we may be
      *            inheriting comments.
      * @param element the member being linked to.
@@ -929,7 +929,7 @@ public Content getDocLink(HtmlLinkInfo.Kind context, TypeElement typeElement, El
      * Return the link for the given member.
      *
      * @param context the id of the context where the link will be printed.
-     * @param typeElement the typeElement that we should link to. This is not
+     * @param typeElement the typeElement that we should link to. This is
      *            not necessarily the type containing element since we may be
      *            inheriting comments.
      * @param element the member being linked to.
@@ -945,7 +945,7 @@ public Content getDocLink(HtmlLinkInfo.Kind context, TypeElement typeElement, El
      * Return the link for the given member.
      *
      * @param context the id of the context where the link will be printed.
-     * @param typeElement the typeElement that we should link to. This is not
+     * @param typeElement the typeElement that we should link to. This is
      *            not necessarily the type containing element since we may be
      *            inheriting comments.
      * @param element the member being linked to.
@@ -1407,14 +1407,6 @@ boolean ignoreNonInlineTag(DocTree dtree) {
         return false;
     }
 
-    boolean isAllWhiteSpace(String body) {
-        for (int i = 0 ; i < body.length(); i++) {
-            if (!Character.isWhitespace(body.charAt(i)))
-                return false;
-        }
-        return true;
-    }
-
     // Notify the next DocTree handler to take necessary action
     private boolean commentRemoved = false;
 
@@ -1505,7 +1497,7 @@ public ContentBuilder add(CharSequence text) {
                 // Ignore any trailing whitespace OR whitespace after removed html comment
                 if ((isLastNode || commentRemoved)
                         && tag.getKind() == TEXT
-                        && isAllWhiteSpace(ch.getText(tag)))
+                        && ch.getText(tag).isBlank())
                     continue;
 
                 // Ignore any leading html comments

src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclint/Checker.java

@@ -1236,13 +1236,7 @@ void warnIfEmpty(DocTree tree, List<? extends DocTree> list) {
     }
 
     boolean hasNonWhitespace(TextTree tree) {
-        String s = tree.getBody();
-        for (int i = 0; i < s.length(); i++) {
-            Character c = s.charAt(i);
-            if (!Character.isWhitespace(s.charAt(i)))
-                return true;
-        }
-        return false;
+        return !tree.getBody().isBlank();
     }
 
     // </editor-fold>