checkstyle.org has https site

check.xml

@@ -23,7 +23,7 @@
     and Nu Html Checker (v.Nu).
 
     Checkstyle uses an abstract syntax tree (AST) for doing checks
-    against Java sources. It is available at http://checkstyle.sourceforge.net/
+    against Java sources. It is available at https://checkstyle.org/
     under GPL 2.1 license.
 
     "Apache Rat is a release audit tool, focused on licenses." It is available

manual/tutorial-tasks-filesets-properties.html

@@ -781,7 +781,7 @@ run <kbd>ant test</kbd> (like above).</p>
 the <a href="https://ant.apache.org/ant_task_guidelines.html" target="_top">Ant Task Guidelines [6]</a> which includes
 the <a href="https://www.oracle.com/technetwork/java/codeconvtoc-136057.html" target="_top">Sun code style
 [9]</a>). Because there are so many things we would be happy to have a tool for do the checks.  There is one:
-checkstyle. Checkstyle is available at <a href="http://checkstyle.sourceforge.net/" target="_top">Sourceforge [10]</a>
+checkstyle. Checkstyle is available at <a href="https://checkstyle.org/" target="_top">Sourceforge [10]</a>
 and Ant provides with the <samp>check.xml</samp> a buildfile which will do the job for us.</p>
 
 <p>Download it and put the <samp>checkstyle-*-all.jar</samp> into your <samp>%USERPROFILE%\.ant\lib</samp> directory.
@@ -866,7 +866,7 @@ and the steps described there if you haven't one.</p>
            target="_top">https://www.oracle.com/technetwork/java/archive-139210.html</a></li>
     <li><a href="https://www.oracle.com/technetwork/java/codeconvtoc-136057.html"
            target="_top">https://www.oracle.com/technetwork/java/codeconvtoc-136057.html</a></li>
-    <li><a href="http://checkstyle.sourceforge.net/" target="_top">http://checkstyle.sourceforge.net/</a></li>
+    <li><a href="https://checkstyle.org/" target="_top">https://checkstyle.org/</a></li>
     <li><a href="https://issues.apache.org/bugzilla/" target="_top">https://issues.apache.org/bugzilla/</a></li>
     <li><a href="https://issues.apache.org/bugzilla/createaccount.cgi"
            target="_top">https://issues.apache.org/bugzilla/createaccount.cgi</a></li>