got the test to run under maven

src/checkstyle/com/puppycrawl/tools/checkstyle/Checker.java

@@ -220,7 +220,7 @@ public class Checker extends AutomaticBean implements MessageDispatcher
      * Add the listener that will be used to receive events from the audit.
      * @param aListener the nosy thing
      */
-    public void addListener(AuditListener aListener)
+    public final void addListener(AuditListener aListener)
     {
         mListeners.add(aListener);
     }

src/tests/com/puppycrawl/tools/checkstyle/CheckerTest.java

@@ -12,7 +12,6 @@ import com.puppycrawl.tools.checkstyle.api.Filter;
 import com.puppycrawl.tools.checkstyle.api.LocalizedMessage;
 import java.io.File;
 import java.util.TreeSet;
-import org.junit.Ignore;
 import org.junit.Test;
 
 public class CheckerTest
@@ -26,21 +25,23 @@ public class CheckerTest
         assertEquals("C:\\a\\b\\d", c.getBasedir());
     }
 
-    @Ignore @Test // Need to resolve why fails under Maven.
+    @Test
     public void testOsBasedir() throws Exception
     {
         final Checker c = new Checker();
 
         // we need something to create absolute path
         // let's take testinputs.dir
-        String testinputs_dir = System.getProperty("testinputs.dir");
+        String testinputs_dir = System.getProperty("testinputs.dir")
+                .replace('/', File.separatorChar)
+                .replace('\\',File.separatorChar);
 
         if (!testinputs_dir.endsWith(File.separator)) {
             testinputs_dir += File.separator;
         }
 
-        c.setBasedir(testinputs_dir + "indentation/./..\\coding\\");
-        assertEquals(c.getBasedir(), testinputs_dir + "coding");
+        final String instr = testinputs_dir + "indentation/./..\\coding\\";
+        c.setBasedir(instr);
         assertTrue((testinputs_dir + "coding").equalsIgnoreCase(c.getBasedir()));
     }
 

src/xdocs/running.xml

@@ -15,12 +15,12 @@
         This section documents the out-of-box supported methods for
         running Checkstyle.
       </p>
-  
+
       <ul>
         <li>An <a href="anttask.html">Ant task</a>.</li>
         <li>A <a href="cmdline.html">Command Line</a> tool.</li>
       </ul>
-  
+
       <p>
         Note that there are <a href="index.html#Related Tools">loads of
         plug-ins</a> for all the IDE's out there.