Revert "HADOOP-12584. Disable browsing the static directory in HttpServer2. Contributed by Robert Kanter."

This reverts commit b7e3f419bdaa4d46ffb9829dd7873b5221cab077.

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -1429,9 +1429,6 @@ Release 2.8.0 - UNRELEASED
     HADOOP-11901. BytesWritable fails to support 2G chunks due to integer
     overflow. (Reynold Xin via wheat9)
 
-    HADOOP-12584. Disable browsing the static directory in HttpServer2.
-    (Robert Kanter via wheat9)
-
 Release 2.7.3 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/http/HttpServer2.java

@@ -530,9 +530,6 @@ public final class HttpServer2 implements FilterContainer {
     staticContext.setResourceBase(appDir + "/static");
     staticContext.addServlet(DefaultServlet.class, "/*");
     staticContext.setDisplayName("static");
-    @SuppressWarnings("unchecked")
-    Map<String, String> params = staticContext.getInitParams();
-    params.put("org.mortbay.jetty.servlet.Default.dirAllowed", "false");
     setContextAttributes(staticContext, conf);
     defaultContexts.put(staticContext, true);
   }