addendum - fix webhdfs

Author: virajjasani

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/ExceptionHandler.java

@@ -109,6 +109,29 @@ public Response toResponse(Exception e) {
       s = Response.Status.BAD_REQUEST;
     } else if (e instanceof IllegalArgumentException) {
       s = Response.Status.BAD_REQUEST;
+    } else if (e != null && e.getCause() != null) {
+      if (e.getCause() instanceof SecurityException) {
+        s = Response.Status.FORBIDDEN;
+        e = (Exception) e.getCause();
+      } else if (e.getCause() instanceof AuthorizationException) {
+        s = Response.Status.FORBIDDEN;
+        e = (Exception) e.getCause();
+      } else if (e.getCause() instanceof FileNotFoundException) {
+        s = Response.Status.NOT_FOUND;
+        e = (Exception) e.getCause();
+      } else if (e.getCause() instanceof IOException) {
+        s = Response.Status.FORBIDDEN;
+        e = (Exception) e.getCause();
+      } else if (e.getCause() instanceof UnsupportedOperationException) {
+        s = Response.Status.BAD_REQUEST;
+        e = (Exception) e.getCause();
+      } else if (e.getCause() instanceof IllegalArgumentException) {
+        s = Response.Status.BAD_REQUEST;
+        e = (Exception) e.getCause();
+      } else {
+        LOG.warn("INTERNAL_SERVER_ERROR", e);
+        s = Response.Status.INTERNAL_SERVER_ERROR;
+      }
     } else {
       LOG.warn("INTERNAL_SERVER_ERROR", e);
       s = Response.Status.INTERNAL_SERVER_ERROR;