HADOOP-11005. Fix HTTP content type for ReconfigurationServlet. Contributed by Lei Xu.

(cherry picked from commit 7119bd49c870cf1e6b8c091d87025b439b9468df)

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

@@ -140,6 +140,9 @@ Release 2.6.0 - UNRELEASED
     HADOOP-10880. Move HTTP delegation tokens out of URL querystring to 
     a header. (tucu)
 
+    HADOOP-11005. Fix HTTP content type for ReconfigurationServlet.
+    (Lei Xu via wang)
+
   OPTIMIZATIONS
 
     HADOOP-10838. Byte array native checksumming. (James Thomas via todd)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/ReconfigurationServlet.java

@@ -200,6 +200,7 @@ public class ReconfigurationServlet extends HttpServlet {
   protected void doGet(HttpServletRequest req, HttpServletResponse resp)
     throws ServletException, IOException {
     LOG.info("GET");
+    resp.setContentType("text/html");
     PrintWriter out = resp.getWriter();
     
     Reconfigurable reconf = getReconfigurable(req);
@@ -214,6 +215,7 @@ public class ReconfigurationServlet extends HttpServlet {
   protected void doPost(HttpServletRequest req, HttpServletResponse resp)
     throws ServletException, IOException {
     LOG.info("POST");
+    resp.setContentType("text/html");
     PrintWriter out = resp.getWriter();
 
     Reconfigurable reconf = getReconfigurable(req);