YARN-5804. New UI2 is not able to launch with jetty 9 upgrade post HADOOP-10075. (Sunil G via wangda)

(cherry picked from commit ddebaa6b7ae1031899139d153d57df5387d60542)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/webapp/WebApps.java

@@ -43,7 +43,7 @@ import org.apache.hadoop.security.http.RestCsrfPreventionFilter;
 import org.apache.hadoop.security.http.XFrameOptionsFilter;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.webapp.util.WebAppUtils;
-import org.mortbay.jetty.webapp.WebAppContext;
+import org.eclipse.jetty.webapp.WebAppContext;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -377,7 +377,7 @@ public class WebApps {
       WebApp webApp = build(webapp);
       HttpServer2 httpServer = webApp.httpServer();
       if (ui2Context != null) {
-        httpServer.addContext(ui2Context, true);
+        httpServer.addHandlerAtFront(ui2Context);
       }
       try {
         httpServer.start();

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/ResourceManager.java

@@ -115,7 +115,7 @@ import org.apache.hadoop.yarn.webapp.WebApps;
 import org.apache.hadoop.yarn.webapp.WebApps.Builder;
 import org.apache.hadoop.yarn.webapp.util.WebAppUtils;
 import org.apache.zookeeper.server.auth.DigestAuthenticationProvider;
-import org.mortbay.jetty.webapp.WebAppContext;
+import org.eclipse.jetty.webapp.WebAppContext;
 
 import com.google.common.annotations.VisibleForTesting;
 import java.io.IOException;