HDFS-4367. Merge change 1429199 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1431462 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -10,6 +10,9 @@ Release 2.0.3-alpha - Unreleased
     HDFS-4362. GetDelegationTokenResponseProto does not handle null token.
     (suresh)
 
+    HDFS-4367. GetDataEncryptionKeyResponseProto does not handle null
+    response. (suresh)
+
   NEW FEATURES
 
     HDFS-2656. Add libwebhdfs, a pure C client based on WebHDFS.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolServerSideTranslatorPB.java

@@ -839,10 +839,13 @@ public class ClientNamenodeProtocolServerSideTranslatorPB implements
       RpcController controller, GetDataEncryptionKeyRequestProto request)
       throws ServiceException {
     try {
+      GetDataEncryptionKeyResponseProto.Builder builder = 
+          GetDataEncryptionKeyResponseProto.newBuilder();
       DataEncryptionKey encryptionKey = server.getDataEncryptionKey();
-      return GetDataEncryptionKeyResponseProto.newBuilder()
-          .setDataEncryptionKey(PBHelper.convert(encryptionKey))
-          .build();
+      if (encryptionKey != null) {
+        builder.setDataEncryptionKey(PBHelper.convert(encryptionKey));
+      }
+      return builder.build();
     } catch (IOException e) {
       throw new ServiceException(e);
     }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolTranslatorPB.java

@@ -64,6 +64,7 @@ import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.GetDat
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.GetBlockLocationsRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.GetBlockLocationsResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.GetContentSummaryRequestProto;
+import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.GetDataEncryptionKeyResponseProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.GetDatanodeReportRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.GetDelegationTokenRequestProto;
 import org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos.GetDelegationTokenResponseProto;
@@ -111,7 +112,6 @@ import org.apache.hadoop.ipc.ProtocolMetaInterface;
 import org.apache.hadoop.ipc.RPC;
 import org.apache.hadoop.ipc.RpcClientUtil;
 import org.apache.hadoop.security.AccessControlException;
-import org.apache.hadoop.security.proto.SecurityProtos.TokenProto;
 import org.apache.hadoop.security.token.Token;
 
 import com.google.protobuf.ByteString;
@@ -819,8 +819,10 @@ public class ClientNamenodeProtocolTranslatorPB implements
     GetDataEncryptionKeyRequestProto req = GetDataEncryptionKeyRequestProto
         .newBuilder().build();
     try {
-      return PBHelper.convert(rpcProxy.getDataEncryptionKey(null, req)
-          .getDataEncryptionKey());
+      GetDataEncryptionKeyResponseProto rsp = 
+          rpcProxy.getDataEncryptionKey(null, req);
+      return rsp.hasDataEncryptionKey() ? 
+          PBHelper.convert(rsp.getDataEncryptionKey()) : null;
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
     }

hadoop-hdfs-project/hadoop-hdfs/src/main/proto/ClientNamenodeProtocol.proto

@@ -443,7 +443,7 @@ message GetDataEncryptionKeyRequestProto { // no parameters
 }
 
 message GetDataEncryptionKeyResponseProto {
-  required DataEncryptionKeyProto dataEncryptionKey = 1;
+  optional DataEncryptionKeyProto dataEncryptionKey = 1;
 }
 
 service ClientNamenodeProtocol {