diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 86d30492f4a..3beddff37d1 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -180,6 +180,9 @@ Release 2.0.1-alpha - UNRELEASED
 
     HDFS-3243. TestParallelRead timing out on jenkins. (Henry Robinson via todd)
     
+    HDFS-3490. DatanodeWebHdfsMethods throws NullPointerException if
+    NamenodeRpcAddressParam is not set.  (szetszwo)
+
   BREAKDOWN OF HDFS-3042 SUBTASKS
 
     HDFS-2185. HDFS portion of ZK-based FailoverController (todd)
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/resources/DatanodeWebHdfsMethods.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/resources/DatanodeWebHdfsMethods.java
index 32b5c60cc6a..eb4afe75f85 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/resources/DatanodeWebHdfsMethods.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/resources/DatanodeWebHdfsMethods.java
@@ -98,6 +98,10 @@ public class DatanodeWebHdfsMethods {
       LOG.trace("HTTP " + op.getValue().getType() + ": " + op + ", " + path
           + ", ugi=" + ugi + Param.toSortedString(", ", parameters));
     }
+    if (nnRpcAddr == null) {
+      throw new IllegalArgumentException(NamenodeRpcAddressParam.NAME
+          + " is not specified.");
+    }
 
     //clear content type
     response.setContentType(null);
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java
index 0127e959be8..de8f256705b 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java
@@ -123,7 +123,7 @@ public class NamenodeWebHdfsMethods {
       final DelegationParam delegation,
       final UserParam username, final DoAsParam doAsUser,
       final UriFsPathParam path, final HttpOpParam<?> op,
-      final Param<?, ?>... parameters) throws IOException {
+      final Param<?, ?>... parameters) {
     if (LOG.isTraceEnabled()) {
       LOG.trace("HTTP " + op.getValue().getType() + ": " + op + ", " + path
           + ", ugi=" + ugi + ", " + username + ", " + doAsUser
@@ -532,7 +532,7 @@ public class NamenodeWebHdfsMethods {
           final RenewerParam renewer,
       @QueryParam(BufferSizeParam.NAME) @DefaultValue(BufferSizeParam.DEFAULT)
           final BufferSizeParam bufferSize
-      ) throws IOException, URISyntaxException, InterruptedException {
+      ) throws IOException, InterruptedException {
     return get(ugi, delegation, username, doAsUser, ROOT, op,
         offset, length, renewer, bufferSize);
   }
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/InetSocketAddressParam.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/InetSocketAddressParam.java
index dc21f684e7e..9879ba3032c 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/InetSocketAddressParam.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/InetSocketAddressParam.java
@@ -44,6 +44,10 @@ abstract class InetSocketAddressParam
 
     @Override
     InetSocketAddress parse(final String str) {
+      if (str == null) {
+        throw new IllegalArgumentException("The input string is null: expect "
+            + getDomain());
+      }
       final int i = str.indexOf(':');
       if (i < 0) {
         throw new IllegalArgumentException("Failed to parse \"" + str
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/LongParam.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/LongParam.java
index 023402cfe01..6f102e1c9f3 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/LongParam.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/LongParam.java
@@ -59,7 +59,7 @@ abstract class LongParam extends Param<Long, LongParam.Domain> {
 
     @Override
     public String getDomain() {
-      return "<" + NULL + " | short in radix " + radix + ">";
+      return "<" + NULL + " | long in radix " + radix + ">";
     }
 
     @Override
@@ -72,7 +72,7 @@ abstract class LongParam extends Param<Long, LongParam.Domain> {
       }
     }
 
-    /** Convert a Short to a String. */ 
+    /** Convert a Long to a String. */ 
     String toString(final Long n) {
       return n == null? NULL: Long.toString(n, radix);
     }
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestWebHdfsFileSystemContract.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestWebHdfsFileSystemContract.java
index 04ffd10b35d..61734180cfd 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestWebHdfsFileSystemContract.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestWebHdfsFileSystemContract.java
@@ -44,6 +44,7 @@ import org.apache.hadoop.hdfs.MiniDFSCluster;
 import org.apache.hadoop.hdfs.web.resources.DoAsParam;
 import org.apache.hadoop.hdfs.web.resources.GetOpParam;
 import org.apache.hadoop.hdfs.web.resources.HttpOpParam;
+import org.apache.hadoop.hdfs.web.resources.NamenodeRpcAddressParam;
 import org.apache.hadoop.hdfs.web.resources.PutOpParam;
 import org.apache.hadoop.security.AccessControlException;
 import org.apache.hadoop.security.UserGroupInformation;
@@ -351,5 +352,31 @@ public class TestWebHdfsFileSystemContract extends FileSystemContractBaseTest {
     {//test append.
       AppendTestUtil.testAppend(fs, new Path(dir, "append"));
     }
+
+    {//test NamenodeRpcAddressParam not set.
+      final HttpOpParam.Op op = PutOpParam.Op.CREATE;
+      final URL url = webhdfs.toUrl(op, dir);
+      HttpURLConnection conn = (HttpURLConnection) url.openConnection();
+      conn.setRequestMethod(op.getType().toString());
+      conn.setDoOutput(false);
+      conn.setInstanceFollowRedirects(false);
+      conn.connect();
+      final String redirect = conn.getHeaderField("Location");
+      conn.disconnect();
+
+      //remove NamenodeRpcAddressParam
+      WebHdfsFileSystem.LOG.info("redirect = " + redirect);
+      final int i = redirect.indexOf(NamenodeRpcAddressParam.NAME);
+      final int j = redirect.indexOf("&", i);
+      String modified = redirect.substring(0, i - 1) + redirect.substring(j);
+      WebHdfsFileSystem.LOG.info("modified = " + modified);
+
+      //connect to datanode
+      conn = (HttpURLConnection)new URL(modified).openConnection();
+      conn.setRequestMethod(op.getType().toString());
+      conn.setDoOutput(op.getDoOutput());
+      conn.connect();
+      assertEquals(HttpServletResponse.SC_BAD_REQUEST, conn.getResponseCode());
+    }
   }
 }