Since it wasn't really described how exactly did you resolve it... The point is that on the client side (it's important that it's not on the server side), set "dfs.datanode.use.datanode.hostname" in the org.apache.hadoop.conf.Configuration object to value "true". If the Configuration object isn't created by your code (like if Spark creates it, in my case), then it depends on what creates it... see its documentation. But some guesses:
Attempt 1: Set it inside $HADOOP_HOME/etc/hadoop/hdfs-site.xml. Hadoop command line tools use that, your Java application though... maybe not.
Attempt 2: Put $HADOOP_HOME/etc/hadoop/ into the Java classpath (or pack hdfs-site.xml into your project under /src/main/resources/, but that's kind of dirty...). This works with Spark.