Fix ClassCastException in JobHistoryServer for certain jobs. (Siddharth Seth via llu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/MR-279@1135879 13f79535-47bb-0310-9956-ffa450edef68

mapreduce/CHANGES.txt

@@ -5,6 +5,9 @@ Trunk (unreleased changes)
 
     MAPREDUCE-279
 
+    Fix ClassCastException in JobHistoryServer for certain jobs.
+    (Siddharth Seth via llu)
+
     MAPREDUCE-2569. Ensure root queue allocated 100% capacity. (Jonathan
     Eagles via cdouglas)
 

mapreduce/mr-client/hadoop-mapreduce-client-hs/src/main/java/org/apache/hadoop/mapreduce/v2/hs/JobHistory.java

@@ -527,7 +527,7 @@ public class JobHistory extends AbstractService implements HistoryContext   {
    */
   private MetaInfo scanOldDirsForJob(JobId jobId) throws IOException {
     int jobSerialNumber = JobHistoryUtils.jobSerialNumber(jobId);
-    Integer boxedSerialNumber = jobSerialNumber;
+    String boxedSerialNumber = String.valueOf(jobSerialNumber);
     Set<String> dateStringSet = idToDateString.get(boxedSerialNumber);
     if (dateStringSet == null) {
       return null;