svn merge -c 1311479 from trunk. FIXES: MAPREDUCE-4117. mapred job -status throws NullPointerException (Devaraj K via bobby)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1311480 13f79535-47bb-0310-9956-ffa450edef68

hadoop-mapreduce-project/CHANGES.txt

@@ -181,6 +181,9 @@ Release 0.23.3 - UNRELEASED
     MAPREDUCE-4051. Remove the empty hadoop-mapreduce-project/assembly/all.xml
     file (Ravi Prakash via bobby)
 
+    MAPREDUCE-4117. mapred job -status throws NullPointerException (Devaraj K
+    via bobby)
+
 Release 0.23.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/Job.java

@@ -509,6 +509,11 @@ public class Job extends JobContextImpl implements JobContext {
         lastEvent = event;
       }
     }
+    if (lastEvent == null) {
+      return "There are no failed tasks for the job. "
+          + "Job is failed due to some other reason and reason "
+          + "can be found in the logs.";
+    }
     String[] taskAttemptID = lastEvent.getTaskAttemptId().toString().split("_", 2);
     String taskID = taskAttemptID[1].substring(0, taskAttemptID[1].length()-2);
     return (" task " + taskID + " failed " +

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/test/java/org/apache/hadoop/mapreduce/TestJob.java

@@ -0,0 +1,53 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.mapreduce;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.io.IOException;
+
+import org.apache.hadoop.mapred.JobConf;
+import org.apache.hadoop.mapreduce.JobStatus.State;
+import org.apache.hadoop.mapreduce.protocol.ClientProtocol;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TestJob {
+  @Test
+  public void testJobToString() throws IOException, InterruptedException {
+    Cluster cluster = mock(Cluster.class);
+    ClientProtocol client = mock(ClientProtocol.class);
+    when(cluster.getClient()).thenReturn(client);
+    JobID jobid = new JobID("1014873536921", 6);
+    JobStatus status = new JobStatus(jobid, 0.0f, 0.0f, 0.0f, 0.0f,
+        State.FAILED, JobPriority.NORMAL, "root", "TestJobToString",
+        "job file", "tracking url");
+    when(client.getJobStatus(jobid)).thenReturn(status);
+    when(client.getTaskReports(jobid, TaskType.MAP)).thenReturn(
+        new TaskReport[0]);
+    when(client.getTaskReports(jobid, TaskType.REDUCE)).thenReturn(
+        new TaskReport[0]);
+    when(client.getTaskCompletionEvents(jobid, 0, 10)).thenReturn(
+        new TaskCompletionEvent[0]);
+    Job job = Job.getInstance(cluster, status, new JobConf());
+    Assert.assertNotNull(job.toString());
+  }
+
+}