Minor fixes such as:

advancedxy · advancedxy · commit f02bc1eefb9d · 2017-12-27T00:40:14.000+08:00
1. Update mima exclude
2. Update wording in TaskContext
3. Update JavaTaskContextCompileCheck as suggested in TaskContext note
diff --git a/core/src/main/scala/org/apache/spark/TaskContext.scala b/core/src/main/scala/org/apache/spark/TaskContext.scala
@@ -151,9 +151,10 @@ abstract class TaskContext extends Serializable {
   def stageId(): Int
 
   /**
-   * The attempt ID of the stage that this task belongs to.
+   * An ID that is unique to the stage attempt that this task belongs to.
    */
   def stageAttemptId(): Int
+
   /**
    * The ID of the RDD partition that is computed by this task.
    */
diff --git a/core/src/test/java/test/org/apache/spark/JavaTaskContextCompileCheck.java b/core/src/test/java/test/org/apache/spark/JavaTaskContextCompileCheck.java
@@ -38,6 +38,7 @@ public static void test() {
     tc.attemptNumber();
     tc.partitionId();
     tc.stageId();
+    tc.stageAttemptId();
     tc.taskAttemptId();
   }
 
@@ -51,6 +52,7 @@ public void onTaskCompletion(TaskContext context) {
       context.isCompleted();
       context.isInterrupted();
       context.stageId();
+      context.stageAttemptId();
       context.partitionId();
       context.addTaskCompletionListener(this);
     }
diff --git a/project/MimaExcludes.scala b/project/MimaExcludes.scala
@@ -95,7 +95,10 @@ object MimaExcludes {
 
     // [SPARK-21087] CrossValidator, TrainValidationSplit expose sub models after fitting: Scala
     ProblemFilters.exclude[FinalClassProblem]("org.apache.spark.ml.tuning.CrossValidatorModel$CrossValidatorModelWriter"),
-    ProblemFilters.exclude[FinalClassProblem]("org.apache.spark.ml.tuning.TrainValidationSplitModel$TrainValidationSplitModelWriter")
+    ProblemFilters.exclude[FinalClassProblem]("org.apache.spark.ml.tuning.TrainValidationSplitModel$TrainValidationSplitModelWriter"),
+
+    // [SPARK-22897] Expose stageAttemptId in TaskContext
+    ProblemFilters.exclude[ReversedMissingMethodProblem]("org.apache.spark.TaskContext.stageAttemptId")
   )
 
   // Exclude rules for 2.2.x

Original file line number	Diff line number	Diff line change
`@@ -38,6 +38,7 @@ public static void test() {`
`38`	`38`	`tc.attemptNumber();`
`39`	`39`	`tc.partitionId();`
`40`	`40`	`tc.stageId();`
	`41`	`+ tc.stageAttemptId();`
`41`	`42`	`tc.taskAttemptId();`
`42`	`43`	`}`
`43`	`44`
`@@ -51,6 +52,7 @@ public void onTaskCompletion(TaskContext context) {`
`51`	`52`	`context.isCompleted();`
`52`	`53`	`context.isInterrupted();`
`53`	`54`	`context.stageId();`
	`55`	`+ context.stageAttemptId();`
`54`	`56`	`context.partitionId();`
`55`	`57`	`context.addTaskCompletionListener(this);`
`56`	`58`	`}`