HADOOP-4620. Adding PipeMapRunner.java that I missed earlier.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/core/trunk@725910 13f79535-47bb-0310-9956-ffa450edef68

src/contrib/streaming/src/java/org/apache/hadoop/streaming/PipeMapRunner.java

@@ -0,0 +1,38 @@
+/**
+ * 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.streaming;
+
+import org.apache.hadoop.mapred.MapRunner;
+import org.apache.hadoop.mapred.Reporter;
+import org.apache.hadoop.mapred.RecordReader;
+import org.apache.hadoop.mapred.OutputCollector;
+
+import java.io.IOException;
+
+import org.apache.hadoop.util.ReflectionUtils;
+
+public class PipeMapRunner<K1, V1, K2, V2> extends MapRunner<K1, V1, K2, V2> {
+  public void run(RecordReader<K1, V1> input, OutputCollector<K2, V2> output,
+                  Reporter reporter)
+         throws IOException {
+    PipeMapper pipeMapper = (PipeMapper)getMapper();
+    pipeMapper.startOutputThreads(output, reporter);
+    super.run(input, output, reporter);
+  }
+}