Java tutorial
/** * 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.oozie.action.hadoop; import org.apache.hadoop.mapred.Counters; import org.apache.hadoop.mapred.Mapper; import org.apache.hadoop.mapred.OutputCollector; import org.apache.hadoop.mapred.Reporter; import org.apache.hadoop.mapred.JobConf; import org.apache.hadoop.mapred.Reducer; import org.apache.hadoop.mapred.RunningJob; import java.io.IOException; import java.util.Iterator; @SuppressWarnings("deprecation") public class MapperReducerCredentialsForTest implements Mapper, Reducer { public static final String COUNTER_GROUP = "cg"; public static final String COUNTER_OUTPUT_DATA = "cod"; public static final String TEST_CRED = "testcred"; String credential = null; public static void main(String[] args) { System.out.println("hello!"); } public void configure(JobConf jobConf) { credential = jobConf.get(TEST_CRED); } public void close() throws IOException { } @SuppressWarnings("unchecked") public void map(Object key, Object value, OutputCollector collector, Reporter reporter) throws IOException { collector.collect(key, value); if (credential != null) { reporter.incrCounter(COUNTER_GROUP, COUNTER_OUTPUT_DATA, 1); } } @SuppressWarnings("unchecked") public void reduce(Object key, Iterator values, OutputCollector collector, Reporter reporter) throws IOException { while (values.hasNext()) { collector.collect(key, values.next()); } } public static boolean hasCredentials(RunningJob runningJob) throws IOException { boolean output = false; Counters counters = runningJob.getCounters(); if (counters != null) { Counters.Group group = counters.getGroup(COUNTER_GROUP); if (group != null) { output = group.getCounter(COUNTER_OUTPUT_DATA) > 0; } } return output; } }