{{{
#!java
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.StringTokenizer;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.filecache.DistributedCache;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.StringUtils;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

public class WordCountV020 extends Configured implements Tool {

	static Set<String> patternsToSkip = new HashSet<String>();

	static void parseSkipFile(Path patternsFile) {
		try {
			BufferedReader fis = new BufferedReader(new FileReader(patternsFile
					.toString()));
			String pattern = null;
			while ((pattern = fis.readLine()) != null) {
				patternsToSkip.add(pattern);
			}
		} catch (IOException ioe) {
			System.err
					.println("Caught exception while parsing the cached file '"
							+ patternsFile + "' : "
							+ StringUtils.stringifyException(ioe));
		}
	}

	public static class Map extends
			Mapper<LongWritable, Text, Text, IntWritable> {

		static enum Counters {
			INPUT_WORDS
		}

		boolean caseSensitive;

		private final static IntWritable one = new IntWritable(1);
		private Text word = new Text();

		public void setup(Context context) {
			Configuration conf = context.getConfiguration();
			caseSensitive = conf.getBoolean("wordcount.case.sensitive", true);
		}

		public void map(LongWritable key, Text value, Context context)
				throws IOException, InterruptedException {

			String line = (caseSensitive) ? value.toString() : value.toString()
					.toLowerCase();

			for (String pattern : patternsToSkip) {
				line = line.replaceAll(pattern, "");
			}

			StringTokenizer tokenizer = new StringTokenizer(line);
			while (tokenizer.hasMoreTokens()) {
				word.set(tokenizer.nextToken());
				context.write(word, one);

			}

		}
	}

	public static class Reduce extends
			Reducer<Text, IntWritable, Text, IntWritable> {
		public void reduce(Text key, Iterator<IntWritable> values,
				Context context) throws IOException, InterruptedException {
			int sum = 0;
			while (values.hasNext()) {
				sum += values.next().get();
			}
			context.write(key, new IntWritable(sum));
		}
	}

	public int run(String[] args) throws Exception {

		Configuration conf = new Configuration();
		// 宣告job 取得conf 並設定名稱 Hadoop Hello World
		Job job = new Job(conf, "Hadoop Hello World");
		// 設定此運算的主程式
		job.setJarByClass(WordCountV020.class);

		job.setOutputKeyClass(Text.class);
		job.setOutputValueClass(IntWritable.class);

		job.setMapperClass(Map.class);
		job.setCombinerClass(Reduce.class);
		job.setReducerClass(Reduce.class);

		List<String> other_args = new ArrayList<String>();

		for (int i = 0; i < args.length; ++i) {
			if ("-skip".equals(args[i])) {
				DistributedCache
						.addCacheFile(new Path(args[++i]).toUri(), conf);
				conf.setBoolean("wordcount.skip.patterns", true);
			} else {
				other_args.add(args[i]);
			}
		}

		Path[] patternsFiles = null;
		if (conf.getBoolean("wordcount.skip.patterns", false)) {

			try {
				patternsFiles = DistributedCache.getLocalCacheFiles(conf);

			} catch (Exception ioe) {
				System.err
						.println("Caught exception while getting cached files: "
								+ StringUtils.stringifyException(ioe));
			}
			if (patternsFiles != null) {

				for (Path patternsFile : patternsFiles) {
					System.err.println(patternsFile);
					parseSkipFile(patternsFile);
				}
			} else {
				System.err.print("no path");
			}

		}

		FileInputFormat.setInputPaths(job, new Path(other_args.get(0)));
		// 設定輸出路徑
		FileOutputFormat.setOutputPath(job, new Path(other_args.get(1)));

		// CheckAndDelete.checkAndDelete(other_args.get(1), conf);
		job.waitForCompletion(true);
		return 0;
	}

	public static void main(String[] args) throws Exception {
		String[] argv = { "-Dwordcount.case.sensitive=false",
				"/user/waue/input", "/user/waue/output-v020", "-skip",
				"/user/waue/patterns" };
		args = argv;
		int res = ToolRunner
				.run(new Configuration(), new WordCountV020(), args);
		System.exit(res);
	}
}
}}}

{{{
10/04/16 10:17:05 WARN conf.Configuration: DEPRECATED: hadoop-site.xml found in the classpath. Usage of hadoop-site.xml is deprecated. Instead use core-site.xml, mapred-site.xml and hdfs-site.xml to override properties of core-default.xml, mapred-default.xml and hdfs-default.xml respectively
no path10/04/16 10:17:05 WARN mapred.JobClient: Use GenericOptionsParser for parsing the arguments. Applications should implement Tool for the same.
10/04/16 10:17:06 INFO input.FileInputFormat: Total input paths to process : 4
10/04/16 10:17:06 INFO mapred.JobClient: Running job: job_201003231850_0008
10/04/16 10:17:07 INFO mapred.JobClient:  map 0% reduce 0%
10/04/16 10:17:14 INFO mapred.JobClient: Task Id : attempt_201003231850_0008_m_000005_0, Status : FAILED
java.io.IOException: Task process exit with nonzero status of 126.
	at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:418)

10/04/16 10:17:14 WARN mapred.JobClient: Error reading task outputhttp://vpro:50060/tasklog?plaintext=true&taskid=attempt_201003231850_0008_m_000005_0&filter=stdout
10/04/16 10:17:14 WARN mapred.JobClient: Error reading task outputhttp://vpro:50060/tasklog?plaintext=true&taskid=attempt_201003231850_0008_m_000005_0&filter=stderr
}}}