hadoop对专利引用数据进行处理，输出被引用的专利

对有如下专利数据

进行处理，把每个专利被引用的专利输出，代码如下

package com.hadoop.test;

import java.io.IOException;
import java.util.Iterator;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.KeyValueTextInputFormat;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.TextOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

/**
 * 对专利数据集进行处理，一个专利输出所有的引用的专利
 * 
 * @author root 2014-12-28
 */
public class MyJob extends Configured implements Tool {

	public static class MapClass extends MapReduceBase implements
			Mapper {

		@Override
		public void map(Text key, Text value,
				OutputCollector output, Reporter reporter)
				throws IOException {
			// TODO Auto-generated method stub
			output.collect(value, key);
		}

	}

	public static class Reduce extends MapReduceBase implements
			Reducer {

		@Override
		public void reduce(Text key, Iterator values,
				OutputCollector output, Reporter reduce)
				throws IOException {
			// TODO Auto-generated method stub
			String csv = "";
			while (values.hasNext()) {
				if (csv.length() > 0)
					csv += ",";
				csv += values.next().toString();
			}
			output.collect(key, new Text(csv));
		}

	}

	@Override
	public int run(String[] arg0) throws Exception {
		// TODO Auto-generated method stub
		Configuration cOnf= getConf();
		JobConf job = new JobConf(conf, MyJob.class);

		// 输入输出路径
		Path in = new Path(arg0[0]);
		Path out = new Path(arg0[1]);

		FileInputFormat.setInputPaths(job, in);
		FileOutputFormat.setOutputPath(job, out);

		// 设置job的名字
		job.setJobName("MyJob");
		job.setMapperClass(MapClass.class);
		job.setReducerClass(Reduce.class);

		//设置K1，V1均为Text类型
		job.setInputFormat(KeyValueTextInputFormat.class);
		//设置输出到文本中的类型
		job.setOutputFormat(TextOutputFormat.class);
		//指定K2类型
		job.setOutputKeyClass(Text.class);
		//指定V2类型
		job.setOutputValueClass(Text.class);
		//对每一行以逗号分割
		job.set("key.value.separator.in.input.line", ",");

		JobClient.runJob(job);
		return 0;
	}

	public static void main(String[] args) throws Exception {
		// 定义本地输入文件路径
		String inputPath = "/home/znb/test/cite75_99.txt";
		// 定义输出的HDFS文件路径
		String outputPath = "hdfs://znb:9000/output/MyJob/";
		String[] args1 = { inputPath, outputPath };
		int res = ToolRunner.run(new Configuration(), new MyJob(), args1);
		System.exit(res);
	}
}