普通文本压缩成RcFile的通用类

package com.tool;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.GnuParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Options;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.serde2.columnar.BytesRefArrayWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

import com.xx.CommonMapper;
import com.xx.hadoop.rcfile.RCFileOutputFormat;

/**
 * CommonRcFileCompression.
 * 將普通的Text文件壓縮成RcFile格式的文件，節約存儲空間.
 * ${srcpath} 要壓縮的文件.
 * ${respath} 存放位置.
 * ${reducenum} reduce數.
 * ${sep} 分隔符.
 * ${colsum} 按sep分隔后一共幾列.
 * 
 * @author zhangk
 *
 */
public class CommonRcFileCompression extends Configured implements Tool, DataStatic {

    private static final String SRCPATH = "srcpath";
    private static final String RESPATH = "respath";
    private static final String SEP = "sep"; //分隔符
    private static final String COLSUM = "colsum"; //共幾列

    public static void main(String[] args) throws Exception {

        int exitcode = ToolRunner.run(new CommonRcFileCompression(), args);
        System.exit(exitcode);
    }

    @Override
    public int run(String[] args) throws Exception {
        int code = 0;

        Options options = new Options();
        options.addOption(DATE, true, DATE);
        options.addOption(SRCPATH, true, SRCPATH);
        options.addOption(RESPATH, true, RESPATH);
        options.addOption(SEP, true, "eg: 001");
        options.addOption(COLSUM, true, "eg:column sum");
        options.addOption(REDUCENUM, true, "eg:100");
        CommandLineParser parser = new GnuParser();
        HelpFormatter helper = new HelpFormatter();
        CommandLine line = null;
        try {
            line = parser.parse(options, args);
            if (!(line.hasOption(DATE) 
                    && line.hasOption(SRCPATH)
                    && line.hasOption(RESPATH)
                    && line.hasOption(SEP)
                    && line.hasOption(COLSUM)
                    && line.hasOption(REDUCENUM))
                    || "".equals(line.getOptionValue(DATE))
                    || "".equals(line.getOptionValue(SRCPATH))
                    || "".equals(line.getOptionValue(RESPATH))
                    || "".equals(line.getOptionValue(SEP))
                    || "".equals(line.getOptionValue(COLSUM))
                    || "".equals(line.getOptionValue(REDUCENUM))) {
                helper.printHelp("DisttibuteOrder", options);
                return 1;
            }
        } catch (Exception e) {
            helper.printHelp("DisttibuteOrder", options);
            e.printStackTrace();
        }

        String srcpath = line.getOptionValue(SRCPATH);
        String sep = line.getOptionValue(SEP);
        String colsum = line.getOptionValue(COLSUM);
        String respath = line.getOptionValue(RESPATH);
        String reducenum = line.getOptionValue(REDUCENUM);

        if (code == 0) {
            Job job = new Job();
            Configuration conf = job.getConfiguration();
            RCFileOutputFormat.setColumnNumber(conf, Tools.stringToInteger(colsum, 0));
            job.setJarByClass(CommonRcFileCompression.class);

            FileInputFormat.setInputPaths(job, new Path(srcpath));
            RCFileOutputFormat.setOutputPath(job, new Path(respath));

            job.setInputFormatClass(TextInputFormat.class);
            job.setOutputFormatClass(RCFileOutputFormat.class);

            job.setMapOutputKeyClass(LongWritable.class);
            job.setMapOutputValueClass(BytesRefArrayWritable.class);
            job.setNumReduceTasks(Integer.parseInt(reducenum));
            job.setMapperClass(CommonMapper.class);

            conf.set("sep", sep);
            conf.set("colsum", colsum);
            conf.setBoolean("mapred.output.compress", true);
            conf.set("mapred.output.compression.codec", "org.apache.hadoop.io.compress.GzipCodec");

            code = (job.waitForCompletion(true)) ? 0 : 1;
        }

        return code;
    }
}


package xxx.mapper;

import java.io.IOException;

import org.apache.hadoop.hive.serde2.columnar.BytesRefArrayWritable;
import org.apache.hadoop.hive.serde2.columnar.BytesRefWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;

import com.tool.DataStatic;
import com.tool.Tools;

/**
 * map讀入.
 * @author zhangk
 *
 */
public class CommonMapper extends Mapper implements DataStatic {

    @Override
    public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
        String sep = context.getConfiguration().get("sep");
        Integer colsum = Tools.stringToInteger(context.getConfiguration().get("colsum"), 0);
        String line = value.toString();
        if (!line.equals("")) {
            String[] lines = line.split(sep, NEGATIVE_ONE);
            if (lines.length >= colsum) {

                byte[][] record = makeByte(lines, colsum);

                BytesRefArrayWritable bytes = new BytesRefArrayWritable(record.length);

                for (int i = 0; i < record.length; i++) {
                    BytesRefWritable cu = new BytesRefWritable(record[i], 0, record[i].length);
                    bytes.set(i, cu);
                }
                context.write(key, bytes);
            }
        }
    }

    /**
     * 将行数据转换到byte数组中.
     * 
     * @param lines
     * @return
     */
    public static byte[][] makeByte(String[] lines, Integer colsum) {
        byte[][] record = new byte[colsum][colsum];
        for (int i = 0; i < colsum; i++) {
            record[i] = lines[i].getBytes();
        }
        return record;
    }
}

将工程打包命名：commonPress.jar
调用例子：
hadoop jar commonPress.jar -date=20120504 -srcpath=/xxx/xx/xx/2012/05/04/ -respath=/xxx/xx/xx/2012/05/04_1 -colsum=4 -sep=\\t -reducenum=40

参数：
日期
输入路径
输出路径
sep是分隔符
colsum是按照sep分隔后一共几列
reducenum是reduce的数量