mapreduce HDFS 写入hbase 表中

本文介绍如何使用MapReduce从HDFS读取数据,经过处理后将结果存储到HBase数据库中,详细阐述了MapReduce任务的配置和HBase的写入操作。

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import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
import org.apache.hadoop.hbase.mapreduce.TableOutputFormat;
import org.apache.hadoop.hbase.mapreduce.TableReducer;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.util.GenericOptionsParser;

import java.io.IOException;

public class HDFS2HBASE {

    private static class HdfsToHbaseMapper extends Mapper<LongWritable, Text, Text, Put> {
        private String family = "cf";
        private String[] qualifier = {"id","gender","age"};
        //private String[] qualifier = {"id","gender","age","name"};
        private String hdfs_split = ",";
        private String hbase_split = "|";
        @Override
        protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
            //拿到一行文件按分割符分割
            String[] fileds = value.toString().split(this.hdfs_split);
            //读取配置文件
            Configuration conf = context.getConfiguration();
            String row_key = getKey(conf.get("hdfs_index"), fileds);
//            String rowvalue = getValue(fileds);
            if(fileds.length==qualifier.length){
                Put put = new Put(Bytes.toBytes(row_key));
                for(int i=0;i<fileds.length;i++){
                    String qul=qualifier[i];
                    String val=fileds[i];
                    put.add(family.getBytes(), qul.getBytes(), val.getBytes());
                }
                context.write(new Text(row_key), put);
            }else {
                System.out.println(" ERROR: value length must equale qualifier length ");
                //System.err.println(" ERROR: value length must equale qualifier length ");
            }

        }

        //for 得到key值
        public String getKey(String index, String[] fileds) {
            String[] indexs = index.split(this.hdfs_split);
            StringBuffer res_key = new StringBuffer();
            //res_key.append(fileds[Integer.parseInt(indexs[0])]);
            for (int i = 0; i < indexs.length; i++) {
                res_key.append(fileds[java.lang.Integer.parseInt(indexs[i])] + this.hbase_split);
            }
            //return res_key.toString();
            return res_key.deleteCharAt(res_key.length() - 1).toString();
        }

        //for 得到value值
        public String getValue(String[] flies) {
            StringBuffer res_value = new StringBuffer();
            //res_value.append(flies[1]);
                for (int i = 1; i < flies.length; i++) {
                    res_value.append(flies[i] + ",");
                }


            //res_value.delete(res_value.length()-1,res_value.length());
            //res_value.deleteCharAt(res_value.length()-1);
            return res_value.deleteCharAt(res_value.length() - 1).toString();
        }
    }

    public static class HdfsToHbaseReducer extends TableReducer<Text, Put, NullWritable> {

        @Override
        protected void reduce(Text key, Iterable<Put> values, Context context) throws IOException, InterruptedException {
            //读出来的每一行数据写入到 fruit_hdfs 表中
            for (Put put : values) {
                context.write(NullWritable.get(), put);
            }
        }
    }

    public static Job createSubmittableJob(Configuration conf, String[] args) throws IOException {
        String hbase_table_name = args[0];
        String hbase_inPath = args[1];
        String hdfs_index = args[2];
        conf.set("hbase_table_name", hbase_table_name);
        conf.set("hbase_inPath", hbase_inPath);
        conf.set("hdfs_index", hdfs_index);
        Job job = Job.getInstance(conf, HDFS2HBASE.class.getSimpleName());
        TableMapReduceUtil.initTableReducerJob(
                hbase_table_name,        // output table
                HdfsToHbaseReducer.class,    // reducer class
                job);
        job.setNumReduceTasks(0);
        job.setReducerClass(HdfsToHbaseReducer.class);
        job.setJarByClass(HDFS2HBASE.class);
        job.setMapperClass(HdfsToHbaseMapper.class);
        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(Put.class);
        FileInputFormat.addInputPath(job, new Path(args[1]));
        job.setOutputFormatClass(TableOutputFormat.class);
        return job;
    }

    public static void main(String[] args) throws InterruptedException, IOException, ClassNotFoundException {
        Configuration conf = HBaseConfiguration.create();
        //设置压缩格式
        conf.set("mapreduce.output.fileoutputformat.compress", "false");
        //设置内存
        conf.set("mapreduce.map.memory.mb", "2048");
        //
        //conf.set("hbase.zookeeper.property.clientPort", "11001");//TODO zk client端口   9501
        //conf.set("hbase.zookeeper.quorum", "xxxxxxxxxxxxxxx");//TODO zk 服务器  
        //conf.set("hbase.zookeeper.quorum", "xxxxxxxxxxxxxxxxxxxx");

        //生产环境
        conf.set("hbase.zookeeper.property.clientPort", "9501");
        conf.set("hbase.zookeeper.quorum", "xxxxxxxxxxxxxxxxxxxxxx");

        String[] otherArgs = new GenericOptionsParser(conf, args)
                .getRemainingArgs();
        if (otherArgs.length != 3) {
            System.out.println("Wrong number of arguments: " + otherArgs.length);
            System.exit(-1);
        }
        Job job = createSubmittableJob(conf, otherArgs);
        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }
}
结果:

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