Hbase数据导入Hdfs

hbase数据导入到hdfs，主要是通过TableMapper实现读取hbase表数据，写入hdfs目录，话不多说，直接上的代码（亲测可用）

package com.test.transform;

import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
import org.apache.hadoop.hbase.mapreduce.TableMapper;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

/**
* @ClassName: HbaseToHdfs
* @Description: hbase全表数据导入hdfs
* @author gy
* @date 2018年7月13日下午3:59:11
*
*/
public class HbaseToHdfs {
public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {

       String tablename = "mr:test";// 表名字
       String outputpath = "hdfs://IP地址/output";//输出路径
       Configuration conf = HBaseConfiguration.create();
       conf.set("hbase.zookeeper.quorum", "zookeeper IP地址");
       conf.set("hbase.zookeeper.property.clientPort", "端口号");
       conf.set("zookeeper.znode.parent", "/hbase");

       Job job = Job.getInstance(conf, "HbaseToHdfs");
       job.setJarByClass(HbaseToHdfs.class);
       Scan scan = new Scan();
       TableMapReduceUtil.initTableMapperJob(tablename, scan, doMapper.class, Text.class, Text.class, job);
       job.setReducerClass(WordCountHbaseReaderReduce.class);
       FileOutputFormat.setOutputPath(job, new Path(outputpath));
       System.exit(job.waitForCompletion(true) ? 0 : 1);
   }

   public static class doMapper extends TableMapper<Text, Text> {
       protected void map(ImmutableBytesWritable key, Result value, Context context)
               throws IOException, InterruptedException {
           // 获取对应的字段
           String TOWNSHIP = new String(value.getValue("ColumnFamily1".getBytes(), "TOWNSHIP".getBytes()), "utf-8");

           context.write(new Text(""), new Text(TOWNSHIP));
       }
   }

   public static class WordCountHbaseReaderReduce extends Reducer<Text, Text, Text, Text> {
       private Text result = new Text();

       protected void reduce(Text key, Iterable<Text> values, Context context)
               throws IOException, InterruptedException {
           for (Text val : values) {
               result.set(val);
               context.write(key, result);
           }
       }
   }
}

猜你喜欢