把hdfs数据写入到hbase表

功能：把hdfs上的数据写入到hbase表。

hadoop的mapreduce输出要导入到hbase表，最好先输出HFile格式，再导入hbase,因为HFile是hbase的内部存储格式，所以导入效率很高，下面我们来看一下具体怎么做。

1、我们在hdfs上有一个文本文件：

　　

2、在hbase表里我们创建一个t1表

　　创建语句：create 't1','cf'

3、写MR作业

　　

 package cn.tendency.wenzhouhbase.hadoop;

 import java.io.IOException;
 import java.text.SimpleDateFormat;
 import java.util.Calendar;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.client.Mutation;
 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.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.Reducer;
 import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
 import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;

 public class Hadoop2Hbase {

     @SuppressWarnings("deprecation")
     public static void main(String[] args) throws Exception {
         Configuration conf = new Configuration();
         conf.set("hbase.zookeeper.quorum", "192.168.1.124,192.168.1.125,192.168.1.126");
         conf.set("hbase.zookeeper.property.clientPort", "2181");
         conf.set("hbase.master.port", "60000");
         conf.set("hbase.rootdir", "hdfs://192.168.1.122:9000/hbase");
         conf.set(TableOutputFormat.OUTPUT_TABLE, "t1");

         Job job = new Job(conf, Hadoop2Hbase.class.getSimpleName());
         TableMapReduceUtil.addDependencyJars(job);
         job.setJarByClass(Hadoop2Hbase.class);

         job.setMapperClass(HbaseMapper.class);
         job.setReducerClass(HbaseReducer.class);

         job.setMapOutputKeyClass(LongWritable.class);
         job.setMapOutputValueClass(Text.class);

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

         FileInputFormat.setInputPaths(job, "hdfs://192.168.1.123:9000/mytest/*");
         job.waitForCompletion(true);
     }

     static class HbaseMapper extends
             Mapper<LongWritable, Text, LongWritable, Text> {
         @Override
         protected void map(LongWritable key, Text value,
                 Mapper<LongWritable, Text, LongWritable, Text>.Context context)
                 throws IOException, InterruptedException {
             SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");
             String[] split = value.toString().split("\t");
             context.write(
                     key,
                     new Text(split[0]+sdf.format(Calendar.getInstance().getTime())
                             + "\t" + value.toString()));
         }
     }

     static class HbaseReducer extends
             TableReducer<LongWritable, Text, NullWritable> {
         @Override
         protected void reduce(
                 LongWritable key,
                 Iterable<Text> values,
                 Reducer<LongWritable, Text, NullWritable, Mutation>.Context context)
                 throws IOException, InterruptedException {
             for (Text text : values) {
                 String[] split = text.toString().split("\t");
                 Put put = new Put(split[0].getBytes());
                 put.addColumn("cf".getBytes(), "oneColumn".getBytes(), text
                         .toString().getBytes());
                 put.addColumn("cf".getBytes(), "id".getBytes(),
                         split[1].getBytes());
                 put.addColumn("cf".getBytes(), "name".getBytes(),
                         split[2].getBytes());
                 put.addColumn("cf".getBytes(), "age".getBytes(),
                         split[3].getBytes());
 //                put.addColumn("cf".getBytes(), "addr".getBytes(),
 //                        split[4].getBytes());
                 context.write(NullWritable.get(), put);
             }
         }
     }
 }