1、从hbase中取数据，再把计算结果插入hbase中

package com.yeliang;
import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.Put;
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.mapred.TableInputFormat;
import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
import org.apache.hadoop.hbase.mapreduce.TableMapper;
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.IntWritable;
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.mapreduce.lib.input.TextInputFormat;

/**
 * 从hbase里取数据，分析完成后插入到hbase里
 * @author liang.ye
 *
 */
public class FamilyHBase {

    public static class Map extends TableMapper<Text, IntWritable>{

		@Override
		protected void map(ImmutableBytesWritable key, Result value, Context context)
				throws IOException, InterruptedException {
			for (Cell cell : value.rawCells())  
            {  
				if(new String(CellUtil.cloneQualifier(cell)).equals("GroupID")){
					context.write(new Text(new String(CellUtil.cloneValue(cell))), new IntWritable(1));
				}
            }  
		}
    }

    public static class Reduce extends
            TableReducer<Text, IntWritable, NullWritable> {
        public void reduce(Text key, Iterable<IntWritable> values,
                Context context) throws IOException, InterruptedException {
            int sum = 0;
            for (IntWritable i : values) {
                sum += i.get();
            }
            byte[] keyBytes = Bytes.toBytes(key.toString());
            if(keyBytes.length>0){
            	Put put = new Put(keyBytes);
                // Put实例化，每一个词存一行
                put.add(Bytes.toBytes("content"), Bytes.toBytes("count"),
                        Bytes.toBytes(String.valueOf(sum)));
                // 列族为content，列为count，列值为数目
                context.write(NullWritable.get(), put);
            }
        }
    }

    public static void createHBaseTable(String tableName) throws IOException {
        HTableDescriptor htd = new HTableDescriptor(tableName);
        HColumnDescriptor col = new HColumnDescriptor("content");
        htd.addFamily(col);
        Configuration conf = HBaseConfiguration.create();
        conf.set("hbase.zookeeper.quorum","192.168.56.101,192.168.56.102,192.168.56.103");
        HBaseAdmin admin = new HBaseAdmin(conf);
        if (admin.tableExists(tableName)) {
            System.out.println("table exists, trying to recreate table......");
            admin.disableTable(tableName);
            admin.deleteTable(tableName);
        }
        System.out.println("create new table:" + tableName);
        admin.createTable(htd);
    }

    public static void main(String[] args) throws IOException,
            InterruptedException, ClassNotFoundException {
        String tableName = "family_sum_by_groupid";
        Configuration conf = HBaseConfiguration.create();
        //conf.set("hbase.zookeeper.quorum","192.168.56.101,192.168.56.102,192.168.56.103");
        createHBaseTable(tableName);
        Job job = new Job(conf, "family_sum_by_groupid ");
        job.setJarByClass(FamilyHBase.class);
        Scan scan = new Scan();
        scan.addFamily("cf".getBytes());
        TableMapReduceUtil.initTableMapperJob("family3", scan, Map.class, Text.class, IntWritable.class, job);
        TableMapReduceUtil.initTableReducerJob(tableName, Reduce.class, job);
        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }
}

　　2、从hdfs中取数据，把计算的结果插入到hdfs中

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.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.Put;
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.IntWritable;
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.mapreduce.lib.input.TextInputFormat;

/**
 * 从hdfs中取数分析，然后插入到hbase里
 * @author liang.ye
 *
 */
public class WordCountHBase {

    public static class Map extends
            Mapper<LongWritable, Text, Text, IntWritable> {
        private IntWritable i = new IntWritable(1);

        public void map(LongWritable key, Text value, Context context)
                throws IOException, InterruptedException {
            String s[] = value.toString().trim().split(" ");
            // 将输入的每行以空格分开
            for (String m : s) {
                context.write(new Text(m), i);
            }
        }
    }

    public static class Reduce extends
            TableReducer<Text, IntWritable, NullWritable> {
        public void reduce(Text key, Iterable<IntWritable> values,
                Context context) throws IOException, InterruptedException {
            int sum = 0;
            for (IntWritable i : values) {
                sum += i.get();
            }
            byte[] keyBytes = Bytes.toBytes(key.toString());
            if(keyBytes.length>0){
            	Put put = new Put(keyBytes);
                // Put实例化，每一个词存一行
                put.add(Bytes.toBytes("content"), Bytes.toBytes("count"),
                        Bytes.toBytes(String.valueOf(sum)));
                // 列族为content，列为count，列值为数目
                context.write(NullWritable.get(), put);
            }
        }
    }

    public static void createHBaseTable(String tableName) throws IOException {
        HTableDescriptor htd = new HTableDescriptor(tableName);
        HColumnDescriptor col = new HColumnDescriptor("content");
        htd.addFamily(col);
        Configuration conf = HBaseConfiguration.create();
        conf.set("hbase.zookeeper.quorum","192.168.56.101,192.168.56.102,192.168.56.103");
        HBaseAdmin admin = new HBaseAdmin(conf);
        if (admin.tableExists(tableName)) {
            System.out.println("table exists, trying to recreate table......");
            admin.disableTable(tableName);
            admin.deleteTable(tableName);
        }
        System.out.println("create new table:" + tableName);
        admin.createTable(htd);
    }

    public static void main(String[] args) throws IOException,
            InterruptedException, ClassNotFoundException {
        String tableName = "WordCount2";
        Configuration conf = new Configuration();
        conf.set(TableOutputFormat.OUTPUT_TABLE, tableName);
        createHBaseTable(tableName);
        String input = args[0];
        Job job = new Job(conf, "WordCount table with " + input);
        job.setJarByClass(WordCountHBase.class);
        job.setNumReduceTasks(3);
        job.setMapperClass(Map.class);
        job.setReducerClass(Reduce.class);
        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(IntWritable.class);
        job.setInputFormatClass(TextInputFormat.class);
        job.setOutputFormatClass(TableOutputFormat.class);
        FileInputFormat.addInputPath(job, new Path(input));
        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }
}