Hbase索引的建立实现代码

Hbase索引主要是用于提高Hbase中表数据的访问速度，有效的避免全表扫描。
简单的讲：将经常被查询的列作为行健，行健作为列键重新构造一张表，即可实现根据列值快速地定位相关数据所在的行，这就是索引。
下面是图片展示：

我自己写了实现代码不过和这图还是有不同，我定义的列是name,sex,tel，这些都不是重点啦。下面给大家讲讲具体的过程：
1，在tableMap过程：
我们拿到名字，和行健。
2，在tableReduce过程：
将拿到的名字做行健，行健做列，插入到Hbase中就可以哒。
代码展示：
建立母表：
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.util.Bytes;

public class CreateHbaseTable {    public static void main(String[] args) throws IOException {        Admin admin = null;        Connection con = null;            Configuration conf = HBaseConfiguration.create();// 获取hbase配置文件            conf.set("hbase.zookeeper.quorum", "192.168.61.128");            con = ConnectionFactory.createConnection(conf);            admin=con.getAdmin();//获得管理员            TableName tn=TableName.valueOf("workerinfo");            HTableDescriptor htd=new HTableDescriptor(tn);//创建表结构            HColumnDescriptor hcd=new HColumnDescriptor("info");            htd.addFamily(hcd);            admin.createTable(htd);//创建表            //向表中添加数据            Table table=con.getTable(tn);            for(int i=0;i<5;i++){                Put put=new Put((i+"").getBytes());                put.addColumn(Bytes.toBytes("info"), Bytes.toBytes("name"), Bytes.toBytes("zhangsan"+i))                .addColumn(Bytes.toBytes("info"), Bytes.toBytes("sex"), Bytes.toBytes("man"))                .addColumn(Bytes.toBytes("info"), Bytes.toBytes("tel"), Bytes.toBytes("0000"+i));                table.put(put);            }    }}

建立索引：

import java.io.IOException;import java.util.List;import org.apache.hadoop.conf.Configuration;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.TableName;import org.apache.hadoop.hbase.client.Admin;import org.apache.hadoop.hbase.client.Connection;import org.apache.hadoop.hbase.client.ConnectionFactory;import org.apache.hadoop.hbase.client.Mutation;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.mapreduce.TableMapReduceUtil;import org.apache.hadoop.hbase.mapreduce.TableMapper;import org.apache.hadoop.hbase.mapreduce.TableReducer;import org.apache.hadoop.hbase.util.Bytes;import org.apache.hadoop.mapreduce.Job;import org.apache.hadoop.mapreduce.Mapper;import org.apache.hadoop.mapreduce.Reducer;public class CreateHbaseIndex2 {    public static void main(String[] args) throws Exception {        Configuration conf = new Configuration();        conf = HBaseConfiguration.create(conf);        conf.set("hbase.zookeeper.quorum", "192.168.61.128");        Job job = Job.getInstance(conf, "HbaseIndex");        job.setJarByClass(CreateHbaseIndex2.class);        Scan scan=new Scan();        scan.addColumn(Bytes.toBytes("info"), Bytes.toBytes("name"));        TableMapReduceUtil.initTableMapperJob("workerinfo", scan, HbaseIndexMap.class,                 ImmutableBytesWritable.class, ImmutableBytesWritable.class,job);        TableMapReduceUtil.initTableReducerJob("HbaseIndex", HbaseIndexReduce.class, job);        checkTable(conf);        System.exit(job.waitForCompletion(true) ? 0 : 1);    }    private static class HbaseIndexMap extends TableMapper<ImmutableBytesWritable, ImmutableBytesWritable>{        @Override        protected void map(ImmutableBytesWritable key, Result value,                Mapper<ImmutableBytesWritable, Result, ImmutableBytesWritable, ImmutableBytesWritable>.Context context)                        throws IOException, InterruptedException {            List<Cell>  cs=value.listCells();            for(Cell cell:cs){                //name作为Key  行健作为值                context.write(new ImmutableBytesWritable(CellUtil.cloneValue(cell)), new ImmutableBytesWritable(CellUtil.cloneRow(cell)));            }        }    }    private static class HbaseIndexReduce extends TableReducer<ImmutableBytesWritable, ImmutableBytesWritable, ImmutableBytesWritable>{        @Override        protected void reduce(ImmutableBytesWritable key, Iterable<ImmutableBytesWritable> values,                Reducer<ImmutableBytesWritable, ImmutableBytesWritable, ImmutableBytesWritable, Mutation>.Context context)                        throws IOException, InterruptedException {            Put put=new Put(key.get());            for (ImmutableBytesWritable v : values) {                put.addColumn("oldrowkey".getBytes(),"index".getBytes(),v.get() );            }            context.write(key, put);        }    }    private static void checkTable(Configuration conf) throws Exception {        Connection con = ConnectionFactory.createConnection(conf);        Admin admin = con.getAdmin();        TableName tn = TableName.valueOf("HbaseIndex");        if (!admin.tableExists(tn)){            HTableDescriptor htd = new HTableDescriptor(tn);            HColumnDescriptor hcd = new HColumnDescriptor("oldrowkey".getBytes());            htd.addFamily(hcd);            admin.createTable(htd);            System.out.println("表不存在，新创建表成功....");        }    }}