HBase 中加盐（Salting）之后的表如何读取：MapR...【黑马大数据培训】

package com.iteblog.data.hadoop; import org.apache.hadoop.hbase.Cell; import org.apache.hadoop.hbase.client.Result; import org.apache.hadoop.hbase.io.ImmutableBytesWritable; import org.apache.hadoop.hbase.mapreduce.TableMapper; import org.apache.hadoop.hbase.util.Bytes; import org.apache.hadoop.io.Text; import java.io.IOException; import java.util.List; import java.util.StringJoiner; public class HBaseMapper extends TableMapper<Text, Text> { @Override protected void map(ImmutableBytesWritable key, Result value, Context context) throws IOException, InterruptedException { String rowKey = Bytes.toString(value.getRow()); List<Cell> cells = value.listCells(); StringJoiner stringJoiner = new StringJoiner("\n"); for (Cell cell : cells) { String family = Bytes.toString(cell.getFamilyArray(), cell.getFamilyOffset(), cell.getFamilyLength()); String qualifier = Bytes.toString(cell.getQualifierArray(), cell.getQualifierOffset(), cell.getQualifierLength()); String v = Bytes.toString(cell.getValueArray(), cell.getValueOffset(), cell.getValueLength()); stringJoiner.add("column=" + family + ":" + qualifier + ", timestamp=" + cell.getTimestamp() + ", value=" + v) ; } context.write(new Text(rowKey), new Text(stringJoiner.toString())); } }

package com.iteblog.data.hadoop; import com.iteblog.data.spark.SaltRangeTableInputFormat; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.Path; import org.apache.hadoop.hbase.HBaseConfiguration; import org.apache.hadoop.hbase.client.Scan; import org.apache.hadoop.hbase.mapreduce.TableInputFormat; import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Job; import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; import org.apache.hadoop.mapreduce.lib.output.LazyOutputFormat; import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat; import java.io.IOException; public class Hadoop { public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException { Configuration conf = HBaseConfiguration.create(); conf.set("hbase.zookeeper.quorum", "https://www.iteblog.com:2181"); conf.set(TableInputFormat.SCAN_ROW_START, "1000"); conf.set(TableInputFormat.SCAN_ROW_STOP, "1001"); Job job = Job.getInstance(conf); job.setJobName("iteblog_HBase"); job.setJarByClass(Hadoop.class); job.setNumReduceTasks(1); TableMapReduceUtil.initTableMapperJob("iteblog", new Scan(), HBaseMapper.class, Text.class, Text.class, job, true, SaltRangeTableInputFormat.class); FileOutputFormat.setOutputPath(job, new Path("hdfs://www.iteblog.com:8020/result/")); LazyOutputFormat.setOutputFormatClass(job, TextOutputFormat.class); int result = job.waitForCompletion(true) ? 0 : 1; } }

hadoop jar ~/hbase-1.0-SNAPSHOT.jar com.iteblog.data.hadoop.Hadoop

[root@master hadoop-2.7.7]# hadoop fs -ls /result Found 2 items -rw-r--r-- 1 iteblog supergroup 0 2019-02-02 22:54 /result/_SUCCESS -rw-r--r-- 1 iteblog supergroup 14442 2019-02-02 22:54 /result/part-r-00000 A-1000-1550572395399 column=f:age, timestamp=1549091990253, value=54 column=f:uuid, timestamp=1549091990253, value=e9b10a9f-1218-43fd-bd01 A-1000-1550572413799 column=f:age, timestamp=1549092008575, value=4 column=f:uuid, timestamp=1549092008575, value=181aa91e-5f1d-454c-959c A-1000-1550572414761 column=f:age, timestamp=1549092009531, value=33 column=f:uuid, timestamp=1549092009531, value=19aad8d3-621a-473c-8f9f B-1000-1550572388491 column=f:age, timestamp=1549091983276, value=1 column=f:uuid, timestamp=1549091983276, value=cf720efe-2ad2-48d6-81b8 B-1000-1550572392922 column=f:age, timestamp=1549091987701, value=7 column=f:uuid, timestamp=1549091987701, value=8a047118-e130-48cb-adfe B-1000-1550572424681 column=f:age, timestamp=1549092019451, value=57 column=f:uuid, timestamp=1549092019451, value=4217ab00-7cb9-4a81-bf29 C-1000-1550572390493 column=f:age, timestamp=1549091985284, value=89 column=f:uuid, timestamp=1549091985284, value=414d7df1-1925-4aaa-8298