Shulou(Shulou.com)06/01 Report--

Import java.io.IOException;import java.util.HashMap;import java.util.Map;import java.util.Set;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.hbase.HBaseConfiguration;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.MultiTableOutputFormat;import org.apache.hadoop.hbase.mapreduce.TableInputFormat Import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;import org.apache.hadoop.hbase.mapreduce.TableMapper;import org.apache.hadoop.hbase.util.Bytes;import org.apache.hadoop.mapreduce.Job;import org.apache.hadoop.util.GenericOptionsParser;public class IndexBuilder {private class MyMapper extends TableMapper {private Map indexes = new HashMap (); private String columnFamily @ Override protected void map (ImmutableBytesWritable key, Result value, Context context) throws IOException, InterruptedException {Set keys = indexes.keySet (); for (byte [] k: keys) {ImmutableBytesWritable indexTableName = indexes.get (k); byte [] val = value.getValue (Bytes.toBytes (columnFamily), k); Put put = new Put (val) / / the rowkey of the index table is the value put.add of the original table (Bytes.toBytes ("F1"), Bytes.toBytes ("id"), key.get (); / / the content of the index table is the rowkey context.write (indexTableName, put) of the original table. } @ Override protected void setup (Context context) throws IOException, InterruptedException {Configuration conf = context.getConfiguration (); String tableName = conf.get ("tableName"); columnFamily = conf.get ("columnFamily"); String [] qualifiers = conf.getStrings ("qualifiers") / / key of indexes is the column name, and value is the index table name for (String Q: qualifiers) {indexes.put (Bytes.toBytes (Q), new ImmutableBytesWritable (Bytes.toBytes (tableName + "-" + Q) } public static void main (String [] args) throws IOException, ClassNotFoundException, InterruptedException {Configuration conf = HBaseConfiguration.create (); String [] otherargs = new GenericOptionsParser (conf, args) .getRemainingArgs () / / remove useless command line arguments / / input parameters: table name, column family name, column name if (otherargs.length < 3) {System.exit (- 1);} String tableName = otherargs [0]; String columnFamily = otherargs [1]; conf.set ("tableName", tableName); conf.set ("columnFamily", columnFamily) String [] qualifiers = new String [otherargs.length-2]; for (int I = 0; I < qualifiers.length; I +) {qualifiers [I] = otherargs [I + 2];} conf.setStrings ("qualifiers", qualifiers); Job job = new Job (conf, tableName); job.setJarByClass (IndexBuilder.class); job.setMapperClass (MyMapper.class); job.setNumReduceTasks (0) Job.setInputFormatClass (TableInputFormat.class); / / you can output multiple tables job.setOutputFormatClass (MultiTableOutputFormat.class); Scan scan = new Scan (); scan.setCaching (1000); TableMapReduceUtil.initTableMapperJob (tableName, scan, MyMapper.class, ImmutableBytesWritable.class, Put.class, job); job.waitForCompletion (true);}}

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