hbase api - get data rows information by list of r

问题:

Is it possible to get hbase data records by list of row ids via hbase java API?

For example, I have a known list of hbase row ids:

mykey1:myhash1, mykey1:myhash2, mykey1:myhash3, mykey2:myhash5, ...

and I want to get with single call to hbase all relevant column cell informations. I'm pretty new to hbase and i don't know is this even supported by the API.

API pseudo code:

GetById(String tableName, List<byte[]> rowIds);

Something like that?

I can retrieve information from single row with Get(byte[] rowName), but when I have list of rowIds, I need to execute the get action several times, which cause establishing connection and closing it when completed each time.

Thanks

回答1:

Pass a list of Get operations to a batch call:

...
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.util.Bytes;
...
        HTable htable = null;
        try {
            htable = new HTable(conf, "mytable");
            List<Get> queryRowList = new ArrayList<Get>();
            queryRowList.add(new Get(Bytes.toBytes("mykey1:myhash1")));
            queryRowList.add(new Get(Bytes.toBytes("mykey1:myhash2")));
            queryRowList.add(new Get(Bytes.toBytes("mykey1:myhash3")));
            queryRowList.add(new Get(Bytes.toBytes("mykey2:myhash5")));

            Result[] results = htable.get(queryRowList);
            for (Result r : results) {
                //do something
            }
        }
        finally {
            if (htable != null) {
                htable.close();
            }
        }
...

回答2:

You can use MultiAction as a container for multiple get (or put, delete and combinations of them) that you can execute in batch.

That said, note that you can perform multiple get operations without closing/reopening the connection every time.