IncrementSingleExample.java

package client;

// cc IncrementSingleExample Example using the single counter increment methods
import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.util.Bytes;

import util.HBaseHelper;

public class IncrementSingleExample {

  public static void main(String[] args) throws IOException {
    Configuration conf = HBaseConfiguration.create();

    HBaseHelper helper = HBaseHelper.getHelper(conf);
    helper.dropTable("testtable");
    helper.createTable("testtable", "daily");
    Connection connection = ConnectionFactory.createConnection(conf);
    Table table = connection.getTable(TableName.valueOf("testtable"));
    // vv IncrementSingleExample
    long cnt1 = table.incrementColumnValue(Bytes.toBytes("20110101"), // co IncrementSingleExample-1-Incr1 Increase counter by one.
      Bytes.toBytes("daily"), Bytes.toBytes("hits"), 1);
    long cnt2 = table.incrementColumnValue(Bytes.toBytes("20110101"), // co IncrementSingleExample-2-Incr2 Increase counter by one a second time.
      Bytes.toBytes("daily"), Bytes.toBytes("hits"), 1);

    long current = table.incrementColumnValue(Bytes.toBytes("20110101"), // co IncrementSingleExample-3-GetCurrent Get current value of the counter without increasing it.
      Bytes.toBytes("daily"), Bytes.toBytes("hits"), 0);

    long cnt3 = table.incrementColumnValue(Bytes.toBytes("20110101"), // co IncrementSingleExample-4-Decr1 Decrease counter by one.
      Bytes.toBytes("daily"), Bytes.toBytes("hits"), -1);
    // ^^ IncrementSingleExample
    System.out.println("cnt1: " + cnt1 + ", cnt2: " + cnt2 +
      ", current: " + current + ", cnt3: " + cnt3);
  }
}