Help Center> CloudTable Service> Developer Guide> Developing HBase Applications> Sample Code Description> Using a Filter
View PDF

Using a Filter

Function Description

HBase Filter is used to filter data during Scan and Get. You can specify the filter criteria, such as filtering by RowKey, column name, or column value.

Sample Code

public void testSingleColumnValueFilter() {
  LOG.info("Entering testSingleColumnValueFilter.");
  Table table = null;
  ResultScanner rScanner = null;

  try {
    table = conn.getTable(tableName);
    Scan scan = new Scan();
    scan.addColumn(Bytes.toBytes("info"), Bytes.toBytes("name"));
    // Set the filter criteria.
    SingleColumnValueFilter filter = new SingleColumnValueFilter(
        Bytes.toBytes("info"), Bytes.toBytes("name"), CompareOp.EQUAL,
        Bytes.toBytes("I"));
    scan.setFilter(filter);
    // Submit a scan request.
    rScanner = table.getScanner(scan);
    // Print query results.
    for (Result r = rScanner.next(); r != null; r = rScanner.next()) {
      for (Cell cell : r.rawCells()) {
        LOG.info(Bytes.toString(CellUtil.cloneRow(cell)) + ":"
            + Bytes.toString(CellUtil.cloneFamily(cell)) + ","
            + Bytes.toString(CellUtil.cloneQualifier(cell)) + ","
            + Bytes.toString(CellUtil.cloneValue(cell)));
      }
    }
    LOG.info("Single column value filter successfully.");
  } catch (IOException e) {
    LOG.error("Single column value filter failed " ,e);
  } finally {
      if (rScanner != null) {
          // Close the scanner object.
          rScanner.close();
        }
    if (table != null) {
      try {
        // Close the HTable object.
        table.close();
      } catch (IOException e) {
        LOG.error("Close table failed " ,e);
      }
    }
  }
  LOG.info("Exiting testSingleColumnValueFilter.");
}
Parent topic: Sample Code Description