Reading Data Using Get

Function

Before reading data from a table, instantiate the Table instance of the table, and then create a Get object. You can also set parameters for the Get object, such as the column family name and column name. Query results are stored in the Result object that stores multiple Cells.

Example Code

The following code snippet belongs to the testGet method in the HBaseSample class of the com.huawei.bigdata.hbase.examples package.

public void testGet() {
    LOG.info("Entering testGet.");
    // Specify the column family name.
    byte[] familyName = Bytes.toBytes("info");
    // Specify the column name.
    byte[][] qualifier = { Bytes.toBytes("name"), Bytes.toBytes("address") };
    // Specify RowKey.
    byte[] rowKey = Bytes.toBytes("012005000201");
    Table table = null;
    try {
      // Create the Table instance.
      table = conn.getTable(tableName);
      // Instantiate a Get object.
      Get get = new Get(rowKey);
      // Set the column family name and column name.
      get.addColumn(familyName, qualifier[0]);
      get.addColumn(familyName, qualifier[1]);
      // Submit a get request.
      Result result = table.get(get);
      // Print query results.
      for (Cell cell : result.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("Get data successfully.");
    } catch (IOException e) {
      LOG.error("Get data failed " ,e);
    } finally {
      if (table != null) {
        try {
          // Close the HTable object.
          table.close();
        } catch (IOException e) {
          LOG.error("Close table failed " ,e);
        }
      }
    }
    LOG.info("Exiting testGet.");
  }