使用Get读取数据

功能简介

要从表中读取一条数据，首先需要实例化该表对应的Table实例，然后创建一个Get对象。也可以为Get对象设定参数值，如列族的名称和列的名称。查询到的行数据存储在Result对象中，Result中可以存储多个Cell。

代码样例

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.");
}