code: private ColumnDef getColumnDefByName(CfDef columnFamily, ByteBuffer columnName)
      {
          for (ColumnDef columnDef : columnFamily.getColumn_metadata())
          {
              byte[] currName = columnDef.getName();
  
              if (ByteBufferUtil.compare(currName, columnName) == 0)
              {
                  return columnDef;
              }
          }
  
          return null;
      }
docs: Get specific ColumnDef in column family meta data by column name
  @param columnFamily - CfDef record
  @param columnName   - column name represented as byte[]
  @return ColumnDef   - found column definition