CODEWITHSUNDEEP
javahbase
markiz
markiz

Reputation: 2184

Hbase extracting value and timestamp from a cell

In hbase I have number of columns: name, city,...
Not all columns have values ( some rows can have only 'name' for example)

I want to extract all columns in a row + timestamp of column (in specific order), in case value is null I want to return empty string.

The problem that I facing, I must access column in Result by 'family' and 'qualifier' (I can't access by index of result.listCells().get(i) because null values are skipped)

scan.addColumn(Bytes.toBytes("personal data"), Bytes.toBytes("name"));
scan.addColumn(Bytes.toBytes("personal data"), Bytes.toBytes("city"));

ResultScanner scanner = table.getScanner(scan);

for (Result result = scanner.next(); result != null; result = scanner.next()){

    byte [] valCity = result.getValue("personal data", "city"); //can't get timestamp using this
  //check if valCity null write ("") else write the value
  //next column... 
}

Upvotes: 5

Views: 4850

Answers (1)

Alexander Kuznetsov
Alexander Kuznetsov

Reputation: 3112

You can try to use a CellScanner for this. See example below: 

    CellScanner cellScanner = result.cellScanner();
    while (cellScanner.advance()) {
        Cell cell = cellScanner.current();
        byte[] columnName = Bytes.copy(cell.getQualifierArray(),
                cell.getQualifierOffset(),
                cell.getQualifierLength());
        byte[] familyName = Bytes.copy(cell.getFamilyArray(),
                cell.getFamilyOffset(),
                cell.getFamilyLength());
        long timestamp = cell.getTimestamp();
        .....
    }

Upvotes: 2

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