Multiple Approaches for Creating HBase Result Object for Testing

During our testing of various Hbase based Mappers, we have to create Result object for passing it to mappers.

The easy approach is to create a list of KeyValue as below.

[code language="java"]
List kvs = new ArrayList();
kvs.add(new KeyValue(key.get(), COL_FAMILY, FIRST_NAME_COL_QUALIFIER, Bytes.toBytes(csvCells[1])));
kvs.add(new KeyValue(key.get(), COL_FAMILY, FIRST_NAME_COL_QUALIFIER, Bytes.toBytes(csvCells[2])));
kvs.add(new KeyValue(key.get(), COL_FAMILY, FIRST_NAME_COL_QUALIFIER, Bytes.toBytes(csvCells[3])));
Result result = new Result(kvs);
[/code]

The approach should work good but it does not when we do getValue from the Result Object.

The data in Result object should be sorted but in above case the input is unsorted.

Two approaches to sort it:

1. Using KeyValue.COMPARATOR.

[code language="java"]
protected Result keyValueToResult(List<KeyValue> kvs) {
KeyValue[] kvsArray = kvs.toArray(new KeyValue[0]);
Arrays.sort(kvsArray, KeyValue.COMPARATOR);
List<KeyValue> kvsSorted = Arrays.asList(kvsArray);
return new Result(kvsSorted);
}
[/code]

2. Using MockHTable.

[code language="java"]
public Result getResultV2(String csvRecord)
throws Exception {
MockHTable mockHTable = MockHTable.create();

final byte[] COL_FAMILY = "CF".getBytes();
final byte[] FIRST_NAME_COL_QUALIFIER = "fn".getBytes();
final byte[] MIDDLE_NAME_COL_QUALIFIER = "mi".getBytes();
final byte[] LAST_NAME_COL_QUALIFIER = "ln".getBytes();

CSVReader csvReader = new CSVReader(new StringReader(csvRecord), ',');
String[] csvCells = csvReader.readNext();

ImmutableBytesWritable key = getKey(csvRecord);

Put put = new Put(key.get());
put.add(COL_FAMILY, FIRST_NAME_COL_QUALIFIER, Bytes.toBytes(csvCells[1]));
put.add(COL_FAMILY, FIRST_NAME_COL_QUALIFIER, Bytes.toBytes(csvCells[2]));
put.add(COL_FAMILY, FIRST_NAME_COL_QUALIFIER, Bytes.toBytes(csvCells[3]));
mockHTable.put(put);

return mockHTable.get(new Get(key.get()));

}
[/code]

The usage of MockTable is good but as well complex also.

References:

1. Apache HBase


2. HBase QuickStart


3. HBase Unit Testing


4. Hbase Testing