org.apache.hadoop.hbase.client

Interface ResultScanner

All Superinterfaces:

AutoCloseable, Closeable, Iterable<Result>

All Known Implementing Classes:

AbstractClientScanner, ClientAsyncPrefetchScanner, ClientScanner, ClientSideRegionScanner, ClientSimpleScanner, ReversedClientScanner, TableSnapshotScanner

@InterfaceAudience.Public
public interface ResultScanner
extends Closeable, Iterable<Result>

Interface for client-side scanning. Go to Table to obtain instances.

Method Summary

Modifier and Type	Method and Description
void	close() Closes the scanner and releases any resources it has allocated
ScanMetrics	getScanMetrics()
default Iterator<Result>	iterator()
Result	next() Grab the next row's worth of values.
default Result[]	next(int nbRows) Get nbRows rows.
boolean	renewLease() Allow the client to renew the scanner's lease on the server.

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Method Detail

iterator

default Iterator<Result> iterator()

Specified by:

iterator in interface Iterable<Result>

next

Result next()
     throws IOException

Grab the next row's worth of values. The scanner will return a Result.

Returns:

Result object if there is another row, null if the scanner is exhausted.

Throws:

IOException - e

next

default Result[] next(int nbRows)
               throws IOException

Get nbRows rows. How many RPCs are made is determined by the Scan.setCaching(int) setting (or hbase.client.scanner.caching in hbase-site.xml).

Parameters:

nbRows - number of rows to return

Returns:

Between zero and nbRows rowResults. Scan is done if returned array is of zero-length (We never return null).

Throws:

IOException

close

void close()

Closes the scanner and releases any resources it has allocated

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

renewLease

boolean renewLease()

Allow the client to renew the scanner's lease on the server.

Returns:

true if the lease was successfully renewed, false otherwise.

getScanMetrics

ScanMetrics getScanMetrics()

Returns:

the scan metrics, or null if we do not enable metrics.