Module org.cojen.tupl

Package org.cojen.tupl

Interface Scanner<R>

All Superinterfaces:

AutoCloseable, Closeable, Spliterator<R>

All Known Subinterfaces:

Updater<R>

public interface Scanner<R>
extends Spliterator<R>, Closeable

Support for scanning through all rows in a table. Any exception thrown when acting upon a scanner automatically closes it.

Scanner instances can only be safely used by one thread at a time, and they must be closed when no longer needed. Instances can be exchanged by threads, as long as a happens-before relationship is established. Without proper exclusion, multiple threads interacting with a Scanner instance may cause database corruption.

See Also:

• Table.newScanner
• Updater

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Spliterator

Spliterator.OfDouble, Spliterator.OfInt, Spliterator.OfLong, Spliterator.OfPrimitive<T extends Object,T_CONS extends Object,T_SPLITR extends Spliterator.OfPrimitive<T,T_CONS,T_SPLITR>>

Field Summary

Fields inherited from interface java.util.Spliterator

CONCURRENT, DISTINCT, IMMUTABLE, NONNULL, ORDERED, SIZED, SORTED, SUBSIZED

Method Summary

Modifier and Type	Method	Description
void	close()
default void	forEachRemaining(Consumer<? super R> action)
R	row()	Returns a reference to the current row, which is null if the scanner is closed.
R	step()	Step to the next row.
R	step(R row)	Step to the next row.
default boolean	tryAdvance(Consumer<? super R> action)
default Spliterator<R>	trySplit()

Methods inherited from interface java.util.Spliterator

characteristics, estimateSize, getComparator, getExactSizeIfKnown, hasCharacteristics

Method Details

row

R row()

Returns a reference to the current row, which is null if the scanner is closed.

step

R step()
throws IOException

Step to the next row.

Returns:

the next row or null if no more rows remain and scanner has been closed

Throws:

IOException

step

R step(R row)
throws IOException

Step to the next row.

Parameters:

row - use this for the next row instead of creating a new one

Returns:

the next row or null if no more rows remain and scanner has been closed

Throws:

NullPointerException - if the given row object is null

IOException

tryAdvance

default boolean tryAdvance(Consumer<? super R> action)

Specified by:

tryAdvance in interface Spliterator<R>

forEachRemaining

default void forEachRemaining(Consumer<? super R> action)

Specified by:

forEachRemaining in interface Spliterator<R>

trySplit

default Spliterator<R> trySplit()

Specified by:

trySplit in interface Spliterator<R>

close

void close()
    throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException