Package io.datarouter.scanner

Class BaseLinkedScanner<T,R>

java.lang.Object

io.datarouter.scanner.BaseScanner<R>

io.datarouter.scanner.BaseLinkedScanner<T,R>

All Implemented Interfaces:

Scanner<R>, Closeable, AutoCloseable

Direct Known Subclasses:

AdvanceUntilScanner, AdvanceWhileScanner, BatchingScanner, ComparableScanner, ConcatenatingScanner, DeduplicatingScanner, DistinctScanner, EachScanner, FilteringScanner, LimitingScanner, MappingScanner, PrefetchingScanner, RetainingScanner, SamplingScanner, ShufflingScanner, SortingScanner, SplittingScanner, SteppingScanner

public abstract class BaseLinkedScanner<T,R>
extends BaseScanner<R>

Subclasses do not have to worry about closing the input scanner.

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	closed
protected Scanner<T>	input

Fields inherited from class io.datarouter.scanner.BaseScanner

current

Constructor Summary

Constructors

Constructor	Description
BaseLinkedScanner(Scanner<T> input)

Method Summary

Modifier and Type	Method	Description
boolean	advance()	Try to update current to the next item, if there is one.
protected abstract boolean	advanceInternal()
void	close()	Override to cleanup any resources.
protected void	closeInternal()	Extend to close internal resources before the input scanner is closed.

Methods inherited from class io.datarouter.scanner.BaseScanner

current

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.datarouter.scanner.Scanner

advanceUntil, advanceWhile, allMatch, anyMatch, append, append, append, apply, batch, collate, collate, collect, collect, concat, concatIter, count, deduplicate, deduplicateBy, distinct, distinctBy, each, exclude, findAny, findFirst, findLast, flush, forEach, groupBy, groupBy, groupBy, groupBy, hasAny, include, isEmpty, iterable, iterator, limit, link, list, listTo, map, max, min, noneMatch, parallel, prefetch, reduce, reduce, retain, sample, shuffle, skip, sorted, sorted, splitBy, stream, streamDoubles, streamInts, streamLongs, take, then, toArray, toMap, toMap, toMap, toMap, toMapSupplied, toMapSupplied, toMapSupplied, toMapSupplied

Field Details

input

protected final Scanner<T> input

closed

protected boolean closed

Constructor Details

BaseLinkedScanner

public BaseLinkedScanner(Scanner<T> input)

Method Details

advanceInternal

protected abstract boolean advanceInternal()

advance

public final boolean advance()

Description copied from interface: Scanner

Try to update current to the next item, if there is one.

Returns:

True if it advanced

closeInternal

protected void closeInternal()

Extend to close internal resources before the input scanner is closed.

close

public final void close()

Description copied from interface: Scanner

Override to cleanup any resources. The call should be propagated to all parent scanners. In the infrequent case of calling advance/current in an application, the Scanner should be explicitly closed. Because the included Scanner operations will close themselves when they fail to advance, it frequently a no-op for the application, unless closing the scanner before it stops advancing.