org.jdbi.v3.core.result

Interface ResultIterable<T>

Type Parameters:

T - iterable element type

All Superinterfaces:

Iterable<T>

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface ResultIterable<T>
extends Iterable<T>

An Iterable of values, usually mapped from a ResultSet. Generally, ResultIterables may only be traversed once.

Method Summary

Modifier and Type	Method and Description
default <R> R	collect(Collector<T,?,R> collector) Collect the results into a container specified by a collector.
default Optional<T>	findFirst()
default T	findOnly() Get the only row in the result set.
default void	forEach(Consumer<? super T> action)
ResultIterator<T>	iterator() Stream all the rows of the result set out with an Iterator.
default List<T>	list() Returns results in a List.
static <T> ResultIterable<T>	of(ResultIterator<T> iterator) Returns a ResultIterable backed by the given iterator.
static <T> ResultIterable<T>	of(Supplier<ResultSet> supplier, RowMapper<T> mapper, StatementContext ctx) Returns a ResultIterable backed by the given result set supplier, mapper, and context.
default <U> U	reduce(U identity, BiFunction<U,T,U> accumulator) Reduce the results.
default Stream<T>	stream() Returns the stream of results.
default <X extends Exception> void	useStream(StreamConsumer<T,X> consumer) Passes the stream of results to the consumer.
default <R,X extends Exception> R	withStream(StreamCallback<T,R,X> callback) Passes the stream of results to the callback.

Methods inherited from interface java.lang.Iterable

spliterator

Method Detail

collect

default <R> R collect(Collector<T,?,R> collector)

Collect the results into a container specified by a collector.

Type Parameters:

R - the generic type of the container

Parameters:

collector - the collector

Returns:

the container with the query result

findFirst

default Optional<T> findFirst()

Returns:

the first row in the result set, if present.

findOnly

default T findOnly()

Get the only row in the result set.

Returns:

the object mapped from the singular row in the results

Throws:

IllegalStateException - if zero or multiple rows are returned

forEach

default void forEach(Consumer<? super T> action)

Specified by:

forEach in interface Iterable<T>

iterator

ResultIterator<T> iterator()

Stream all the rows of the result set out with an Iterator. The Iterator must be closed to release database resources.

Specified by:

iterator in interface Iterable<T>

Returns:

the results as a streaming Iterator

list

default List<T> list()

Returns results in a List.

Returns:

results in a List.

of

static <T> ResultIterable<T> of(ResultIterator<T> iterator)

Returns a ResultIterable backed by the given iterator.

Type Parameters:

T - iterator element type

Parameters:

iterator - the result iterator

Returns:

a ResultIterable

of

static <T> ResultIterable<T> of(Supplier<ResultSet> supplier,
                                RowMapper<T> mapper,
                                StatementContext ctx)

Returns a ResultIterable backed by the given result set supplier, mapper, and context.

Type Parameters:

T - the mapped type

Parameters:

supplier - result set supplier

mapper - row mapper

ctx - statement context

Returns:

the result iterable

reduce

default <U> U reduce(U identity,
                     BiFunction<U,T,U> accumulator)

Reduce the results. Using a BiFunction<U, T, U>, repeatedly combine query results until only a single value remains.

Type Parameters:

U - the accumulator type

Parameters:

identity - the U to combine with the first result

accumulator - the function to apply repeatedly

Returns:

the final U

stream

default Stream<T> stream()

Returns the stream of results.

Note: the returned stream owns database resources, and must be closed via a call to BaseStream.close(), or by using the stream in a try-with-resources block:

 try (Stream<T> stream = query.stream()) {
   // do stuff with stream
 }
 

Returns:

the stream of results.

See Also:

useStream(StreamConsumer), withStream(StreamCallback)

useStream

default <X extends Exception> void useStream(StreamConsumer<T,X> consumer)
                                      throws X extends Exception

Passes the stream of results to the consumer. Database resources owned by the query are released before this method returns.

Type Parameters:

X - the exception type thrown by the callback, if any

Parameters:

consumer - a consumer which receives the stream of results.

Throws:

X - any exception thrown by the callback

X extends Exception

withStream

default <R,X extends Exception> R withStream(StreamCallback<T,R,X> callback)
                                      throws X extends Exception

Passes the stream of results to the callback. Database resources owned by the query are released before this method returns.

Type Parameters:

R - the type returned by the callback

X - the exception type thrown by the callback, if any

Parameters:

callback - a callback which receives the stream of results, and returns some result.

Returns:

the value returned by the callback.

Throws:

X - any exception thrown by the callback

X extends Exception