Convert Iterable to Stream using Java 8 JDK

Direct Conversion for Collection Types

If your Iterable is masquerading as a Collection, you can convert it directly using the stream() function:

Collection<T> collection = // your collection here
Stream<T> stream = collection.stream();
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Most Collection use stealthily efficient spliterators, potentially enhancing conversion speed.

Libraries: Guava and JOOQ’s Techniques

Guava Sneak Attack

Guava library (version 21.0 onwards) provides a ninja move for conversion:

import com.google.common.collect.Streams;

Stream<T> stream = Streams.stream(iterable);
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JOOQ’s Secret Weapon

If you're a jOOQ ninja, the conversion is equally smooth:

import org.jooq.lambda.Seq;

Stream<T> stream = Seq.seq(iterable);
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These libraries aren't just bells and whistles. They add extra functionality and simplify syntax, aiding your stealth operations.

Custom Spliterator for Non-Collection Iterable

If your Iterable isn't a disguise and truly isn't a Collection, a custom spliterator can give you a stealth advantage:

int characteristics = Spliterator.ORDERED | Spliterator.NONNULL;
// Who knew ORDERS could be so NONNULL-essential! 🐱‍👤
Spliterator<T> spliterator = Spliterators.spliteratorUnknownSize(iterator, characteristics);
Stream<T> stream = StreamSupport.stream(spliterator, false);
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You define Spliterator characteristics which alter stream operations, especially crucial in parallel streams.

Taming Infinite Iterables

Working with gigantic or even infinite Iterable datasets is like taming a dragon. Be cautious of your stream operations.

Stream<T> limitedStream = StreamSupport.stream(iterable.spliterator(), false).limit(100);
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This technique prevents dragon-fire-esque destruction such as out of memory errors or infinite loops.

Stream API Operations on Iterable

Sometimes, don't change Iterable to Stream. Simply use Stream API operations directly:

iterable.forEach(item -> {
    // Process each item. No need to convert Iterator to Stream, ssshhh! 🤫
});
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