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How to stream, in java, over a key->collection map, where each streamed element is the key and every element in the c


How to stream, in java, over a key->collection map, where each streamed element is the key and every element in the c

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How to stream, in java, over a key->collection map, where each streamed element is the key and every element in the c
Tag : java , By : apple
Date : November 23 2020, 04:01 AM

Any of those help I'm trying to flatten the map but not lose the key. , You can keep the key by creating new Entrys:
keyToValuesMap.entrySet()
              .stream()
              .flatMap(entry -> entry.getValue()
                                     .stream()
                                     .map(v -> new SimpleEntry(entry.getKey(),v)))
              .forEach(entry -> printEntry(entry));

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Java 8 stream: replace single item in streamed collection


Tag : java , By : Dominique Vocat
Date : March 29 2020, 07:55 AM
Hope this helps I'm somewhat new to working in Java 8, and am refactoring some older code with (what appears to be a good use case for) a stream operation. The older code "works" but to my eyes it looks really inefficient. , You can simply do:
List<Object> newItems = items.stream()
    .map(o -> o.getPropValue() == newObject.getPropValue() ? newObject : o)
    .collect(toList());
putIntoCache(newObject.getKey(), newItems);

How to find the index of an element in a string collection using a stream in Java?


Tag : java , By : platformNomad
Date : March 29 2020, 07:55 AM
I hope this helps you . Whenever you need to use the loop index, the stream equivalent usually begins IntStream.range. In this case, the code looks like
OptionalInt index = IntStream.range(0, re.length).filter(i -> re[i].equals(text)).findFirst();
int index = Arrays.asList(re).indexOf(text); 

Java 8 Stream: How to compare current element with next element?


Tag : java , By : John Tate
Date : March 29 2020, 07:55 AM

Java 8 stream API: get first found collection element


Tag : java , By : DicksGarage
Date : March 29 2020, 07:55 AM

Iterate a collection then only one time execute stream concat all element of the collection


Tag : java , By : Naveen
Date : March 29 2020, 07:55 AM
like below fixes the issue If you want a single Stream of all the elements of all the Lists, you should use flatMap, not Stream.concat:
Stream<User> users = map.values().stream().flatMap(List::stream);
List<User> userList = map.values()
                         .stream()
                         .flatMap(List::stream)
                         .collect(Collectors.toList());
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