Java Language
- Getting started with Java Language
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Java Language Streams Converting a Stream of Optional to a Stream of Values
Example
You may need to convert a Stream emitting Optional to a Stream of values, emitting only values from existing Optional. (ie: without null value and not dealing with Optional.empty()).
Optional<String> op1 = Optional.empty();
Optional<String> op2 = Optional.of("Hello World");
List<String> result = Stream.of(op1, op2)
.filter(Optional::isPresent)
.map(Optional::get)
.collect(Collectors.toList());
System.out.println(result); //[Hello World]
