OldCurmudgeon OldCurmudgeon - 7 months ago 15
Java Question

Simplest way to print an `IntStream` as a `String`

With Java-8 I can easily treat a

String
(or any
CharSequence
) as an
IntStream
using either the
chars
or the
codePoints
method.

IntStream chars = "Hello world.".codePoints();


I can then manipulate the contents of the stream

IntStream stars = chars.map(c -> c == ' ' ? ' ': '*');


I have been hunting for a tidy way to print the results and I cant even find a simple way. How do I put this stream of
int
s back into a form that can be printed like I can a
String
.

From the above
stars
I hope to print

***** ******

Answer
String result = "Hello world."
  .codePoints()
//.parallel()  // uncomment this line for large strings
  .map(c -> c == ' ' ? ' ': '*')
  .collect(StringBuilder::new,
           StringBuilder::appendCodePoint, StringBuilder::append)
  .toString();

But still, "Hello world.".replaceAll("[^ ]", "*") is simpler. Not everything benefits from lambdas.

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