发出流的Java 8流

Question

Text1
+ continuation of Text1
+ more continuation of Text1 
Text2
+ continuation of Text2
+ more continuation of Text2
+ even more continuation of Text2

继续由\n+标记。（换行、加字符、空格作为三个字符串。）连续可以是任意行数，包括0。

我想要以下输出（每个输出都是用.foreach)打印的一行）：

Text1 continuation of Text1 more continuation of Text1 
Text2 continuation of Text2 more continuation of Text2 even more continuation of Text2

我只想使用Java流来进行转换，最好是使用Collect。有没有一种方法可以优雅地做到这一点？

Lorem ipsum dolor sit amet, consectetur 
+ adipiscing elit, sed do eiusmod tempor incididunt 
+ ut labore et dolore magna aliqua. Ut enim ad minim veniam, 
+ quis nostrud exercitation ullamco laboris nisi ut aliquip ex 
+ ea commodo consequat. 
Duis aute irure dolor in reprehenderit in voluptate velit 
+ esse cillum dolore eu fugiat nulla pariatur. Excepteur sint 
+ occaecat cupidatat non proident, sunt in culpa qui officia 
+ deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. 
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Answer 1

在Java ；9中，可以使用

static final Pattern LINE_WITH_CONTINUATION = Pattern.compile("(\\V|\\R\\+)+");

…

try(Scanner s = new Scanner(file)) {
    s.findAll(LINE_WITH_CONTINUATION)
        .map(m -> m.group().replaceAll("\\R\\+", ""))
        .forEach(System.out::println);
}

由于Java ；8缺少scanner.findAll(Pattern)方法，您可以添加该操作的自定义实现作为解决方案

public static Stream<MatchResult> findAll(Scanner s, Pattern pattern) {
    return StreamSupport.stream(new Spliterators.AbstractSpliterator<MatchResult>(
            1000, Spliterator.ORDERED|Spliterator.NONNULL) {
        public boolean tryAdvance(Consumer<? super MatchResult> action) {
            if(s.findWithinHorizon(pattern, 0)!=null) {
                action.accept(s.match());
                return true;
            }
            else return false;
        }
    }, false);
}

try(Scanner s = new Scanner(file)) {
    findAll(s, LINE_WITH_CONTINUATION)
        .map(m -> m.group().replaceAll("\\R\\+", ""))
        .forEach(System.out::println);
}