Java – how should I check whether a stream is sorted?

Using Iterable < T >, it is easy to:

T last = null;
for (T t : iterable) {
    if (last != null && last.compareTo(t) > 0) {
        return false;
    }
    last = t;
}
return true;

But I can't think of a clean way to do the same thing for stream < T > This avoids consuming all elements unnecessarily

Solution

There are several ways to iterate continuous pairs of flows For example, you can view this question Of course, my favorite method is to use the library. I wrote:

boolean unsorted = StreamEx.of(sourceStream)
                           .pairMap((a,b) -> a.compareTo(b) > 0)
                           .has(true);

It is a short circuit operation: once an error is found, it will be completed Parallel flow is also good