I am trying to get a count of lines that have been processed by a lambda iterating over lines in a BufferedReader.
Is there a way to get a count without writing the 2nd lambda to get just the line count?
final BufferedReader inReader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));
inReader.lines().forEach(line -> {
// do something with the line
});
Can I get a count also in the above code block? I am using Java 11.
If I understand you correctly, you want to count in your lamba. Sure, you can do that. Just initialize a count variable before executing the forEach and increase the count in your lambda block. Like this:
final BufferedReader inReader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));
// fixed the long by this
final AtomicLong counter = new AtomicLong();
inReader.lines().forEach(line -> {
counter.incrementAndGet();
// do something with the line
});
// here you can do something with the count variable, like printing it out
System.out.printf("count=%d%n", counter.get());
The forEach method comes from Iterable. It is definiately not the way I would choose to process the reader. I would do something like this:
try (BufferedReader inReader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"))) {
Stream<String> lines = inReader.lines();
long i = lines.peek(line -> {
// do something with the line
}).count();
System.out.printf("count=%d%n", i);
}
PS: Didn't really test this, so correct me if I did a mistake.
try this:
AtomicLong count = new AtomicLong();
lines.stream().forEach(line -> {
count.getAndIncrement();
// do something with line;
});