New Stream API and I/O streams - Any overlap?

odoepner

I know the new Stream API is for processing object streams, often from collections.

But is this notion applicable to I/O streams, too?

It definitely seems compelling to use a functional approach to I/O streams that supports parallelism.

Let me know if my question doesn't make any sense to you

Thanks

Oliver

James_D

Indeed, there is some interplay between the APIs.

For example BufferedReader defines a lines() method that returns a (lazily-read) Stream<String>, each element being a line. The Files class in java.nio.file has a utility lines(Path path) method.

So assuming you have some class MyClass, some MyClassParser with a parse method, you can use idioms like

void processFile(Path path) throws IOException {
    MyClassParser parser = ... ;
    try (Stream<String> lines = Files.lines(path)) {
        lines.map(parser::parse).forEach( myObject -> ...);
    }
}

If you want to parallelize it, do

lines.parallel().map(parser::parse)...

(assuming your parser.parse method can handle multiple threads)