high-level streams and low-level streams in IO Java?

Question

I hear that: FileReader is high-level stream, BufferedReader is low-level stream, and following this website :http://way2java.com/io/chaining-of-streams/

" Rules of chaining

If streams are chained just like that, you will land in compilation errors. Following rules are to be followed.

The input for a high-level stream may come from a low-level stream or another high-level stream. That is, in programming, the constructor of a high-level stream can be passed with an object of low-level or high-level.
Being low-level, the low-level stream should work by itself. It is not entitled to get passed with any other stream"

But:

`
public class CopyLines {
public static void main(String[] args) throws IOException {

    BufferedReader inputStream = null;
    PrintWriter outputStream = null;

    try {
        inputStream = new BufferedReader(new FileReader("xanadu.txt"));// not like above website say
        outputStream = new PrintWriter(new FileWriter("characteroutput.txt"));

        String l;
        while ((l = inputStream.readLine()) != null) {
            outputStream.println(l);
        }
    } finally {
        if (inputStream != null) {
            inputStream.close();
        }
        if (outputStream != null) {
            outputStream.close();
        }
    }
}

}`

Someone tell me, why code above also correct

Following Oracle: Code is correct, but following website is contradicts — Quan Nguyen, Sep 29 '15 at 03:25
following website then: BufferedReader is low-level stream, FileReader is high-level stream. I think that FileReader can not passed as parameter for BufferedReader. — Quan Nguyen, Sep 29 '15 at 03:31
Please edit your question and quote exactly what you found from the article (the text and the link), because I can't find it. — Sotirios Delimanolis, Sep 29 '15 at 03:34
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/90840/discussion-between-quan-nguyen-and-sotirios-delimanolis). — Quan Nguyen, Sep 29 '15 at 03:38
Where does it say that a `FileReader` is a high-level stream? — Sotirios Delimanolis, Sep 29 '15 at 03:39
it say: Java comes with low-level byte streams and high-level byte streams and similarly low-level and high-level character streams. — Quan Nguyen, Sep 29 '15 at 03:43
So you deduced it was a character stream. But what kind? Low-level or high-level? What made you think it was one or the other? — Sotirios Delimanolis, Sep 29 '15 at 03:48
FileReader is high-level, BufferedReader is low-level stream, So FileReader is never parameter for BufferedReader — Quan Nguyen, Sep 29 '15 at 03:51
I don't know if it's an English thing, but I have no idea how you came to that conclusion. — Sotirios Delimanolis, Sep 29 '15 at 03:52
On the contrary - according to the rules above, `FileReader` would be the low-level one, because it only needs a file to work. `BufferedReader` would be high-level, because it needs another `Reader` to work - it just provides the buffering. — Cinnam, Sep 29 '15 at 04:05
@Cinnam: You say is correct.. Because i deduced from hierachy, so i was confused — Quan Nguyen, Sep 29 '15 at 04:13
"Low level" means "low on the OSI protocol stack" e.g. something that deals in machine architecture: byte data, character encoding, pipes, etc. It does not imply a coupling constraint. A low level stream, for example, a bufferedReader, can receive data from another low-level stream, an InputStreamReader. "High level" means it deals in application-level stuff: converting objects to data, vice versa, etc. A stream assembly can combine both low-level and high level components into one stream. — John, Jun 06 '21 at 16:45

high-level streams and low-level streams in IO Java?

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