Question

I have a class where on the one hand, it feels right to return an InputStream from a public method, e.g.

public class MyClass {

    private File _file;

    ...

    public InputStream getInputStream() {
        return new FileInputStream( _file );
    }
}

However, I’m also very cautious about doing this, as it puts the onus on the caller to close this stream. What ways can I potentially avoid this problem?

Answer 1

Depends on why this is a problem in your eyes. If you absolutely must return an InputStream and the file in question is not too large, you could buffer the entire file into a byte array, close the original stream and return new ByteArrayInputStream(buf). Closing a ByteArrayInputStream is not necessary (and in fact has no effect).

However, if it “feels right” to return an InputStream, does it not make sense that the caller should be expecting an InputStream, and all that goes with it, including the necessity of closing the stream when finished?