InputStream only gets to 8192 bytes

Question

I'm guessing this must be something simple I don't understand about InputStreams, but the following code only reads "README.txt" to 8192 bytes, despite the fact that fis.available() returns somewhere around 13000:
void loadDoc(){
    String str;
    try{
        InputStream is = getClass().getResourceAsStream("README.txt");
        int size = is.available();
        byte[] bytes = new byte [size];
        int read = is.read(bytes);
        System.err.println("Available:" + size + "\nRead: " + read);
        is.close();
        str = new String(bytes);
    } catch (Exception e){
        System.err.println(e);
        str = "The file README.txt could not be found; it may have been deleted or moved.\n";
    displayArea.setText(str);
    displayArea.setCaretPosition(0);
}I'm suspicious, since 8192 is a power of 2, which makes me think that it's not stopping at some arbitrary point or due to something in the file. What's going on here?

Answer 1

From what the docs for available() say, I'd have thought it would read the full 13000 or whatever. It seems like it's blocking sooner than it's supposed to.
I'd guess one of three things, in order of decreasing likelihood:
* "Blocking" has a specific meaning that doesn't extend to what's happening here, which I'd guess is simply that some underlying buffer has a size of 8k, so that's all that can be deliverd at once.
* You're not running the code you think you are, or have otherwise misinterpreted what you observed.
* There's a bug in the stream implementation.
Presumably if you loop here, you'll get the remaining bytes on the next read (if it is in fact the first point above that's causing this). Decorating the InputStream with a BufferedInputStream might do this for you, but I wouldn't count on it--you'd still have to put the reading in a loop.
On other alternative would be to turn the URL into a URI, the URI into a File, and then build a RandomAccessFile from the File, and use ReadFully. That feels like overkil to me, though.