Question

I have a method that reads text from a file; decompression may be required, depending on an input parameter:

public static String readText(File inFile, boolean compressed) {
    InputStream in = null;
    InputStreamReader isr = null;
    StringBuilder sb = new StringBuilder();//constant resizing is costly, so set the STRING_SIZE
    try {
        in = new FileInputStream(inFile);
        if (compressed) {
            in = new GZIPInputStream(in);
        }
        isr = new InputStreamReader(in);
        int length = 0;
        char[] cbuf = new char[8 * 1024];
        while ((length = isr.read(cbuf)) != -1) {
            sb.append(cbuf, 0, length);
        }
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            in.close();
        } catch (Exception e1) {
            e1.printStackTrace();
        }
    }
    return sb.toString();
}

It was suggested that I use InputStream like this so it is easier to write, and so that in the end I only have to close one thing. I am still a bit worried this might cause a memory leak. So my question is: does anyone knows if the code above is OK? Or do I have to get back to a dozen of streams and close them one by one in a finally block?

Thanks a lot.

Answer 1

Yes, closing the outermost stream/reader is sufficient.

However, your code has another potential bug: new InputStreamReader(in) will use the platform default encoding, which depends on the OS region/language settings. You should specify the encoding of the text file and use it explicitly in the constructor.