Question

Could anyone explain me why in the last lines, br is not recognized as variable? I’ve even tried putting br in the try clause, setting it as final, etc. Does this have anything to do with Java not support closures? I am 99% confident similar code would work in C#.

private void loadCommands(String fileName) {
    try {
        final BufferedReader br = new BufferedReader(new FileReader(fileName));

        while (br.ready()) {
            actionList.add(CommandFactory.GetCommandFromText(this, br.readLine()));
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if (br != null) br.close(); //<-- This gives error. It doesn't
                                    // know the br variable.
    }       
}

Thanks

Answer 1

Because it’s declared in the try block. Local variables are declared in one block are inaccessible in other blocks except if contained in it, i.e., the variables go out of scope when their block ends. Do this:

private void loadCommands(String fileName) {
    BufferedReader br = null;
    try {
        br = new BufferedReader(new FileReader(fileName));

        while (br.ready()) {
            actionList.add(CommandFactory.GetCommandFromText(this, br.readLine()));
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if (br != null) try { br.close(); } catch (IOException logOrIgnore) {}
    }       
}