So why teach us to close duplicate?

// 在此编写你的代码
    String file;
    try {
        file = new BufferedReader(new InputStreamReader(System.in)).readLine();
    } catch (IOException e) {
        e.printStackTrace();
        return;
    }
    BufferedReader r = null;
    FileInputStream in = null;
    try {
        in = new FileInputStream(file);
        r = new BufferedReader(new InputStreamReader(in));
        String line;
        while ((line = r.readLine()) != null) System.out.println(line);
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if(r != null) {
            try {
                r.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        //TODO 需要关？？？？？？
        //before in.close() try to read and Exception Stream Closed
        //System.out.println(">>>>>>>" + in.read());
        //So why teach us to close duplicate?
        if(in != null) {
            try {
                in.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}