try resource并不适用于返回流的情况

try resource作用域只在try的内部，超过范围，流就已经关闭

    public static void main(String[] args) {
        App app = new App();
        app.test();
    }

    public void test(){
        FileInputStream stream = getStream1();
        try {
            int read = stream.read();
            System.out.println(read);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public FileInputStream getStream(){
        try {
            FileInputStream fileInputStream = new FileInputStream(".gitignore");
            return fileInputStream;
        }catch (Exception e){
            e.printStackTrace();
        }
        return null;
    }

    /**
     * java.io.IOException: Stream Closed
     *  at java.io.FileInputStream.read0(Native Method)
     *  at java.io.FileInputStream.read(FileInputStream.java:207)
     *  at com.tony.puzzle.App.test(App.java:17)
     *  at com.tony.puzzle.App.main(App.java:11)
     * @return
     */
    public FileInputStream getStream1(){
        try (FileInputStream fileInputStream = new FileInputStream(".gitignore");){
            return fileInputStream;
        }catch (Exception e){
            e.printStackTrace();
        }
        return null;
    }