public static void main(String args[]) throws Exception {

        final File f = new File("test.txt");
        final FileOutputStream fos = new FileOutputStream(f);


        final Thread t1 = new Thread(new Runnable() {
            @Override
            public void run() {
                synchronized (fos) {

                        [color=red]OutputStreamWriter osw = new OutputStreamWriter(fos);[/color]

                    for (int a = 0; a < 10; a++) {
                        pause(300);
                        try {
                           [color=red] osw.write("some string");[/color]
                            fos.write(44);
                            System.out.println("thread1=" + a);
                        } catch (IOException e) {
                            e.printStackTrace();
                        }

                    }

                }

            }
        });

        Thread t2 = new Thread(new Runnable() {
            @Override
            public void run() {
                synchronized (fos) {
                    for (int a = 0; a < 10; a++) {
                        pause(300);
                        try {
                            fos.write(100);
                            System.out.println("thread2=" + a);
                        } catch (IOException e) {
                            e.printStackTrace();
                        }

                    }
                }
            }
        });

        t1.start();
        t2.start();
    }