public class Rename {
public static void main(String[] args) throws IOException{

        File origine = new File(args[0]);

    renameFile(origine);


}
public static void renameFile(File fileOriginal) throws IOException{

    try {

        File tempFile = File.createTempFile("buffer", ".tmp");
        FileWriter fw = new FileWriter(tempFile);

        Reader fr = new FileReader(fileOriginal);
        BufferedReader br = new BufferedReader(fr);

        while (br.ready()) {

            fw.write(br.readLine().replace("#/A#" , "Á"));
        }

        fw.close();
        br.close();
        fr.close();

        tempFile.renameTo(fileOriginal);


    } catch (IOException e) {
        e.printStackTrace();
    }


}
}