how to access outer variable in Java Callback function

i develop a little playframework project and use jpa in a inner block like this:

private void sendMailToTheRegulator(final Machine mc, String rea) {
    List<LogProject> pros = null;
    try {
        pros = JPA.withTransaction(new Function0<List<LogProject>>() {
            @Override
            public List<LogProject> apply() throws Throwable {
                List<ServerModel> ss = JPA.em()
                        .createQuery("from ServerModel where machineId=")
                        .setParameter(1, mc.getId()).getResultList();
...
}

the mc does not exist in apply() so i cannot access its id. when i execute the codes it throws that the mc.getId() is null.
what should i do to fix it?