class writer {
    public void persistData() {
        // code to read file and created object for each table
        // size of file here is 3 so loop is running 3 times and table1Object
        // and table2Object and table3Object has rows to be inserted into
        // database table A,B,C
        for (int i = 0; i < 3; i++) {
            service.persistData(table1Object[i], table2Object, table3Oject[i]);

        }
    }
}

class service {
    @Transactional(propagation = Propagation.REQUIRED_NEW, readOnly = false)
    public void persistData(ob1,ob2,ob3){
        dao.insertionOrUpadteForTableA(ob1);
        dao.insertionOrUpadteForTableB(ob2);
        dao.insertionOrUpadteForTableC(ob3);

    }
}