用Java写一个电影网上购票系统的全部代码，要求具备文件读写功能，程序中的数据要以文件方式保存，程序中要求具备异常处理

好的，下面是一个可能的实现，注意这只是一个参考代码，你可以根据自己的需求进行修改和扩展：

MovieTicket.java

import java.util.Date;

public class MovieTicket {
    private String movieName;   // 电影名称
    private String cinemaName;  // 影院名称
    private Date dateTime;      // 放映时间
    private int seatNumber;     // 座位号
    private double price;       // 价格

    public MovieTicket(String movieName, String cinemaName, Date dateTime, int seatNumber, double price) {
        this.movieName = movieName;
        this.cinemaName = cinemaName;
        this.dateTime = dateTime;
        this.seatNumber = seatNumber;
        this.price = price;
    }

    public String getMovieName() {
        return movieName;
    }

    public void setMovieName(String movieName) {
        this.movieName = movieName;
    }

    public String getCinemaName() {
        return cinemaName;
    }

    public void setCinemaName(String cinemaName) {
        this.cinemaName = cinemaName;
    }

    public Date getDateTime() {
        return dateTime;
    }

    public void setDateTime(Date dateTime) {
        this.dateTime = dateTime;
    }

    public int getSeatNumber() {
        return seatNumber;
    }

    public void setSeatNumber(int seatNumber) {
        this.seatNumber = seatNumber;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "MovieTicket{" +
                "movieName='" + movieName + '\'' +
                ", cinemaName='" + cinemaName + '\'' +
                ", dateTime=" + dateTime +
                ", seatNumber=" + seatNumber +
                ", price=" + price +
                '}';
    }
}

Cinema.java

import java.util.ArrayList;
import java.util.List;

public class Cinema {
    private String name;            // 影院名称
    private List<MovieTicket> tickets;   // 影院售出的电影票

    public Cinema(String name) {
        this.name = name;
        this.tickets = new ArrayList<>();
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public List<MovieTicket> getTickets() {
        return tickets;
    }

    public void setTickets(List<MovieTicket> tickets) {
        this.tickets = tickets;
    }

    public void addTicket(MovieTicket ticket) {
        tickets.add(ticket);
    }

    public void removeTicket(MovieTicket ticket) {
        tickets.remove(ticket);
    }

    @Override
    public String toString() {
        return "Cinema{" +
                "name='" + name + '\'' +
                ", tickets=" + tickets +
                '}';
    }
}

MovieTicketSystem.java

import java.io.*;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class MovieTicketSystem {
    private List<Cinema> cinemas;   // 所有影院

    public MovieTicketSystem() {
        this.cinemas = new ArrayList<>();
    }

    public void addCinema(Cinema cinema) {
        cinemas.add(cinema);
    }

    public void removeCinema(Cinema cinema) {
        cinemas.remove(cinema);
    }

    public void sellTicket(MovieTicket ticket, Cinema cinema) throws Exception {
        // 判断票是否已经售出
        if (cinema.getTickets().contains(ticket)) {
            throw new Exception("该电影票已经售出！");
        }
        // 判断座位是否已经被占用
        for (MovieTicket t : cinema.getTickets()) {
            if (t.getDateTime().equals(ticket.getDateTime())
                    && t.getSeatNumber() == ticket.getSeatNumber()) {
                throw new Exception("该座位已经被占用！");
            }
        }
        cinema.addTicket(ticket);
    }

    public List<MovieTicket> getTickets(Cinema cinema) {
        return cinema.getTickets();
    }

    public List<MovieTicket> getTicketsByMovie(String movieName) {
        List<MovieTicket> result = new ArrayList<>();
        for (Cinema cinema : cinemas) {
            for (MovieTicket ticket : cinema.getTickets()) {
                if (ticket.getMovieName().equals(movieName)) {
                    result.add(ticket);
                }
            }
        }
        return result;
    }

    public List<MovieTicket> getTicketsByCinema(String cinemaName) {
        for (Cinema cinema : cinemas) {
            if (cinema.getName().equals(cinemaName)) {
                return cinema.getTickets();
            }
        }
        return null;
    }

    public void saveToFile(String fileName) throws IOException {
        try (PrintWriter writer = new PrintWriter(new FileWriter(fileName))) {
            for (Cinema cinema : cinemas) {
                for (MovieTicket ticket : cinema.getTickets()) {
                    writer.println(String.format("%s,%s,%s,%d,%.2f",
                            ticket.getMovieName(),
                            cinema.getName(),
                            new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(ticket.getDateTime()),
                            ticket.getSeatNumber(),
                            ticket.getPrice()));
                }
            }
        }
    }

    public void loadFromFile(String fileName) throws IOException, ParseException {
        cinemas.clear();
        try (BufferedReader reader = new BufferedReader(new FileReader(fileName))) {
            String line;
            while ((line = reader.readLine()) != null) {
                String[] fields = line.split(",");
                String movieName = fields[0];
                String cinemaName = fields[1];
                Date dateTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse(fields[2]);
                int seatNumber = Integer.parseInt(fields[3]);
                double price = Double.parseDouble(fields[4]);
                MovieTicket ticket = new MovieTicket(movieName, cinemaName, dateTime, seatNumber, price);
                Cinema cinema = null;
                for (Cinema c : cinemas) {
                    if (c.getName().equals(cinemaName)) {
                        cinema = c;
                        break;
                    }
                }
                if (cinema == null) {
                    cinema = new Cinema(cinemaName);
                    cinemas.add(cinema);
                }
                cinema.addTicket(ticket);
            }
        }
    }

    @Override
    public String toString() {
        return "MovieTicketSystem{" +
                "cinemas=" + cinemas +
                '}';
    }
}

使用示例：

public class Main {
    public static void main(String[] args) throws Exception {
        MovieTicketSystem system = new MovieTicketSystem();

        // 添加影院
        Cinema cinema1 = new Cinema("万达影城");
        Cinema cinema2 = new Cinema("星美国际影城");
        system.addCinema(cinema1);
        system.addCinema(cinema2);

        // 售出电影票
        MovieTicket ticket1 = new MovieTicket("复仇者联盟4", "万达影城", new Date(), 10, 50.0);
        MovieTicket ticket2 = new MovieTicket("流浪地球", "星美国际影城", new Date(), 20, 40.0);
        system.sellTicket(ticket1, cinema1);
        system.sellTicket(ticket2, cinema2);

        // 获取电影票
        List<MovieTicket> tickets1 = system.getTickets(cinema1);
        List<MovieTicket> tickets2 = system.getTicketsByMovie("流浪地球");
        List<MovieTicket> tickets3 = system.getTicketsByCinema("万达影城");

        // 保存和加载数据
        system.saveToFile("data.txt");
        system.loadFromFile("data.txt");

        System.out.println(system);
    }
}

希望这个实现能够对你有所帮助！