翻译代码 public static String formattedOutput(ArrayList<ECCEG.CipherPair> data) { StringBuilder sb = new StringBuilder(); for(ECCEG.CipherPair pairpoint:data){ EllipticalCurve.Point p1=pairpoint.getP1(); EllipticalCurve.Point p2=pairpoint.getP2(); sb.append("[("); sb.append(p1.getX().toString(16)); sb.append(","); sb.append(p1.getY().toString(16)); sb.append("), ("); sb.append(p2.getX().toString(16)); sb.append(","); sb.append(p2.getY().toString(16)); sb.append(")]"); sb.append("\n"); } return sb.toString(); }

这段代码的作用是将一个 ArrayList 中的数据按照一定格式进行输出。具体来说，它会遍历 ArrayList 中的每个 ECCEG.CipherPair 对象，获取其中存储的两个椭圆曲线上的点，并将它们按照 "(x1,y1), (x2,y2)" 的格式输出到 StringBuilder 中。每个输出之间会用 "[]" 包裹，并在输出的最后加上一个换行符。最终，这个方法会返回 StringBuilder 中存储的字符串。

相关问题

java8实现：将List<ADto>出力成csv文件。参数为List<ADto>、ADto.class、filePath

可以使用Java 8提供的Stream API来实现将List<ADto>输出成csv文件的功能。具体实现步骤如下：

1. 定义csv文件的列头信息。

2. 使用Stream API将List<ADto>转换为List<String[]>，其中每个String数组表示一行csv数据。

3. 使用Java 8提供的Files.write()方法将List<String[]>写入到csv文件中。

以下是完整的代码实现：

import java.io.IOException;
import java.lang.reflect.Field;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class CsvUtil {

    /**
     * 将List<ADto>输出成csv文件
     *
     * @param dataList 数据列表
     * @param clazz    数据类
     * @param filePath 文件路径
     */
    public static <T> void writeCsv(List<T> dataList, Class<T> clazz, String filePath) throws IOException {
        // 定义csv文件的列头信息
        String[] headers = getFieldNames(clazz);

        // 将List<ADto>转换为List<String[]>，其中每个String数组表示一行csv数据
        List<String[]> rows = dataList.stream()
                .map(data -> {
                    String[] row = new String[headers.length];
                    for (int i = 0; i < headers.length; i++) {
                        try {
                            Field field = clazz.getDeclaredField(headers[i]);
                            field.setAccessible(true);
                            Object value = field.get(data);
                            row[i] = value == null ? "" : value.toString();
                        } catch (ReflectiveOperationException e) {
                            e.printStackTrace();
                        }
                    }
                    return row;
                })
                .collect(Collectors.toList());

        // 将List<String[]>写入到csv文件中
        Files.write(Paths.get(filePath), encodeCsv(rows).getBytes());
    }

    /**
     * 获取类的所有字段名
     */
    private static <T> String[] getFieldNames(Class<T> clazz) {
        return Stream.of(clazz.getDeclaredFields())
                .map(Field::getName)
                .toArray(String[]::new);
    }

    /**
     * 编码csv数据
     */
    private static String encodeCsv(List<String[]> rows) {
        StringBuilder sb = new StringBuilder();
        for (String[] row : rows) {
            for (int i = 0; i < row.length; i++) {
                sb.append(row[i]);
                if (i < row.length - 1) {
                    sb.append(",");
                }
            }
            sb.append("\n");
        }
        return sb.toString();
    }
}

使用示例：

public static void main(String[] args) throws IOException {
    // 构造数据列表
    List<ADto> dataList = new ArrayList<>();
    dataList.add(new ADto("001", "foo", 20));
    dataList.add(new ADto("002", "bar", 30));

    // 输出csv文件
    CsvUtil.writeCsv(dataList, ADto.class, "output.csv");
}

其中ADto为数据类，定义如下：

public class ADto {
    private String id;
    private String name;
    private int age;

    public ADto(String id, String name, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

我想用arraylist和list方法写customer类，整篇代码需要怎么写

根据您的要求，使用 `ArrayList` 和 `List` 方法来实现 `Customer` 类。以下是完整的代码示例：

### Customer.java

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

public class Customer implements Comparable<Customer> {
    private String firstName;
    private String surname;
    private List<Ticket> tickets;

    public Customer(String firstName, String surname) {
        this.firstName = firstName;
        this.surname = surname;
        this.tickets = new ArrayList<>();
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getSurname() {
        return surname;
    }

    public void setSurname(String surname) {
        this.surname = surname;
    }

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

    public void addTicket(Ticket ticket, int quantity) {
        for (int i = 0; i < quantity; i++) {
            tickets.add(ticket);
        }
    }

    public boolean removeTicket(Ticket ticket, int quantity) {
        int count = 0;
        for (int i = 0; i < tickets.size(); i++) {
            if (tickets.get(i).equals(ticket)) {
                tickets.remove(i);
                count++;
                i--; // Adjust index after removal
                if (count == quantity) {
                    break;
                }
            }
        }
        return count == quantity;
    }

    public double getTotalCost() {
        return tickets.stream().mapToDouble(Ticket::getPrice).sum();
    }

    public double getDiscountedTotalCost() {
        int totalTickets = tickets.size();
        if (totalTickets >= 26) {
            return getTotalCost() * 0.75;
        } else if (totalTickets >= 11) {
            return getTotalCost() * 0.85;
        } else if (totalTickets >= 6) {
            return getTotalCost() * 0.90;
        }
        return getTotalCost();
    }

    @Override
    public int compareTo(Customer other) {
        int surnameComparison = this.surname.compareTo(other.surname);
        if (surnameComparison != 0) {
            return surnameComparison;
        }
        return this.firstName.compareTo(other.firstName);
    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        sb.append("Customer: ").append(firstName).append(" ").append(surname).append("\n");
        sb.append("Purchased Tickets:\n");
        for (Ticket ticket : tickets) {
            sb.append("- ").append(ticket.getName()).append(" (").append(ticket.getPrice()).append(")\n");
        }
        sb.append("Original Total Cost: ").append(getTotalCost()).append("\n");
        sb.append("Discounted Total Cost: ").append(getDiscountedTotalCost()).append("\n");
        return sb.toString();
    }
}

### Ticket.java

public class Ticket {
    private String name;
    private double price;

    public Ticket(String name, double price) {
        this.name = name;
        this.price = price;
    }

    public String getName() {
        return name;
    }

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

    public double getPrice() {
        return price;
    }

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

    @Override
    public boolean equals(Object obj) {
        if (this == obj) return true;
        if (obj == null || getClass() != obj.getClass()) return false;
        Ticket ticket = (Ticket) obj;
        return name.equals(ticket.name);
    }

    @Override
    public int hashCode() {
        return name.hashCode();
    }

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

### MainProgram.java

import java.io.*;
import java.util.*;

public class MainProgram {
    private static List<Customer> customers = new ArrayList<>();
    private static List<Ticket> tickets = new ArrayList<>();

    public static void main(String[] args) {
        loadInputData("input_data.txt");

        Scanner scanner = new Scanner(System.in);
        while (true) {
            System.out.println("Menu:");
            System.out.println("f - Finish");
            System.out.println("t - Display tickets");
            System.out.println("c - Display customers");
            System.out.println("a - Add tickets to customer");
            System.out.println("r - Remove tickets from customer");
            System.out.print("Choose an option: ");
            char option = scanner.next().charAt(0);

            switch (option) {
                case 'f':
                    System.exit(0);
                    break;
                case 't':
                    displayTickets();
                    break;
                case 'c':
                    displayCustomers();
                    break;
                case 'a':
                    addTickets(scanner);
                    break;
                case 'r':
                    removeTickets(scanner);
                    break;
                default:
                    System.out.println("Invalid option!");
            }
        }
    }

    private static void loadInputData(String filename) {
        try (BufferedReader br = new BufferedReader(new FileReader(filename))) {
            int numCustomers = Integer.parseInt(br.readLine());
            for (int i = 0; i < numCustomers; i++) {
                String[] parts = br.readLine().split(" ");
                customers.add(new Customer(parts[0], parts[1]));
            }

            int numTickets = Integer.parseInt(br.readLine());
            for (int i = 0; i < numTickets; i++) {
                String name = br.readLine();
                double price = Double.parseDouble(br.readLine());
                tickets.add(new Ticket(name, price));
            }

            double[] discounts = new double[3];
            for (int i = 0; i < 3; i++) {
                discounts[i] = Double.parseDouble(br.readLine());
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private static void displayTickets() {
        for (Ticket ticket : tickets) {
            System.out.println(ticket);
        }
    }

    private static void displayCustomers() {
        for (Customer customer : customers) {
            System.out.println(customer);
        }
    }

    private static void addTickets(Scanner scanner) {
        System.out.print("Enter customer's first name: ");
        String firstName = scanner.next();
        System.out.print("Enter customer's surname: ");
        String surname = scanner.next();

        Customer customer = findCustomer(firstName, surname);
        if (customer == null) {
            System.out.println("Customer not found!");
            return;
        }

        System.out.print("Enter ticket name: ");
        String ticketName = scanner.next();
        Ticket ticket = findTicket(ticketName);
        if (ticket == null) {
            System.out.println("Ticket not found!");
            return;
        }

        System.out.print("Enter quantity: ");
        int quantity = scanner.nextInt();

        customer.addTicket(ticket, quantity);
        System.out.println("Tickets added successfully!");
    }

    private static void removeTickets(Scanner scanner) {
        System.out.print("Enter customer's first name: ");
        String firstName = scanner.next();
        System.out.print("Enter customer's surname: ");
        String surname = scanner.next();

        Customer customer = findCustomer(firstName, surname);
        if (customer == null) {
            System.out.println("Customer not found!");
            return;
        }

        System.out.print("Enter ticket name: ");
        String ticketName = scanner.next();
        Ticket ticket = findTicket(ticketName);
        if (ticket == null) {
            System.out.println("Ticket not found!");
            return;
        }

        System.out.print("Enter quantity: ");
        int quantity = scanner.nextInt();

        if (customer.removeTicket(ticket, quantity)) {
            System.out.println("Tickets removed successfully!");
        } else {
            System.out.println("Not enough tickets to remove!");
        }
    }

    private static Customer findCustomer(String firstName, String surname) {
        for (Customer customer : customers) {
            if (customer.getFirstName().equals(firstName) && customer.getSurname().equals(surname)) {
                return customer;
            }
        }
        return null;
    }

    private static Ticket findTicket(String name) {
        for (Ticket ticket : tickets) {
            if (ticket.getName().equals(name)) {
                return ticket;
            }
        }
        return null;
    }
}

### input_data.txt

4
Pam Royal
Michael Cretu
Manfred Thiers
Sandra Cretu
5
Magpie Line
5.59
Cross City
2.50
Reiver Line
6.50
Hadrian Line
7.35
Tyne Loop
2.50
0.10
0.15
0.25

### 说明

1. **Customer 类**：实现了 `Comparable<Customer>` 接口，以便按姓氏和名字排序。包含了添加和删除票的方法，并计算总费用和折扣后的总费用。
2. **Ticket 类**：简单的票类，包含名称和价格。
3. **MainProgram 类**：主程序类，负责读取输入文件，显示菜单并处理用户的操作。
4. **input_data.txt**：输入文件格式如上所示，包含客户和票的信息。

希望这些代码能帮助您完成任务！如果有任何问题或需要进一步的帮助，请随时告诉我。