Book(string name, string author, string publisher, string date, double price, int id) : book_name(name), author(author), publisher(publisher), publish_date(date), price(price), book_id(id) {}这个是什么意思

这是一个C++中的构造函数，用于创建一个名为Book的类的对象。构造函数包含了六个参数，分别是书名(name)、作者(author)、出版社(publisher)、出版日期(date)、价格(price)、书的编号(id)。在构造函数中，使用了初始化列表来初始化Book类中的成员变量(book_name, author, publisher, publish_date, price和book_id)。这样构造函数被调用时，它会自动将传入的参数赋值给对应的成员变量。

相关问题

class Book { private: // 图书编号 int book_id; // 书名 string book_name; // 作者 string author; // 出版社 string publisher; // 出版日期 string publish_date; // 价格 double price; 帮我写一份构造方法

好的，根据这个类的成员变量，这里给出一个构造函数的例子：

class Book {
private:
    // 图书编号
    int book_id;
    // 书名
    string book_name;
    // 作者
    string author;
    // 出版社
    string publisher;
    // 出版日期
    string publish_date;
    // 价格
    double price;

public:
    // 构造函数
    Book(int id, string name, string author, string publisher, string date, double price) {
        book_id = id;
        book_name = name;
        this->author = author; // 使用this指针来区分成员变量和参数同名的情况
        this->publisher = publisher;
        publish_date = date;
        this->price = price;
    }
};

这个构造函数包含了6个参数，它们分别对应了类的6个私有成员变量。在函数内部，使用了赋值语句来初始化每一个成员变量。在第10行，使用了this指针来区分成员变量和参数同名的情况。这样，当构造函数被调用时，它会自动将传入的参数赋值给对应的成员变量。

实现： 1.修改该文档，将Reader类通通用String定义 2.将文档里的读写方法按文档里所给的“读写方法模板”进行修改

### 修改后的文档

#### 1. 将 `Reader` 类中的所有字段类型从 `long` 改为 `String`

package com.zrgj;

public class Reader {
    private String r_id;
    private String r_name;
    private String r_cardid;
    private String aphone;
    private String r_password;
    private boolean hasOverdueFee;

    public Reader() {}

    public Reader(String r_id, String r_name, String r_cardid, String aphone, String r_password) {
        this.r_id = r_id;
        this.r_name = r_name;
        this.r_cardid = r_cardid;
        this.aphone = aphone;
        this.r_password = r_password;
        this.hasOverdueFee = false;
    }

    // Getters and Setters
    public String getR_id() { return r_id; }
    public void setR_id(String r_id) { this.r_id = r_id; }
    public String getR_name() { return r_name; }
    public void setR_name(String r_name) { this.r_name = r_name; }
    public String getR_cardid() { return r_cardid; }
    public void setR_cardid(String r_cardid) { this.r_cardid = r_cardid; }
    public String getAphone() { return aphone; }
    public void setAphone(String aphone) { this.aphone = aphone; }
    public String getR_password() { return r_password; }
    public void setR_password(String r_password) { this.r_password = r_password; }
    public boolean hasOverdueFee() { return hasOverdueFee; }
    public void setHasOverdueFee(boolean hasOverdueFee) { this.hasOverdueFee = hasOverdueFee; }

    @Override
    public String toString() {
        return "Reader [r_id=" + r_id + ", r_name=" + r_name + ", r_cardid=" + r_cardid + ", aphone=" + aphone + ", r_password=" + r_password + "]";
    }
}

#### 2. 修改 `Tools` 类中的读写方法，使其符合文档中的“读写方法模板”

package com.zrgj;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;

public class Tools {
    public static final String reader_file_path = System.getProperty("user.home") + "/Desktop/Reader.txt";
    public static final String books_file_path = System.getProperty("user.home") + "/Desktop/Book.txt";

    public static String readFile(String filePath) throws IOException {
        File myFile = createFileObj(filePath);
        StringBuilder result = new StringBuilder();
        try (BufferedReader br = new BufferedReader(new FileReader(myFile))) {
            String s;
            while ((s = br.readLine()) != null) {
                result.append(s).append("\n");
            }
        }
        return result.toString();
    }

    public static void writeFile(String content, String filePath) throws IOException {
        File file = createFileObj(filePath);
        try (BufferedWriter writer = new BufferedWriter(new FileWriter(file))) {
            writer.write(content);
        }
    }

    public static File createFileObj(String filePath) {
        return new File(filePath);
    }

    public static String arrToString(ArrayList<Reader> readerArr) {
        StringBuilder sb = new StringBuilder();
        for (Reader reader : readerArr) {
            sb.append(reader.getR_id()).append(",")
              .append(reader.getR_name()).append(",")
              .append(reader.getR_cardid()).append(",")
              .append(reader.getAphone()).append(",")
              .append(reader.getR_password()).append(",")
              .append(reader.hasOverdueFee()).append("\n");
        }
        return sb.toString();
    }

    public static ArrayList<Reader> strToArr(String content) {
        ArrayList<Reader> readers = new ArrayList<>();
        String[] lines = content.split("\n");
        for (String line : lines) {
            String[] parts = line.split(",");
            if (parts.length == 6) {
                readers.add(new Reader(parts[0], parts[1], parts[2], parts[3], parts[4]));
                readers.get(readers.size() - 1).setHasOverdueFee(Boolean.parseBoolean(parts[5]));
            }
        }
        return readers;
    }

    public static void addNewReader(Reader reader) throws IOException {
        ArrayList<Reader> readers = strToArr(readFile(reader_file_path));
        readers.add(reader);
        writeFile(arrToString(readers), reader_file_path);
        System.out.println("添加成功");
    }

    public static Reader findReaderById(String r_id) throws IOException {
        ArrayList<Reader> readers = strToArr(readFile(reader_file_path));
        for (Reader reader : readers) {
            if (reader.getR_id().equals(r_id)) {
                return reader;
            }
        }
        return null;
    }

    public static boolean updatePassword(String r_id, String newPassword) throws IOException {
        ArrayList<Reader> readers = strToArr(readFile(reader_file_path));
        for (Reader reader : readers) {
            if (reader.getR_id().equals(r_id)) {
                reader.setR_password(newPassword);
                writeFile(arrToString(readers), reader_file_path);
                return true;
            }
        }
        return false;
    }

    public static boolean deleteReader(String r_id) throws IOException {
        ArrayList<Reader> readers = strToArr(readFile(reader_file_path));
        for (int i = 0; i < readers.size(); i++) {
            if (readers.get(i).getR_id().equals(r_id)) {
                readers.remove(i);
                writeFile(arrToString(readers), reader_file_path);
                return true;
            }
        }
        return false;
    }

    public static ArrayList<Book> readBooksFromFile() throws IOException {
        File file = new File(books_file_path);
        if (!file.exists()) {
            return new ArrayList<>();
        }
        ArrayList<Book> books = new ArrayList<>();
        try (BufferedReader br = new BufferedReader(new FileReader(file))) {
            String line;
            while ((line = br.readLine()) != null) {
                String[] data = line.split(",");
                if (data.length == 7) {
                    String b_id = data[0];
                    String b_name = data[1];
                    String author = data[2];
                    String publisher = data[3];
                    String category = data[4];
                    double price = Double.parseDouble(data[5]);
                    boolean isReserved = Boolean.parseBoolean(data[6]);
                    Book book = new Book(b_id, b_name, author, publisher, category, price);
                    book.setReserved(isReserved);
                    books.add(book);
                }
            }
        }
        return books;
    }

    public static void writeBooksToFile(ArrayList<Book> books) throws IOException {
        BufferedWriter bw = new BufferedWriter(new FileWriter(books_file_path));
        for (Book book : books) {
            bw.write(book.getB_id() + "," +
                     book.getB_name() + "," +
                     book.getAuthor() + "," +
                     book.getPublisher() + "," +
                     book.getCategory() + "," +
                     book.getPrice() + "," +
                     book.isReserved() + "\n");
        }
        bw.close();
    }

    public static void markBookAsReserved(String b_id) throws IOException {
        ArrayList<Book> books = readBooksFromFile();
        for (Book book : books) {
            if (book.getB_id().equals(b_id)) {
                book.setReserved(true);
                writeBooksToFile(books);
                return;
            }
        }
    }

    public static void markBookAsUnreserved(String b_id) throws IOException {
        ArrayList<Book> books = readBooksFromFile();
        for (Book book : books) {
            if (book.getB_id().equals(b_id)) {
                book.setReserved(false);
                writeBooksToFile(books);
                return;
            }
        }
    }

    // 读取借阅文件
    public static ArrayList<BorrowReturn> readFromBorrowFile() throws IOException, ParseException {
        ArrayList<BorrowReturn> borrowReturns = new ArrayList<>();
        BufferedReader br = new BufferedReader(new FileReader("BorrowReturn.txt"));
        String line;
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        while ((line = br.readLine()) != null) {
            String[] parts = line.split(",");
            if (parts.length >= 4) { // 至少要有四个字段（bookid, bookname, readerid, borrowdate）
                String bookid = parts[0];
                String bookname = parts[1];
                String readerid = parts[2];
                Date borrowdate = sdf.parse(parts[3]);
                Date returndate = null;
                Date actualreturn = null;
                if (parts.length > 4 && !parts[4].isEmpty()) {
                    returndate = sdf.parse(parts[4]);
                }
                if (parts.length > 5 && !parts[5].isEmpty()) {
                    actualreturn = sdf.parse(parts[5]);
                }
                BorrowReturn br1 = new BorrowReturn();
                br1.setBookid(bookid);
                br1.setBookname(bookname);
                br1.setReaderid(readerid);
                br1.setBorrowdate(borrowdate);
                br1.setReturndate(returndate);
                br1.setActualreturn(actualreturn);
                borrowReturns.add(br1);
            } else {
                // 可以选择记录日志、跳过这一行或抛出异常
                System.err.println("Invalid line format: " + line);
            }
        }
        br.close();
        return borrowReturns;
    }

    // 写借阅文件
    public static void writeToBorrowFile(ArrayList<BorrowReturn> borrowReturns) throws IOException {
        BufferedWriter bw = new BufferedWriter(new FileWriter("BorrowReturn.txt"));
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        for (BorrowReturn br : borrowReturns) {
            String borrowDateString = sdf.format(br.getBorrowdate());
            String returnDateString = (br.getReturndate() != null) ? sdf.format(br.getReturndate()) : "";
            String actualReturnDateString = (br.getActualreturn() != null) ? sdf.format(br.getActualreturn()) : "";
            bw.write(br.getBookid() + "," +
                     br.getBookname() + "," +
                     br.getReaderid() + "," +
                     borrowDateString + "," +
                     returnDateString + "," +
                     actualReturnDateString + "," + "\n");
        }
        bw.close();
    }

    // 写入座位文件
    public static void writeToSeatFile(ArrayList<Seat> seats) throws IOException {
        BufferedWriter bw = new BufferedWriter(new FileWriter("Seat.txt"));
        for (Seat s : seats) {
            bw.write(s.getId() + "," + s.getLocation() + "," + s.getStatus() + "," + "\n");
        }
        bw.close();
    }

    // 读取座位文件
    public static ArrayList<Seat> readFromSeatFile() throws IOException {
        ArrayList<Seat> seats = new ArrayList<>();
        BufferedReader br = new BufferedReader(new FileReader("Seat.txt"));
        String line;
        while ((line = br.readLine()) != null) {
            String[] parts = line.split(",");
            if (parts.length == 3) { // 至少要有3个字段（id, location, status）
                String id = parts[0];
                String location = parts[1];
                String status = parts[2];
                Seat s = new Seat();
                s.setId(id);
                s.setLocation(location);
                s.setStatus(status);
                seats.add(s);
            } else {
                // 可以选择记录日志、跳过这一行或抛出异常
                System.err.println("Invalid line format: " + line);
            }
        }
        br.close();
        return seats;
    }
}

### 总结

1. **修改 `Reader` 类**：
- 将 `aphone` 字段从 `long` 改为 `String`。
- 更新相应的 getter 和 setter 方法。

2. **修改 `Tools` 类中的读写方法**：
- 读取和写入借阅文件的方法 `readFromBorrowFile` 和 `writeToBorrowFile` 已经按照模板进行了修改。
- 读取和写入座位文件的方法 `readFromSeatFile` 和 `writeToSeatFile` 也已经按照模板进行了修改。

这些修改确保了代码的一致性和正确性。