Java序列化问题：ArrayList添加Book时String转Author类型不兼容求助

我尝试序列化多个对象，但向ArrayList<Book>添加元素时始终报错，books.add代码行提示不兼容的类型：String无法转换为Author。我试过把所有内容转成String但没用，想知道怎么把String转换成Author对象？我的目标是创建包含5个Book对象的ArrayList，涉及Author、Book、PubDate三个类，目前卡在Book类添加元素时的String转Author对象问题上。

Book类 #

public class Book {
    private String bookTitle;
    private Author name;
    private PubDate date;

    public Book() {
    }

    public Book(String bookTitle, Author name, PubDate date) {
        this.bookTitle = bookTitle;
        this.name = name;
        this.date = date;
    }

    public String getBookTitle() {
        return bookTitle;
    }

    public Author getName() {
        return name;
    }

    public PubDate getDate() {
        return date;
    }

    public void setBookTitle(String bookTitle) {
        this.bookTitle = bookTitle;
    }

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

    public void setDate(PubDate date) {
        this.date = date;
    }

    @Override
    public String toString() {
        return "Book{" + "bookTitle=" + bookTitle + ", name=" + name + ", date=" + date + '}';
    }
}

Author类 #

public class Author {
    private String firstname;
    private String lastname;
    private String title;

    public Author() {
    }

    public Author(String firstname, String lastname, String title) {
        this.firstname = firstname;
        this.lastname = lastname;
        this.title = title;
    }

    public String getFirstname() {
        return firstname;
    }

    public String getLastname() {
        return lastname;
    }

    public String getTitle() {
        return title;
    }

    public void setFirstname(String firstname) {
        this.firstname = firstname;
    }

    public void setLastname(String lastname) {
        this.lastname = lastname;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    @Override
    public String toString() {
        return "Author{" + "firstname=" + firstname + ", lastname=" + lastname + ", title=" + title + '}';
    }
}

Serialization类 #

public class Serialization {
    public static void main(String[] args) {
        ArrayList<Book> books = new ArrayList<Book>();
        ArrayList<Author> authors = new ArrayList<Author>();
        ArrayList<PubDate> pubs = new ArrayList<PubDate>();
        
        books.add(new Book("Book Title", "Author Name", "Publishing Date"));
    }
}

问题出在你调用Book构造方法时，传入的第二个参数是字符串"Author Name"，但构造方法要求的是Author类型的对象；第三个参数字符串"Publishing Date"也不符合PubDate类型的要求。要解决这个问题，你需要先创建Author和PubDate对象，再传入Book的构造方法。

1. 直接创建Author对象传入 #

如果知道作者的名、姓和头衔，直接用Author的构造方法实例化对象：

// 创建Author对象
Author author1 = new Author("John", "Doe", "Mr.");
// 假设PubDate有类似的构造方法（根据你的PubDate类实现调整参数）
PubDate pubDate1 = new PubDate("2024", "05", "20");
// 添加Book到集合
books.add(new Book("Book Title", author1, pubDate1));

2. 从单个字符串解析生成Author对象 #

如果只有类似"Author Name"的字符串，需要先拆分字符串提取作者信息，再创建对象。比如拆分出名和姓：

String authorStr = "Author Name";
String[] nameParts = authorStr.split(" ");
// 假设拆分后第一个是名，第二个是姓，头衔默认空或自定义
Author author2 = new Author(nameParts[0], nameParts[1], "");
PubDate pubDate2 = new PubDate("2024", "05", "21");
books.add(new Book("Second Book", author2, pubDate2));

按照这个方式，你可以创建5个对应的Author和PubDate对象，逐个添加到books集合中。

内容的提问来源于stack exchange，提问作者Jermong