public class Book {  //定义Book类

    private String bookName;  //书名
    private String author;   //作者
    private String publisher;  //出版社
    private String publishDate;  //出版日期

    public Book(String bookName, String author, String publisher, String publishDate) {  //构造方法
        this.setBookName(bookName);
        this.setAuthor(author);
        this.setPublisher(publisher);
        this.setPublishDate(publishDate);
    }
    public void setBookName(String bookName) {
        this.bookName = bookName;
    }
    public String getBookName() {
        return bookName;
    }
    public void setAuthor(String author) {
        this.author = author;
    }
    public String getAuthor() {
        return author;
    }
    public void setPublisher(String publisher) {
        this.publisher = publisher;
    }
    public String getPublisher() {
        return publisher;
    }
    public void setPublishDate(String publishDate) {
        this.publishDate = publishDate;
    }
    public String getPublishDate() {
        return publishDate;
    }
    public String toString() {
        return "书名：" + this.getBookName() + "\n\t" + "作者：" + this.getAuthor() +
                "\n\t" + "出版社：" + this.getPublisher() + "\n\t" + "出版日期：" + this.getPublishDate();
    }
    public static void main(String[] args) {
            Book b1 = new Book("书名1", "作者1", "出版社1", "2010-01-01");
            System.out.println(b1);
            Book b2 = new Book("书名2", "作者2", "出版社2", "2010-02-02");
            System.out.println(b2);
            Book b3 = new Book("书名3", "作者3", "出版社3", "2010-03-03");
            System.out.println(b3);
    }
}
}}