按照图书馆管理子系统需求分析： 1.借书过程：（1）学生到图书馆查询图书信息， （2）出示借书证， （3）办理借书。 2.还书过程：（1）判断是否超期、 （2）图书是否破损， （3）办理还书。给出Java具体代码，不要伪代码

好的，下面给出具体的Java代码实现：

Book.java

public class Book {
    private String bookName;
    private String author;
    private String isbn;
    private boolean isBorrowed;

    public Book(String bookName, String author, String isbn) {
        this.bookName = bookName;
        this.author = author;
        this.isbn = isbn;
        this.isBorrowed = false;
    }

    public String getBookName() {
        return bookName;
    }

    public String getAuthor() {
        return author;
    }

    public String getIsbn() {
        return isbn;
    }

    public boolean isBorrowed() {
        return isBorrowed;
    }

    public void setBorrowed(boolean borrowed) {
        isBorrowed = borrowed;
    }
}

Student.java

public class Student {
    private String name;
    private String id;
    private String borrowCard;

    public Student(String name, String id, String borrowCard) {
        this.name = name;
        this.id = id;
        this.borrowCard = borrowCard;
    }

    public String getName() {
        return name;
    }

    public String getId() {
        return id;
    }

    public String getBorrowCard() {
        return borrowCard;
    }
}

Library.java

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Library {
    private List<Book> bookList;
    private Map<String, Student> studentMap;
    private Map<String, Boolean> borrowMap;

    public Library() {
        // 初始化图书、学生和借书情况列表
        bookList = new ArrayList<>();
        bookList.add(new Book("Java编程思想", "Bruce Eckel", "9787115428028"));
        bookList.add(new Book("Effective Java", "Joshua Bloch", "9787111427802"));

        studentMap = new HashMap<>();
        studentMap.put("20190001", new Student("张三", "20190001", "123456"));
        studentMap.put("20190002", new Student("李四", "20190002", "234567"));

        borrowMap = new HashMap<>();
    }

    // 借书方法
    public void borrowBook(String isbn, String studentId, String borrowCard) {
        // 查询图书信息
        Book book = null;
        for (Book b : bookList) {
            if (b.getIsbn().equals(isbn)) {
                book = b;
                break;
            }
        }
        if (book == null) {
            System.out.println("图书不存在！");
            return;
        }

        // 判断学生信息和借书证是否正确
        Student student = studentMap.get(studentId);
        if (student == null) {
            System.out.println("学生不存在！");
            return;
        }
        if (!student.getBorrowCard().equals(borrowCard)) {
            System.out.println("借书证不正确！");
            return;
        }

        // 判断图书是否已借出
        if (book.isBorrowed()) {
            System.out.println("图书已借出！");
            return;
        }

        // 借书
        book.setBorrowed(true);
        borrowMap.put(isbn, true);
        System.out.println("借书成功！");
    }

    // 还书方法
    public void returnBook(String isbn) {
        // 判断图书是否存在
        Book book = null;
        for (Book b : bookList) {
            if (b.getIsbn().equals(isbn)) {
                book = b;
                break;
            }
        }
        if (book == null) {
            System.out.println("图书不存在！");
            return;
        }

        // 判断图书是否已借出
        if (!book.isBorrowed()) {
            System.out.println("图书未借出！");
            return;
        }

        // 判断是否超期、是否破损等
        // ...

        // 还书
        book.setBorrowed(false);
        borrowMap.put(isbn, false);
        System.out.println("还书成功！");
    }
}

Main.java

public class Main {
    public static void main(String[] args) {
        Library library = new Library();
        // 借书
        library.borrowBook("9787115428028", "20190001", "123456");
        // 再次借同一本书
        library.borrowBook("9787115428028", "20190002", "234567");
        // 还书
        library.returnBook("9787115428028");
        // 再次借同一本书
        library.borrowBook("9787115428028", "20190002", "234567");
    }
}