SpringBoot控制台版图书借阅程序

package com.book;

import com.book.dao.BookMapper;
import com.book.dao.StudentMapper;
import com.book.dao.lendingRecordMapper;
import com.book.model.Book;
import com.book.model.Student;
import com.book.model.lendingRecord;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;
import java.util.Scanner;

@SpringBootApplication
@MapperScan("com.book.dao")
public class MyApplication implements CommandLineRunner {

    @Autowired
    private BookMapper bookMapper;

    @Autowired
    private StudentMapper studentMapper;

    @Autowired
    private lendingRecordMapper lendingRecordMapper;

    public static void main(String[] args) {
        SpringApplication.run(MyApplication.class, args);
    }

    @Override
    public void run(String... strings) throws Exception {
        serve();
    }

    private void serve() {
        Scanner scan = new Scanner(System.in);
        int command;
        while (true) {
            System.out.println("=======分===割===线================");
            System.out.println("请问你要干嘛？");
            System.out.println("1、管理书");
            System.out.println("2、管理用户");
            System.out.println("3、借书");
            System.out.println("4、还书");
            System.out.println("5、退出程序");
            command = scan.nextInt();
            if (command == 1) {
                System.out.println("请问你下一步要干嘛？");
                System.out.println("1、增书");
                System.out.println("2、改书");
                System.out.println("3、删书");
                System.out.println("4、查书");
                System.out.println("5、浏览书");
                command = scan.nextInt();
                if (command == 1) {
                    System.out.println("1、请你依次输入书的书名、作者、出版社、ISBN号、数量");
                    System.out.println("注意一行一个：");
                    scan.nextLine();
                    String name = scan.nextLine();
                    System.out.println("书名" + name + "已录入。");
                    String author = scan.nextLine();
                    String press = scan.nextLine();
                    String isbn = scan.nextLine();
                    int num = scan.nextInt();
                    Book book = new Book(name, author, press, isbn, num);
                    bookMapper.insert(book);
                    System.out.println(book + "已录入！！！");
                } else if (command == 2) {
                    System.out.println("想改书？请填入书的id以及欲改字段");
                    System.out.print("书的id：");
                    long id = scan.nextLong();
                    System.out.print("书名：");
                    String name = scan.next();
                    System.out.print("作者：");
                    String author = scan.next();
                    System.out.print("出版社：");
                    String press = scan.next();
                    System.out.print("isbn：");
                    String isbn = scan.next();
                    System.out.print("数量：");
                    int num = scan.nextInt();
                    Book book = new Book(name, author, press, isbn, num);
                    book.setId(id);
                    System.out.println(book + "修改成功！！！");
//                bookMapper.updateByPrimaryKeySelective();
                } else if (command == 3) {
                    System.out.println("你想删书？请直接输入书的id：");
                    long id = scan.nextLong();
                    System.out.println("恭喜你，删除成功！！！");
                } else if (command == 4) {
                    System.out.println("你想查书？请直接输入书的id：");
                    long id = scan.nextLong();
                    Book book = bookMapper.selectByPrimaryKey(id);
                    if (book == null) {
                        System.out.println("不好意思没有这本书");
                    } else {
                        System.out.println("找到这本书了，信息如下：");
                        System.out.println(book);
                    }
                } else if (command == 5) {
                    List<Book> list = bookMapper.selectAll();
                    for (Book x : list) {
                        System.out.println(x);
                    }
                }
            } else if (command == 2) {
                System.out.println("请问你下一步要干嘛？");
                System.out.println("1、增用户");
                System.out.println("2、改用户");
                System.out.println("3、删用户");
                System.out.println("4、查用户");
                System.out.println("5、浏览用户");
                command = scan.nextInt();
                if (command == 1) {
                    System.out.println("1、请你依次输入用户的身份证号码、姓名、出生年月、性别");
                    System.out.println("注意一行一个：");
                    scan.nextLine();
                    String idCard = scan.nextLine();
                    System.out.println("idCard" + idCard + "已录入。");
                    String name = scan.nextLine();
                    String birth = scan.nextLine();
                    String sex = scan.nextLine();
                    Student student = new Student(name, sex, idCard, birth);
                    studentMapper.insert(student);
                    System.out.println(student + "已录入！！！");
                } else if (command == 2) {
                    System.out.println("想改用户？请填入用户的id以及欲改字段");
                    System.out.print("用户的id：");
                    long id = scan.nextLong();
                    System.out.print("身份证号码：");
                    String idCard = scan.next();
                    System.out.print("姓名：");
                    String name = scan.next();
                    System.out.print("性别：");
                    String sex = scan.next();
                    System.out.print("出生年月：");
                    String birth = scan.next();
                    Student student = new Student(name, sex, idCard, birth);
                    student.setId(id);
                    System.out.println(student + "修改成功！！！");
//                bookMapper.updateByPrimaryKeySelective();
                } else if (command == 3) {
                    System.out.println("你想删用户？请直接输入用户的id：");
                    long id = scan.nextLong();
                    System.out.println("恭喜你，删除成功！！！");
                } else if (command == 4) {
                    System.out.println("你想查用户？请直接输入用户的id：");
                    long id = scan.nextLong();
                    Student student = studentMapper.selectByPrimaryKey(id);
                    if (student == null) {
                        System.out.println("不好意思没有这个用户");
                    } else {
                        System.out.println("找到这个用户了，信息如下：");
                        System.out.println(student);
                    }
                } else if (command == 5) {
                    List<Student> list = studentMapper.selectAll();
                    for (Student x : list) {
                        System.out.println(x);
                    }
                }
            } else if (command == 3) {
                System.out.print("读者id：");
                Long uid = scan.nextLong();
                System.out.print("书的id：");
                Long bookId = scan.nextLong();
                System.out.print("借书本数：");
                int num = scan.nextInt();
                borrowBooks(uid, bookId, num);
            } else if (command == 4) {
                System.out.print("读者id：");
                Long uid = scan.nextLong();
                System.out.print("书的id：");
                Long bookId = scan.nextLong();
                returnBooks(uid, bookId);
            } else if (command == 5) {
                break;
            }
        }
    }

    @Transactional
    private void borrowBooks(Long uid, Long bookId, int num) {
        Student student = studentMapper.selectByPrimaryKey(uid);
        if (student == null) {
            System.out.println("读者身份有错！！！请检查一遍再重新输入");
            return;
        }
        Book book = bookMapper.selectByPrimaryKey(bookId);
        if (book == null || book.getNum() < num) {
            System.out.println("书籍不存在或者数量不够！！！");
            return;
        }
        book.setNum(book.getNum() - num);
        bookMapper.updateByPrimaryKey(book);
        System.out.println("书籍数量已更新");
        lendingRecord record = lendingRecordMapper.selectByUidAndBookId(uid, bookId);
        if (record != null) {
            // 如果借过同类的书，那就更新记录
            record.setNum(record.getNum() + num);
            lendingRecordMapper.updateByPrimaryKey(record);
        } else {
            // 如果没有，创建新记录
            record = new lendingRecord(uid, bookId, num);
            lendingRecordMapper.insert(record);
        }
        System.out.println("恭喜你！借书成功咯！要提醒读者按时还书哦！");
    }

    @Transactional
    private void returnBooks(Long uid, Long bookId) {
        // 可能出现Expected one result (or null) to be returned by selectOne(), but found: 2
        // 需要保证数据干净
        lendingRecord record = lendingRecordMapper.selectByUidAndBookId(uid, bookId);
        if (record == null) {
            System.out.println("不好意思，查不到该条借书记录~");
        } else {
            // 增加库存
            Book book = bookMapper.selectByPrimaryKey(bookId);
            book.setNum(book.getNum() + record.getNum());
            bookMapper.updateByPrimaryKey(book);
            // 删除记录
            lendingRecordMapper.deleteByPrimaryKey(record.getId());
            System.out.println("恭喜你，还书成功~~~");
            System.out.println("^o^");
        }
    }
}