Scala图书管理系统

张裕 · 2024-12-31 10:55:49

package org.app
package dao
import org.app.models.BookModel
import scala.collection.mutable.ListBuffer
//图书，数据操作层
class BookDAO {
//加载图书，从文件中读入
def loadBooks(): ListBuffer[BookModel] = {
val books = new ListBuffer[BookModel]()
val source = scala.io.Source.fromFile("books.txt")
for(line <- source.getLines()){
println(line)
val Array(id, name, author, available) = line.split(",")
//实例化一本书，保存到List
books += BookModel(id.toInt, name, author, available.toBoolean)
}
//关闭连接
source.close()
books
}
//保存图书，将图书写入文件
def saveBooks(books: ListBuffer[BookModel]): Unit = {
val writer = new java.io.PrintWriter(new java.io.File("books.txt"))
for(book <- books){
writer.println(book.id + "," + book.name + "," + book.author + "," + book.available)
}
writer.close()
}
}

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package org.app
package dao
import models.BorrowRecordModel
import scala.collection.mutable.ListBuffer
import scala.io.Source
class BorrowRecordDAO {
// 读出借阅记录
def loadBorrowRecords(): ListBuffer[BorrowRecordModel] = {
val borrowRecords = ListBuffer[BorrowRecordModel]()
val lines = Source.fromFile("borrow_records.txt")
for (line <- lines.getLines()) {
val parts = line.split(",")
borrowRecords += BorrowRecordModel(
parts(0),
parts(1).toInt,
parts(2),
parts(3),
if(parts.length>4) Some(parts(4)) else None
)
}
borrowRecords
}
// 写入借阅记录
def saveBorrowRecords(records: ListBuffer[BorrowRecordModel]): Unit = {
val writer = new java.io.PrintWriter("borrow_records.txt")
for (record <- records) {
writer.println(record.userName + "," + record.bookID + "," + record.bookName + "," + record.borrowDate + "," + record.returnDate.getOrElse(""))
}
writer.close()
}
}

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package org.app
package dao
import models.UserModel
import scala.collection.mutable.ListBuffer
class UserDAO {
//加载所有的用户
def loadUsers(): ListBuffer[UserModel] = {
val users = new ListBuffer[UserModel]()
val source = scala.io.Source.fromFile("users.txt")
for (line <- source.getLines()) {
val Array(username,password,role) = line.split(",")
//实例化一本书，保存到List
users += UserModel(username,password,role)
}
//关闭连接
source.close()
users
}
//保存用户，将用户列表写入文件
def saveUsers(users: ListBuffer[UserModel]): Unit = {
val writer = new java.io.PrintWriter(new java.io.File("users.txt"))
for (user <- users) {
writer.println(user.username + "," + user.password + "," + user.role)
}
writer.close()
}
}

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package org.app
package models
//借阅记录类
case class BorrowRecordModel (
userName:String, // 借书人
bookID:Int, // 书ID
bookName:String, // 书名
borrowDate:String, // 借书日期
var returnDate:Option[String] = None // 归还日期
)

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package org.app
package models
case class UserModel(
username:String,
password:String,
role:String //普通用户，管理员
) {
}

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package org.app
package service
import models.{BookModel, BorrowRecordModel}
import org.app.dao.{BookDAO, BorrowRecordDAO}
import java.time.LocalDateTime
import scala.collection.mutable.ListBuffer
class BookService {
private val bookDAO = new BookDAO()
private val borrowRecordDAO = new BorrowRecordDAO()
//查询所有的图书
// def searchBooks(query:String): 图书列表List(Book对象)
def searchBooks(query: String): ListBuffer[BookModel] = {
//从文本文件中读取书本信息，并保存列表中，返回
val books = bookDAO.loadBooks()
query match {
case "" => books //没有条件，就返回全部
case _ => books.filter(b => b.name.contains(query) || b.author.contains(query)) //有条件，就过滤
}
}
// 普通用户. 借阅图书
def borrowBook(username: String, bookId: Int): Boolean = {
// (1)根据图书的ID. 查询图书. 判断图书是否存在
val books = bookDAO.loadBooks()
// 所有的借阅记录
val records = borrowRecordDAO.loadBorrowRecords()
val book = books.find(b => b.id == bookId)
if (book.nonEmpty) {
val b = book.get
// (2)判断图书是否已经被借出
if (b.available) {
// (3)借阅图书更新这本书的状态
b.available = false
//把更新之后的图书的信息写回txt文件
bookDAO.saveBooks(books)
//添加一条借阅记录
records += BorrowRecordModel(username, b.id, b.name, LocalDateTime.now().toString)
//写借阅记录回文件
borrowRecordDAO.saveBorrowRecords(records)
println("借阅成功.已保存借阅记录！")
true
} else {
println("这本书被借走了")
false
}
} else {
println("没有找到这本书")
false
}
}
// 普通用户，查询自己的借阅记录
def queryBorrowedBooks(username: String): ListBuffer[BorrowRecordModel] = {
// 1.把所有的记录全部读出来
val records = borrowRecordDAO.loadBorrowRecords()
// 2.过滤出当前用户的借阅记录
records.filter(r => r.userName == username)
}
// 普通用户.归还自己借的某一本书
def returnBook(username: String, bookId: Int): Boolean = {
// 1.确定这本书是他本人借的并处于没有归还的状态
queryBorrowedBooks(username).find(r => r.bookID == bookId && r.returnDate.isEmpty) match {
case Some(record) =>
// 2.更新书的状态
// 2.1 加载全部的书
val books = bookDAO.loadBooks()
// 2.2 选择当前这本书
val b = books.find(_.id == bookId).get
b.available = true
// 2.3 把更新之后的状态写回.txt文件
bookDAO.saveBooks(books)
// 3.更新借阅记录的状态
// 3.1 加载全部的借阅记录
val records = borrowRecordDAO.loadBorrowRecords()
// 3.2 找到当前这本书的借阅记录 bookID,userName,returnDate = None
val r = records.find(r => r.bookID == bookId && r.userName == username && r.returnDate.isEmpty).get
r.returnDate = Some(LocalDateTime.now().toString)
// 3.3 把更新之后的状态写回.txt文件
borrowRecordDAO.saveBorrowRecords(records)
true
case None => false
}
}
// 添加图书
def addBook(book: BookModel): Unit = {
// 1. 生成一个book ID
// 查询所有图书. 找到最大的ID,+1
var id = 1
val books = bookDAO.loadBooks()
if(books.nonEmpty){
id = books.map(_.id).max + 1
}
// 2. 更新ID
val newBook = book.copy(id = id)
// 3. 把新的图书添加到books
books += newBook
// 4.写回到.txt中
bookDAO.saveBooks(books)
}
}