柚子快報(bào)邀請(qǐng)碼778899分享：java 圖書(shū)管理系統(tǒng)

http://yzkb.51969.com/

前言

這次文章將帶大家實(shí)現(xiàn)一個(gè)圖書(shū)管理系統(tǒng)，界面如下：

找到對(duì)象

我們從上面就可以知道，我們需要?jiǎng)?chuàng)建兩個(gè)對(duì)象，一個(gè)是管理員對(duì)象，一個(gè)是普通用戶對(duì)象，由于這兩個(gè)對(duì)象都是用戶這一范疇，所以我們可以為他們創(chuàng)建一個(gè)父類，那我們可以將這三個(gè)類放在同一個(gè)包上，如下圖所示：

然后我們進(jìn)一步思考我們還需要什么類，由于這是一個(gè)圖書(shū)管理系統(tǒng)，所以我們可以創(chuàng)建書(shū)這個(gè)類用來(lái)創(chuàng)建多本的書(shū)，我們還可以創(chuàng)建一個(gè)書(shū)架用來(lái)存放書(shū)籍，這兩個(gè)類我們把他們放在同一個(gè)包上：

我們有很多個(gè)功能需要實(shí)現(xiàn)，例如增加圖書(shū)，刪除圖書(shū)，查詢圖書(shū)等等…我們可以再創(chuàng)建一個(gè)包用來(lái)專門存放這些功能：

最后我們需要?jiǎng)?chuàng)建一個(gè)Main類用來(lái)組裝上面的代碼，使其成為一個(gè)管理系統(tǒng)。

代碼實(shí)現(xiàn)

book包

Book類

這里的書(shū)包括書(shū)名，作者，書(shū)的類型，價(jià)格以及書(shū)是否被借出的狀態(tài)，這樣我們可以創(chuàng)建對(duì)應(yīng)的成員變量，為了有封裝的體現(xiàn)，我們可以使用private修飾這些創(chuàng)元變量，然后通過(guò)Getter and Setter 來(lái)實(shí)現(xiàn)成員變量的訪問(wèn)就可以了.

由于我們會(huì)訪問(wèn)這本書(shū)的所有信息，我們就需要打印，這時(shí)候我們就要重寫(xiě)toString 方法，盡管IDEA編譯器會(huì)自動(dòng)幫我們實(shí)現(xiàn)，但是對(duì)于書(shū)是否被借出的狀態(tài)打印，我們需要打印字符串（“未借閱” 和 “已借閱”）這兩種狀態(tài)，但是這個(gè)成員變量是boolean類型的，所以我們?nèi)绻蝗バ薷膖oString 方法的話，我們就會(huì)得到false和true這兩種打印形式，那么我們就要稍微修改一下代碼，這時(shí)候我們可以使用三目表達(dá)式來(lái)進(jìn)行修改

如果直接使用編譯器自動(dòng)生成 toString 代碼：

public Book(String name, String author, String type, double price, boolean is_borrowed) {

this.name = name;

this.author = author;

this.type = type;

this.price = price;

this.is_borrowed = is_borrowed;

}

結(jié)合上述的要點(diǎn)，我們可以得到下面的代碼：

public class Book {

private String name;

private String author;

private String type;

private double price;

private boolean is_borrowed;

@Override

public String toString() {

return "Book{" +

"name='" + name + '\'' +

", author='" + author + '\'' +

", type='" + type + '\'' +

", price=" + price +

(is_borrowed == false ? " 未借閱": " 已借閱") +

'}';

}

public Book(String name, String author, String type, double price) {

this.name = name;

this.author = author;

this.type = type;

this.price = price;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getAuthor() {

return author;

}

public void setAuthor(String author) {

this.author = author;

}

public String getType() {

return type;

}

public void setType(String type) {

this.type = type;

}

public double getPrice() {

return price;

}

public void setPrice(double price) {

this.price = price;

}

public boolean isIs_borrowed() {

return is_borrowed;

}

public void setIs_borrowed(boolean is_borrowed) {

this.is_borrowed = is_borrowed;

}

}

BookList 類 （書(shū)架）

我們可以使用組合來(lái)將書(shū)放在代碼里，我們還可以先將三本書(shū)放在書(shū)架上，這時(shí)候我們可以通過(guò)構(gòu)造方法來(lái)初始化書(shū)架，我們還需要知道書(shū)架上目前有多少本書(shū)，容量是多少，成員變量要相應(yīng)的寫(xiě)上去，并且通過(guò)getter和setter方法來(lái)來(lái)實(shí)現(xiàn)成員變量的訪問(wèn)…

public class BookList {

private Book[] books;

private int curSize;

private int count;

public BookList(){

books = new Book[10];

books[0] = new Book("三國(guó)演義","羅貫中","名著",30.12);

books[1] = new Book("西游記","吳承恩","名著",30.14);

books[2] = new Book("紅樓夢(mèng)","曹雪芹","名著",50.42);

curSize = 3;

count = 10;

}

public int getCurSize() {

return curSize;

}

public void setCurSize(int curSize) {

this.curSize = curSize;

}

public int getCount() {

return count;

}

public void setCount(int count) {

this.count = count;

}

public Book getBooks(int i) {

return books[i];

}

public void setBooks(int pos,Book newBook) {

books[pos] = newBook;

}

}

user包

我們先來(lái)創(chuàng)建父類 User，需要姓名這一個(gè)成員變量，由于父類本身是要被繼承的，所以我們可以將其實(shí)現(xiàn)為抽象類，不同的身份有不同的菜單列表，既然都是菜單我們不妨在父類寫(xiě)一個(gè)抽象方法，提醒子類要記得寫(xiě)菜單，還有用戶會(huì)輸入不同的數(shù)字來(lái)實(shí)現(xiàn)不同的功能，這里我們可以創(chuàng)建一個(gè)功能實(shí)現(xiàn)的方法，這樣子我們就可以通過(guò)父類的引用來(lái)實(shí)現(xiàn)不同的子類所對(duì)應(yīng)的功能…

public abstract class User {

public String name;

protected Ioperate[] opertions;

public User(String name) {

this.name = name;

}

public abstract int menu();

public void work(int choice, BookList bookList){

opertions[choice].operate(bookList);

}

}

管理者

public class Manager extends User{

public Manager(String name) {

super(name);

opertions = new Ioperate[] {

new Exit(),

new Find(),

new Add(),

new Delete(),

new Show()

};

}

@Override

public int menu() {

System.out.println("*******管理員菜單*******");

System.out.println(" 1.查詢圖書(shū)");

System.out.println(" 2.增加圖書(shū)");

System.out.println(" 3.刪除圖書(shū)");

System.out.println(" 4.顯示所有圖書(shū)");

System.out.println(" 0.退出系統(tǒng)");

System.out.println("************************");

System.out.println("請(qǐng)輸入你的選擇：");

Scanner scan = new Scanner(System.in);

int choice = scan.nextInt();

return choice;

}

}

普通用戶

public class DomesticConsumer extends User {

public DomesticConsumer(String name) {

super(name);

opertions = new Ioperate[] {

new Exit(),

new Find(),

new Borrow(),

new Return()

};

}

@Override

public int menu() {

System.out.println("*******普通用戶菜單*******");

System.out.println(" 1.查詢圖書(shū)");

System.out.println(" 2.借閱圖書(shū)");

System.out.println(" 3.歸還圖書(shū)");

System.out.println(" 0.退出系統(tǒng)");

System.out.println("************************");

System.out.println("請(qǐng)輸入你的選擇：");

Scanner scan = new Scanner(System.in);

int choice = scan.nextInt();

return choice;

}

}

Ioperation包

接口

我們可以通過(guò)一個(gè)接口來(lái)實(shí)現(xiàn)功能的有機(jī)聯(lián)系，這樣我們就可以通過(guò)這個(gè)接口類型來(lái)實(shí)現(xiàn)不同的方法，我們知道這些方法幾乎都會(huì)操作書(shū)架，所以我們將書(shū)架作為參數(shù)進(jìn)行傳遞就可以了。

public interface Ioperate {

void operate(BookList bookList);

}

Add

我們直接采用尾插，我們需要判斷一下書(shū)架是否還能繼續(xù)放書(shū)，需要將目前的圖書(shū)數(shù)目和書(shū)架容量進(jìn)行比較就可以了，接下來(lái)就是創(chuàng)建新書(shū)，將新書(shū)放到書(shū)架即可，這時(shí)候我們要注意書(shū)架放書(shū)的代碼是否正確，我們使用IDEA編譯器只能實(shí)現(xiàn)Book[]類型的getter和setter，但是書(shū)的類型是Book，所以我們需要自己寫(xiě)一個(gè)放書(shū)的代碼:

public void setBooks(int pos,Book newBook) {

books[pos] = newBook;

}

為什么不直接寫(xiě)books[curSize] = newBook呢？

因?yàn)槲覀兒竺鎰h除圖書(shū)的代碼里也是需要對(duì)書(shū)架上的書(shū)進(jìn)行移動(dòng)，會(huì)用到setter方法，所以為了代碼的通用性高，我們就多加了一個(gè)pos參數(shù)

public class Add implements Ioperate{

@Override

public void operate(BookList bookList) {

int count = bookList.getCount();

int curSize = bookList.getCurSize();

if(count == curSize){

System.out.println("書(shū)架已滿，無(wú)法再放入別的圖書(shū).......");

return;

}

System.out.println("請(qǐng)輸入你要增加的書(shū)名:");

Scanner scan = new Scanner(System.in);

String name = scan.nextLine();

System.out.println("請(qǐng)輸入作者名字");

String author = scan.nextLine();

System.out.println("請(qǐng)輸入圖書(shū)類型：");

String type = scan.nextLine();

System.out.println("請(qǐng)輸入圖書(shū)價(jià)格：");

double price = scan.nextDouble();

Book newBook = new Book(name,author,type,price);

bookList.setBooks(curSize,newBook);

bookList.setCurSize(curSize + 1);

}

}

在進(jìn)行刪除圖書(shū)，查詢圖書(shū)，這里我采用的是通過(guò)書(shū)名進(jìn)行遍歷訪問(wèn)的方式。 這時(shí)候我們就要小心，因?yàn)槲覀兪菍?duì)書(shū)架進(jìn)行操控的，所以我們要先拿到書(shū)這個(gè)對(duì)象，那我們就要看怎么拿出對(duì)應(yīng)的書(shū)，由于編譯器只能實(shí)現(xiàn)Book[]類型的getter，所以我們還是要自己寫(xiě)一個(gè)拿書(shū)的代碼。 由于書(shū)名是String類型，所以可以使用equals方法經(jīng)行字符串的比對(duì)。所以我們拿到書(shū)后還要訪問(wèn)書(shū)的書(shū)名再進(jìn)行比對(duì)即可。

public Book getBooks(int i) {

return books[i];

}

Book book = bookList.getBooks(i);

if(book.getName().equals(name)){

//......

}

Delete

刪除書(shū)也很容易，我們需要把待刪除的書(shū)后面的書(shū)進(jìn)行前移

public class Delete implements Ioperate{

@Override

public void operate(BookList bookList) {

int curSize = bookList.getCurSize();

if(curSize == 0){

System.out.println("書(shū)架已空，無(wú)法繼續(xù)刪除......");

}

System.out.println("請(qǐng)輸入你要?jiǎng)h除圖書(shū)的書(shū)名：");

Scanner scan = new Scanner(System.in);

String name = scan.nextLine();

for (int i = 0; i < curSize; i++) {

Book book = bookList.getBooks(i);

if(book.getName().equals(name)){

System.out.println("刪除成功......");

for (int j = i; j < curSize - 1; j++) {

bookList.setBooks(j,bookList.getBooks(j+1));

}

bookList.setCurSize(curSize - 1);

return;

}

}

System.out.println("未查詢到該書(shū).....");

}

}

Borrow

public class Borrow implements Ioperate{

@Override

public void operate(BookList bookList) {

System.out.println("請(qǐng)輸入你要借閱圖書(shū)書(shū)名：");

Scanner scan = new Scanner(System.in);

String name = scan.nextLine();

int curSize = bookList.getCurSize();

for (int i = 0; i < curSize; i++) {

Book book = bookList.getBooks(i);

if(book.getName().equals(name)){

if(book.isIs_borrowed() == false){

System.out.println("該書(shū)已被你成功借閱......");

book.setIs_borrowed(true);

}else{

System.out.println("該書(shū)已被借閱，無(wú)法被再次借閱.....");

}

return;

}

}

System.out.println("未查詢到此書(shū)......");

}

}

Find

public class Find implements Ioperate{

@Override

public void operate(BookList bookList) {

System.out.println("輸入你要查詢的書(shū)名：");

Scanner scan = new Scanner(System.in);

String name = scan.nextLine();

int count = bookList.getCurSize();

for (int i = 0; i < count; i++) {

Book book = bookList.getBooks(i);

if(book.getName().equals(name)){

System.out.println(book);

return;

}

}

System.out.println("未查詢到此書(shū)......");

}

}

Return

public class Return implements Ioperate{

@Override

public void operate(BookList bookList) {

System.out.println("請(qǐng)輸入你要?dú)w還書(shū)名：");

Scanner scan = new Scanner(System.in);

String name = scan.nextLine();

int count = bookList.getCurSize();

for (int i = 0; i < count; i++) {

Book book = bookList.getBooks(i);

if(book.getName().equals(name)){

if(book.isIs_borrowed() == true){

System.out.println("歸還成功......");

book.setIs_borrowed(false);

}else{

System.out.println("該圖書(shū)已被歸還到書(shū)架上，無(wú)需重復(fù)歸還......");

}

return;

}

}

System.out.println("未查詢到該圖書(shū).....");

}

}

Show

public class Show implements Ioperate{

@Override

public void operate(BookList bookList) {

int count = bookList.getCurSize();

for (int i = 0; i < count; i++) {

System.out.println(bookList.getBooks(i));

}

}

}

Exit

退出程序的代碼就是System.exit(數(shù)字)，數(shù)字零表示正常退出的意思。

public class Exit implements Ioperate{

@Override

public void operate(BookList bookList) {

System.out.println("退出系統(tǒng)......");

System.exit(0);

}

}

登錄

我們?cè)費(fèi)ain類寫(xiě)一個(gè)login方法

public static User login(){

Scanner scan = new Scanner(System.in);

System.out.println("請(qǐng)輸入你的姓名：");

String name = scan.nextLine();

System.out.println("1.管理員 2.普通用戶");

System.out.println("請(qǐng)輸入你的身份：");

int identity = scan.nextInt();

if(identity == 1){

return new Manager(name);

}else{

return new DomesticConsumer(name);

}

}

主邏輯實(shí)現(xiàn)

我們先登錄，然后創(chuàng)建書(shū)架，接著打印菜單，用戶輸入指令，計(jì)算機(jī)進(jìn)行對(duì)應(yīng)的操作：

public static void main(String[] args) {

//創(chuàng)建書(shū)架

BookList bookList = new BookList();

//login

User user = login();

while(true){

//功能菜單選擇

int choice = user.menu();

//功能實(shí)現(xiàn)

user.work(choice,bookList);

}

}

最終代碼

Main類

import book.BookList;

import user.DomesticConsumer;

import user.Manager;

import user.User;

import java.util.Scanner;

public class Main {

public static User login(){

Scanner scan = new Scanner(System.in);

System.out.println("請(qǐng)輸入你的姓名：");

String name = scan.nextLine();

System.out.println("1.管理員 2.普通用戶");

System.out.println("請(qǐng)輸入你的身份：");

int identity = scan.nextInt();

if(identity == 1){

return new Manager(name);

}else{

return new DomesticConsumer(name);

}

}

public static void main(String[] args) {

//創(chuàng)建書(shū)架

BookList bookList = new BookList();

//login

User user = login();

while(true){

//功能菜單選擇

int choice = user.menu();

//功能實(shí)現(xiàn)

user.work(choice,bookList);

}

}

}

user包

User

package user;

import Ioperation.Ioperate;

import book.BookList;

public abstract class User {

public String name;

protected Ioperate[] opertions;

public User(String name) {

this.name = name;

}

public abstract int menu();

public void work(int choice, BookList bookList){

opertions[choice].operate(bookList);

}

}

Manager

package user;

import Ioperation.*;

import java.util.Scanner;

public class Manager extends User{

public Manager(String name) {

super(name);

opertions = new Ioperate[] {

new Exit(),

new Find(),

new Add(),

new Delete(),

new Show()

};

}

@Override

public int menu() {

System.out.println("*******管理員菜單*******");

System.out.println(" 1.查詢圖書(shū)");

System.out.println(" 2.增加圖書(shū)");

System.out.println(" 3.刪除圖書(shū)");

System.out.println(" 4.顯示所有圖書(shū)");

System.out.println(" 0.退出系統(tǒng)");

System.out.println("************************");

System.out.println("請(qǐng)輸入你的選擇：");

Scanner scan = new Scanner(System.in);

int choice = scan.nextInt();

return choice;

}

}

DomesticConsumer

package user;

import Ioperation.*;

import java.util.Scanner;

public class DomesticConsumer extends User {

public DomesticConsumer(String name) {

super(name);

opertions = new Ioperate[] {

new Exit(),

new Find(),

new Borrow(),

new Return()

};

}

@Override

public int menu() {

System.out.println("*******普通用戶菜單*******");

System.out.println(" 1.查詢圖書(shū)");

System.out.println(" 2.借閱圖書(shū)");

System.out.println(" 3.歸還圖書(shū)");

System.out.println(" 0.退出系統(tǒng)");

System.out.println("************************");

System.out.println("請(qǐng)輸入你的選擇：");

Scanner scan = new Scanner(System.in);

int choice = scan.nextInt();

return choice;

}

}

book 包

Book

package book;

public class Book {

private String name;

private String author;

private String type;

private double price;

private boolean is_borrowed;

@Override

public String toString() {

return "Book{" +

"name='" + name + '\'' +

", author='" + author + '\'' +

", type='" + type + '\'' +

", price=" + price +

(is_borrowed == false ? " 未借閱": " 已借閱") +

'}';

}

public Book(String name, String author, String type, double price) {

this.name = name;

this.author = author;

this.type = type;

this.price = price;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getAuthor() {

return author;

}

public void setAuthor(String author) {

this.author = author;

}

public String getType() {

return type;

}

public void setType(String type) {

this.type = type;

}

public double getPrice() {

return price;

}

public void setPrice(double price) {

this.price = price;

}

public boolean isIs_borrowed() {

return is_borrowed;

}

public void setIs_borrowed(boolean is_borrowed) {

this.is_borrowed = is_borrowed;

}

}

BookList

package book;

public class BookList {

private Book[] books;

private int curSize;

private int count;

public BookList(){

books = new Book[10];

books[0] = new Book("三國(guó)演義","羅貫中","名著",30.12);

books[1] = new Book("西游記","吳承恩","名著",30.14);

books[2] = new Book("紅樓夢(mèng)","曹雪芹","名著",50.42);

curSize = 3;

count = 10;

}

public int getCurSize() {

return curSize;

}

public void setCurSize(int curSize) {

this.curSize = curSize;

}

public int getCount() {

return count;

}

public void setCount(int count) {

this.count = count;

}

public Book getBooks(int i) {

return books[i];

}

public void setBooks(int pos,Book newBook) {

books[pos] = newBook;

}

}

Ioperation包

Ioperate

package Ioperation;

import book.BookList;

public interface Ioperate {

void operate(BookList bookList);

}

Add

package Ioperation;

import book.Book;

import book.BookList;

import java.util.Scanner;

public class Add implements Ioperate{

@Override

public void operate(BookList bookList) {

int count = bookList.getCount();

int curSize = bookList.getCurSize();

if(count == curSize){

System.out.println("書(shū)架已滿，無(wú)法再放入別的圖書(shū).......");

return;

}

System.out.println("請(qǐng)輸入你要增加的書(shū)名:");

Scanner scan = new Scanner(System.in);

String name = scan.nextLine();

System.out.println("請(qǐng)輸入作者名字");

String author = scan.nextLine();

System.out.println("請(qǐng)輸入圖書(shū)類型：");

String type = scan.nextLine();

System.out.println("請(qǐng)輸入圖書(shū)價(jià)格：");

double price = scan.nextDouble();

Book newBook = new Book(name,author,type,price);

bookList.setBooks(curSize,newBook);

bookList.setCurSize(curSize + 1);

}

}

Borrow

package Ioperation;

import book.Book;

import book.BookList;

import java.util.Scanner;

public class Borrow implements Ioperate{

@Override

public void operate(BookList bookList) {

System.out.println("請(qǐng)輸入你要借閱圖書(shū)書(shū)名：");

Scanner scan = new Scanner(System.in);

String name = scan.nextLine();

int curSize = bookList.getCurSize();

for (int i = 0; i < curSize; i++) {

Book book = bookList.getBooks(i);

if(book.getName().equals(name)){

if(book.isIs_borrowed() == false){

System.out.println("該書(shū)已被你成功借閱......");

book.setIs_borrowed(true);

}else{

System.out.println("該書(shū)已被借閱，無(wú)法被再次借閱.....");

}

return;

}

}

System.out.println("未查詢到此書(shū)......");

}

}

Delete

package Ioperation;

import book.Book;

import book.BookList;

import java.util.Scanner;

public class Delete implements Ioperate{

@Override

public void operate(BookList bookList) {

int curSize = bookList.getCurSize();

if(curSize == 0){

System.out.println("書(shū)架已空，無(wú)法繼續(xù)刪除......");

}

System.out.println("請(qǐng)輸入你要?jiǎng)h除圖書(shū)的書(shū)名：");

Scanner scan = new Scanner(System.in);

String name = scan.nextLine();

for (int i = 0; i < curSize; i++) {

Book book = bookList.getBooks(i);

if(book.getName().equals(name)){

System.out.println("刪除成功......");

for (int j = i; j < curSize - 1; j++) {

bookList.setBooks(j,bookList.getBooks(j+1));

}

bookList.setCurSize(curSize - 1);

return;

}

}

System.out.println("未查詢到該書(shū).....");

}

}

Exit

package Ioperation;

import book.BookList;

public class Exit implements Ioperate{

@Override

public void operate(BookList bookList) {

System.out.println("退出系統(tǒng)......");

System.exit(0);

}

}

Find

package Ioperation;

import book.Book;

import book.BookList;

import java.util.Scanner;

public class Find implements Ioperate{

@Override

public void operate(BookList bookList) {

System.out.println("輸入你要查詢的書(shū)名：");

Scanner scan = new Scanner(System.in);

String name = scan.nextLine();

int count = bookList.getCurSize();

for (int i = 0; i < count; i++) {

Book book = bookList.getBooks(i);

if(book.getName().equals(name)){

System.out.println(book);

return;

}

}

System.out.println("未查詢到此書(shū)......");

}

}

Return

package Ioperation;

import book.Book;

import book.BookList;

import java.util.Scanner;

public class Return implements Ioperate{

@Override

public void operate(BookList bookList) {

System.out.println("請(qǐng)輸入你要?dú)w還書(shū)名：");

Scanner scan = new Scanner(System.in);

String name = scan.nextLine();

int count = bookList.getCurSize();

for (int i = 0; i < count; i++) {

Book book = bookList.getBooks(i);

if(book.getName().equals(name)){

if(book.isIs_borrowed() == true){

System.out.println("歸還成功......");

book.setIs_borrowed(false);

}else{

System.out.println("該圖書(shū)已被歸還到書(shū)架上，無(wú)需重復(fù)歸還......");

}

return;

}

}

System.out.println("未查詢到該圖書(shū).....");

}

}

Show

package Ioperation;

import book.BookList;

public class Show implements Ioperate{

@Override

public void operate(BookList bookList) {

int count = bookList.getCurSize();

for (int i = 0; i < count; i++) {

System.out.println(bookList.getBooks(i));

}

}

}

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http://yzkb.51969.com/

參考閱讀