圖書館管理系統，這個小程序是Java基礎的應用，比較簡單，沒有用到太難的東西。同時，受於技術所限，未能連接到數據庫。等以後學了，看有機會再加上，現在就這樣吧。
代碼：
User類
package com.Library;
public class User {
public String username="張三";
public int password=123456;
}
Book類
package com.Library;
public class Book {
int id;
String name;
int State;
public String ToString(){
String BookState="";
if(this.State==1)
{
BookState="未借閱";
}
else{
BookState="已借閱";
}
return this.id+"\t"+this.name+"\t\t"+BookState;
}
}
BookData類
package com.Library;
public class BookData {
Book[] books=new Book[50];
public Book[] AllBook(){
Book book1=new Book();
book1.id=1;
book1.name="Java基礎";
book1.State=1;
books[0]=book1;
Book book2=new Book();
book2.id=2;
book2.name="Html基礎";
book2.State=1;
books[1]=book2;
Book book3=new Book();
book3.id=3;
book3.name="Matlab基礎";
book3.State=1;
books[2]=book3;
Book book4=new Book();
book4.id=4;
book4.name="Lingo基礎";
book4.State=1;
books[3]=book4;
Book book5=new Book();
book5.id=5;
book5.name="Spss基礎";
book5.State=2;
books[4]=book5;
return books;
}
}
Menu類
package com.Library;
import java.util.Scanner;
public class Menu {
Scanner input= new Scanner(System.in);
User u=new User();
BookData bookdata=new BookData();
Book[] bs=new Book[50];
public void leading(){
bs=bookdata.AllBook();
}
public void StartMenu(){
System.out.println("*****************************************\t\n");
System.out.println("歡迎進入網上圖書館\t\n");
System.out.println("1.登錄\t\n");
System.out.println("2.離開\t\n");
System.out.println("*****************************************\t\n");
int choice1=input.nextInt();
switch(choice1){
case 1:
this.Login();
break;
case 2:
System.exit(0);
break;
default:
this.StartMenu();
break;
}
}
public void Login(){
System.out.println("*****************************************\t\n");
System.out.println("輸入信息\t\n");
System.out.println("用戶名：\t\n");
String Busername=input.next();
System.out.println("密碼：\t\n");
int Bpassword=input.nextInt();
int Count=3;
boolean flag=true;
do{
if (Busername.equals(u.username) && Bpassword==u.password)
{
System.out.println("登錄成功\t\n");
this.NextMenu();
flag=false;
}
else{
Count--;
if(Count==0)
{
System.out.println("登錄失敗，次數已用完，請5分鐘後再試\n");
}
else{
System.out.println("登錄失敗，還有"+Count+"次\n");
this.Login();
}
}
}while(flag);
}
public void NextMenu(){
System.out.println("*****************************************\t\n");
System.out.println("1.圖書目錄\t\n");
System.out.println("2.借閱圖書\t\n");
System.out.println("3.歸還圖書\t\n");
System.out.println("4.查找圖書\t\n");
System.out.println("5.添加圖書\t\n");
System.out.println("6.借閱情況\t\n");
System.out.println("7.刪除圖書\t\n");
System.out.println("8.修改圖書\t\n");
System.out.println("9.退出\t\n");
System.out.println("*****************************************\t\n");
int choice2=input.nextInt();
switch (choice2) {
case 1:
this.BookMenu();
break;
case 2:
this.BrowserBook();
break;
case 3:
this.BackBook();
break;
case 4:
this.FindBook();
break;
case 5:
this.AddBook();
break;
case 6:
this.finddetail();
break;
case 7:
this.DeleteBook();
break;
case 8:
this.UpdataBook();
break;
case 9:
System.out.println("謝謝使用，再見");
System.exit(0);
break;
default:
break;
}
}
// 1
public void BookMenu(){
System.out.println("編號\t\t"+"書名\t"+"借閱信息\t\t");
for(int i=0;i<bs.length;i++){
if(bs[i]!=null){
System.out.println(bs[i].ToString());
}
}
returnMenu();
}
// T1
public void returnMenu(){
System.out.println("輸入$返回上一級");
String a=input.next();
if (a.equals("$")){
this.NextMenu();
}
else{
System.out.println("輸入錯誤，請重新輸入");
returnMenu();
}
}
//2
int index=0;
Book[] Browser=new Book[50];
public void BrowserBook(){
System.out.println("請選擇借閱方式：\t\n");
System.out.println("1.按編號借閱\t\n");
System.out.println("2.按書名借閱\t\n");
int choice2 = input.nextInt();
switch (choice2) {
case 1:
BrowserId();
break;
case 2:
BrowserName();
break;
default:
System.out.println("輸入錯誤，請重新輸入");
BrowserBook();
break;
}
}
//2-1
public void BrowserId(){
System.out.println("請輸出圖書編號：");
int id=input.nextInt();
boolean flag=true;
for(int i=0;i<bs.length;i++){
if(bs[i]!=null){
if(bs[i].id==id){
if(bs[i].State==1){
System.out.println("借閱成功");
bs[i].State=0;
Browser[index++]=bs[i];
flag=false;
break;
}
else{
System.out.println("此書已借閱！");
flag=false;
break;
}
}
}
}
if(flag){
System.out.println("書庫內無此書！");
}
returnMenu();
}
//2-2
public void BrowserName(){
System.out.println("請輸出圖書名字：");
String name=input.next();
boolean flag=true;
for(int i=0;i<bs.length;i++){
if(bs[i]!=null){
if(bs[i].name==name){
if(bs[i].State==1){
System.out.println("借閱成功");
bs[i].State=0;
flag=false;
break;
}
else{
System.out.println("此書已借閱！");
flag=false;
break;
}
}
}
}
if(flag){
System.out.println("書庫內無此書！");
returnMenu();
}
}
//3
public void BackBook(){
System.out.println("輸入還書方式\n\t"+"1.輸入所還圖書名稱\t"+"2.輸入所還圖書編號\t\n");
int a=input.nextInt();
switch (a) {
case 1:
BackName();
break;
case 2:
BackId();
break;
default:
System.out.println("輸入錯誤，請重新輸入：");
BackBook();
break;
}
}
//3-1
public void BackName(){
System.out.println("請輸入所還圖書名稱：");
String bookname=input.next();
boolean flag=true;
for (int i = 0; i < bs.length; i++) {
if (bs[i]!=null) {
if (bs[i].State!=1) {
if (bookname.equals(bs[i].name)) {
System.out.println("歸還成功");
bs[i].State=1;
for (int j = 0; j < Browser.length; j++) {
if(Browser[j]!=null){
if (Browser[j]==bs[i]) {
Browser[j]=null;
flag=false;
break;
}
}
}
}
}
}
}
if (flag) {
System.out.println("操作失敗！");
BackName();
}
returnMenu();
}
//3-2
public void BackId(){
System.out.println("請輸入所還圖書編號：");
int bookid=input.nextInt();
boolean flag=true;
for (int i = 0; i < bs.length; i++) {
if (bs[i]!=null) {
if (bs[i].State!=1) {
if (bookid==bs[i].id) {
System.out.println("歸還成功");
bs[i].State=1;
for (int j = 0; j < Browser.length; j++) {
if(Browser[j]!=null){
if (Browser[j]==bs[i]) {
Browser[j]=null;
flag=false;
break;
}
}
}
}
}
}
}
if (flag) {
System.out.println("操作失敗！請重新操作");
BackId();
}
returnMenu();
}
//4
public void FindBook(){
System.out.println("輸入查詢方式\n\t"+"1.輸入查詢圖書名稱\t"+"2.輸入查詢圖書編號\t\n");
int a=input.nextInt();
switch (a) {
case 1:
FindName();
break;
case 2:
FindId();
break;
default:
System.out.println("輸入錯誤，請重新輸入：");
BackBook();
break;
}
}
//4-1
public void FindName(){
System.out.println("請輸入查詢圖書名稱：");
String bookname=input.next();
boolean flag=true;
for (int i = 0; i < bs.length; i++) {
if (bs[i]!=null) {
if (bookname.equals(bs[i].name)) {
System.out.println("編號\t\t"+"書名\t"+"借閱信息\t\t");
System.out.println(bs[i].ToString());
flag=false;
}
}
}
if(flag){
System.out.println("查無此書！請重新查找");
FindName();
}
}
//4-2
public void FindId(){
System.out.println("請輸入查詢圖書編號：");
int bookid=input.nextInt();
boolean flag=true;
for (int i = 0; i < bs.length; i++) {
if (bs[i]!=null) {
if (bookid==(bs[i].id)) {
System.out.println("編號\t\t"+"書名\t"+"借閱信息\t\t");
System.out.println(bs[i].ToString());
}
}
}
if(flag){
System.out.println("查無此書！請重新查找");
FindId();
}
}
//5
public void AddBook(){
Book book=new Book();
System.out.println("請輸入圖書名稱：");
String bookname=input.next();
System.out.println("請輸入圖書狀態：");
int bookstate=input.nextInt();
for (int i = 0; i < bs.length; i++) {
if (bs[i]==null) {
System.out.println("添加成功！");
book.name=bookname;
book.State=bookstate;
book.id=i+1;
bs[i]=book;
break;
}
}
returnMenu();
}
//6
public void finddetail(){
System.out.println("編號\t\t"+"書名\t"+"借閱信息\t\t");
boolean flag=true;
for(int i=0;i<Browser.length;i++){
if(Browser[i]!=null){
System.out.println(Browser[i].ToString());
flag=false;
}
}
if(flag){
System.out.println("無借閱記錄,請先借閱");
}
returnMenu();
}
//7
public void DeleteBook(){
System.out.println("輸入刪除編號：");
int newId=input.nextInt();
boolean flag=true;
for (int i = 0; i < bs.length; i++) {
if (bs[i]!=null) {
if (bs[i].id==newId) {
if (bs[i].State==1) {
System.out.println("操作成功，已刪除");
bs[i]=null;
flag=false;
break;
}
else {
System.out.println("此書已借出，不能刪除！\n請重新操作：");
flag=false;
DeleteBook();
}
}
}
}
if (flag) {
System.out.println("操作失敗，此書不存在，不能刪除！\n請重新操作：");
DeleteBook();
}
returnMenu();
}
//8
public void UpdataBook(){
System.out.println("輸入所修改書的編號：");
int Id=input.nextInt();
boolean flag=true;
for (int i = 0; i < bs.length; i++) {
if (bs[i]!=null) {
if(bs[i].id==Id){
System.out.println("編號\t\t"+"書名\t"+"借閱信息\t\t");
System.out.println(bs[i].ToString());
if (bs[i].State==1) {
System.out.println("請輸入新的書名：");
String name=input.next();
bs[i].name=name;
System.out.println("是否修改其他屬性（y/n）");
String s=input.next();
if (s.equals("y")) {
System.out.println("請輸入新的狀態：\n1.可借閱\t2.不可借閱\t");
int a=input.nextInt();
bs[i].State=a;
}
System.out.println("修改成功！");
flag=false;
break;
}
else {
System.out.println("此書已借出，禁止修改！");
flag=false;
break;
}
}
}
}
if (flag) {
System.out.println("此書不存在，禁止修改！請重新輸入：");
UpdataBook();
}
returnMenu();
}
}
MainMenu類
package com.Library;
public class MainMenu {
public static void main(String[] args){
Menu m=new Menu();
m.leading();
m.StartMenu();
}
}