Java 使用书本对象和成员对象创建库
我最近刚开始编程，遇到了一些小错误。我正在创建一个library对象，其中包含对book对象和member对象的引用，但是我在从member类访问方法并在library类中使用它们时遇到问题，而LibraryTester类中不会出现错误。这就是我写的代码 图书馆课Java 使用书本对象和成员对象创建库,java,Java,我最近刚开始编程，遇到了一些小错误。我正在创建一个library对象，其中包含对book对象和member对象的引用，但是我在从member类访问方法并在library类中使用它们时遇到问题，而LibraryTester类中不会出现错误。这就是我写的代码 图书馆课 package assignment; import java.nio.channels.MembershipKey; import java.util.ArrayList; import java.util.Scanner; i
package assignment;
import java.nio.channels.MembershipKey;
import java.util.ArrayList;
import java.util.Scanner;
import org.omg.Messaging.SyncScopeHelper;
public class Library {
// Declared an array list of type book
private ArrayList<Book> Books;
private MemberList members;;
public Library(ArrayList<Book> Books, Member member) {
this.Books = Books;
this.members=members;
};
public void displayBooks() {
System.out.println("\t\t\t-----The Current Books in the library are-----");
for (int i = 0; i < Books.size(); i++) {
System.out.println("\n" + "\t\t" + Books.get(i).getTitle() + "\t\t\t" + "\n\t\tAuthor: "
+ Books.get(i).getAuthor() + "\n\t\tThis Books ID is: " + Books.get(i).getBookID() + "\t\t\t\t\t\t"
+ "\n\t\tIs this book on loan? " + Books.get(i).getOnLoan() + "\t\t\t\t\t"
+ "\n\t\tThe number of times which this book has been loaned: " + Books.get(i).getNumOfLoans()
+ "\t\t");
}
}
// method to remove permanently a book object
public void removeBook() // the parameter that is passed through
// is the book id of the book that is to
// be removed
{
Scanner input = new Scanner(System.in);
int bookID = 0;
boolean successful = false;
try {
do {
System.out.println("Please enter the book ID of the book you wish to delete");
bookID = input.nextInt();
for (int i = 0; i < Books.size(); i++) {
if (bookID == Books.get(i).getBookID())
{
System.out.println("The Book " + Books.get(i).getTitle() + " was removed");
Books.remove(i);
successful = true;
break;
}
}
if (!successful) {
System.out.println("Book ID " + bookID + " does not exist");
}
} while (successful == false);
} catch (Exception e) {
System.out.println("ERROR: Invalid input" + "\nYou have been returned to the main menu");
}
}
public void editBook() {
boolean successful = false;
try {
do {
Scanner sc = new Scanner(System.in);
System.out.println("Please enter the book ID of the book who's details you wish to change");
int bookID = sc.nextInt();
sc.nextLine();
for (int i = 0; i < Books.size(); i++) {
if (Books.get(i).getBookID() == bookID) {
System.out.println("Please enter the new name of the book:");
String newTitle = sc.nextLine();
Books.get(i).setTitle(newTitle);
System.out.println("Please enter the name of the author of the book:");
String newAuthor = sc.nextLine();
Books.get(i).setAuthor(newAuthor);
System.out.println("Change of book details successful" + "\nNew book title: " + newTitle
+ "\nNew author: " + newAuthor);
successful = true;
}
}
if (!successful) {
System.out.println("This book does not exist ");
}
} while (successful == false);
} catch (Exception e) {
System.out.println("ERROR: Invalid input" + "\nYou have been returned to the main menu");
}
}
public void addBook() {
boolean successful = false;
int bookID = 0;
String title = "";
String author = "";
Scanner input = new Scanner(System.in);
do {
System.out.println("Please assign a 3 digit number for the books ID ");
bookID = input.nextInt();
input.nextLine();
if(bookID > 99 && bookID <1000){
for (int i = 0; i < Books.size(); i++) {
if(Books.get(i).getBookID()!= bookID){
successful = true;
} else {
System.out.println("This book ID already exists ");
}
}
} else { System.out.println("You must enter a number between 99 and 1000 ");
}
} while (successful == false);
do {
System.out.println("Please enter the name of book");
title = input.nextLine();
for (int i = 0; i < Books.size(); i++) {
if (Books.get(i).getTitle().equalsIgnoreCase(title)) {
System.out.println("ERROR: This book already exists");
successful = false;
} else {
successful = true;
}
}
} while (successful == false);
do {
System.out.println("Please enter the author of the book");
author = input.nextLine();
successful = true;
} while (successful == false);
Book Book = new Book(bookID, title, author, false, 0, 0);
Books.add(Book);
System.out.println(
"Book creation succcessful:" + "\nTitle: " + title + "\nAuthor: " + author + "\nBook ID:" + bookID);
}
public void loanBook() {
Scanner input = new Scanner(System.in);
boolean successful = false;
do {
System.out.println(
"\nPlease enter the book ID of the book that you wish to take out (Press 9 to exit to the main menu)");
int bookID = input.nextInt();
if (bookID == 9) {
successful = true;
break;
}
for (int i = 0; i < Books.size(); i++) {
if (Books.get(i).getBookID() == bookID) {
do {
System.out.println("\nHow long would you like to loan the book for (20 Days maximum):");
int durationOnLoan = input.nextInt();
if (durationOnLoan <= 20 && 1 <= durationOnLoan) {
Books.get(i).setDurationOnLoan(durationOnLoan);
successful = true;
} else {
System.out.println("The number of days you have entered is invalid");
}
} while (successful == false);
System.out.println("\nThe book " + Books.get(i).getTitle() + " is now on loan");
Books.get(i).setOnLoan(true);
Books.get(i).setNumOfLoan(Books.get(i).getNumOfLoans() + 1);
successful = true;
}
}
if (successful == false) {
System.out.println("This book does not exist ");
}
} while (successful == false);
}
public void returnBook() {
boolean successful = false;
Scanner input = new Scanner(System.in);
try {
do {
System.out.println(
"Please enter the book ID of the book you wish to return (Press 9 to exit to the main menu");
int bookID = input.nextInt();
input.nextLine();
if (bookID == 9) {
successful = true;
}
for (int i = 0; i < Books.size(); i++) {
if (Books.get(i).getBookID() == bookID) {
if (Books.get(i).getOnLoan() == true) {
System.out.println("How long did you loan the book for?");
int durationOnLoan = input.nextInt();
if (durationOnLoan > Books.get(i).getDurationOnLoan()) {
durationOnLoan -= Books.get(i).getDurationOnLoan();
if (durationOnLoan < 3) {
System.out.println("You are " + durationOnLoan
+ " day(s) late in returning the book" + "\nYou have been fined £3."
+ "\n The book " + Books.get(i).getTitle() + " is now returned");
successful = true;
} else {
System.out.println("You are " + durationOnLoan + " days late in returning the book"
+ "\nYou have been fined £6.");
System.out
.println("The book " + Books.get(i).getTitle() + " has now been returned");
successful = true;
}
} else {
Books.get(i).setOnLoan(false);
System.out.println("The book " + Books.get(i).getTitle() + " has now been returned");
successful = true;
}
} else if (Books.get(i).getOnLoan() == false) {
System.out.println("\nThis book was not on loan");
System.out.println("\nYou have been returned to the main menu");
successful = true;
}
} else if (successful == false) {
System.out.println("This book does not exist");
}
}
} while (successful == false);
} catch (Exception e) {
System.out.println("ERROR: Invalid input" + "\nYou have been returned to the main menu");
}
}
}
package assignment;
import java.nio.channels.MembershipKey;
import java.util.ArrayList;
import java.util.Scanner;
import org.omg.Messaging.SyncScopeHelper;
public class Library {
// Declared an array list of type book
private ArrayList<Book> Books;
private ArrayList<Member> members;;
public Library(ArrayList<Book> Books, ArrayList<Member> member) {
this.Books = Books;
this.members=member;
};
package assignment;
import java.nio.channels.MembershipKey;
import java.util.ArrayList;
import java.util.Scanner;
import org.omg.Messaging.SyncScopeHelper;
public class Library {
// Declared an array list of type book
private ArrayList<Book> Books;
private MemberList members;;
public Library(ArrayList<Book> Books, Member member) {
this.Books = Books;
this.members=members;
};
public void displayBooks() {
System.out.println("\t\t\t-----The Current Books in the library are-----");
for (int i = 0; i < Books.size(); i++) {
System.out.println("\n" + "\t\t" + Books.get(i).getTitle() + "\t\t\t" + "\n\t\tAuthor: "
+ Books.get(i).getAuthor() + "\n\t\tThis Books ID is: " + Books.get(i).getBookID() + "\t\t\t\t\t\t"
+ "\n\t\tIs this book on loan? " + Books.get(i).getOnLoan() + "\t\t\t\t\t"
+ "\n\t\tThe number of times which this book has been loaned: " + Books.get(i).getNumOfLoans()
+ "\t\t");
}
}
// method to remove permanently a book object
public void removeBook() // the parameter that is passed through
// is the book id of the book that is to
// be removed
{
Scanner input = new Scanner(System.in);
int bookID = 0;
boolean successful = false;
try {
do {
System.out.println("Please enter the book ID of the book you wish to delete");
bookID = input.nextInt();
for (int i = 0; i < Books.size(); i++) {
if (bookID == Books.get(i).getBookID())
{
System.out.println("The Book " + Books.get(i).getTitle() + " was removed");
Books.remove(i);
successful = true;
break;
}
}
if (!successful) {
System.out.println("Book ID " + bookID + " does not exist");
}
} while (successful == false);
} catch (Exception e) {
System.out.println("ERROR: Invalid input" + "\nYou have been returned to the main menu");
}
}
public void editBook() {
boolean successful = false;
try {
do {
Scanner sc = new Scanner(System.in);
System.out.println("Please enter the book ID of the book who's details you wish to change");
int bookID = sc.nextInt();
sc.nextLine();
for (int i = 0; i < Books.size(); i++) {
if (Books.get(i).getBookID() == bookID) {
System.out.println("Please enter the new name of the book:");
String newTitle = sc.nextLine();
Books.get(i).setTitle(newTitle);
System.out.println("Please enter the name of the author of the book:");
String newAuthor = sc.nextLine();
Books.get(i).setAuthor(newAuthor);
System.out.println("Change of book details successful" + "\nNew book title: " + newTitle
+ "\nNew author: " + newAuthor);
successful = true;
}
}
if (!successful) {
System.out.println("This book does not exist ");
}
} while (successful == false);
} catch (Exception e) {
System.out.println("ERROR: Invalid input" + "\nYou have been returned to the main menu");
}
}
public void addBook() {
boolean successful = false;
int bookID = 0;
String title = "";
String author = "";
Scanner input = new Scanner(System.in);
do {
System.out.println("Please assign a 3 digit number for the books ID ");
bookID = input.nextInt();
input.nextLine();
if(bookID > 99 && bookID <1000){
for (int i = 0; i < Books.size(); i++) {
if(Books.get(i).getBookID()!= bookID){
successful = true;
} else {
System.out.println("This book ID already exists ");
}
}
} else { System.out.println("You must enter a number between 99 and 1000 ");
}
} while (successful == false);
do {
System.out.println("Please enter the name of book");
title = input.nextLine();
for (int i = 0; i < Books.size(); i++) {
if (Books.get(i).getTitle().equalsIgnoreCase(title)) {
System.out.println("ERROR: This book already exists");
successful = false;
} else {
successful = true;
}
}
} while (successful == false);
do {
System.out.println("Please enter the author of the book");
author = input.nextLine();
successful = true;
} while (successful == false);
Book Book = new Book(bookID, title, author, false, 0, 0);
Books.add(Book);
System.out.println(
"Book creation succcessful:" + "\nTitle: " + title + "\nAuthor: " + author + "\nBook ID:" + bookID);
}
public void loanBook() {
Scanner input = new Scanner(System.in);
boolean successful = false;
do {
System.out.println(
"\nPlease enter the book ID of the book that you wish to take out (Press 9 to exit to the main menu)");
int bookID = input.nextInt();
if (bookID == 9) {
successful = true;
break;
}
for (int i = 0; i < Books.size(); i++) {
if (Books.get(i).getBookID() == bookID) {
do {
System.out.println("\nHow long would you like to loan the book for (20 Days maximum):");
int durationOnLoan = input.nextInt();
if (durationOnLoan <= 20 && 1 <= durationOnLoan) {
Books.get(i).setDurationOnLoan(durationOnLoan);
successful = true;
} else {
System.out.println("The number of days you have entered is invalid");
}
} while (successful == false);
System.out.println("\nThe book " + Books.get(i).getTitle() + " is now on loan");
Books.get(i).setOnLoan(true);
Books.get(i).setNumOfLoan(Books.get(i).getNumOfLoans() + 1);
successful = true;
}
}
if (successful == false) {
System.out.println("This book does not exist ");
}
} while (successful == false);
}
public void returnBook() {
boolean successful = false;
Scanner input = new Scanner(System.in);
try {
do {
System.out.println(
"Please enter the book ID of the book you wish to return (Press 9 to exit to the main menu");
int bookID = input.nextInt();
input.nextLine();
if (bookID == 9) {
successful = true;
}
for (int i = 0; i < Books.size(); i++) {
if (Books.get(i).getBookID() == bookID) {
if (Books.get(i).getOnLoan() == true) {
System.out.println("How long did you loan the book for?");
int durationOnLoan = input.nextInt();
if (durationOnLoan > Books.get(i).getDurationOnLoan()) {
durationOnLoan -= Books.get(i).getDurationOnLoan();
if (durationOnLoan < 3) {
System.out.println("You are " + durationOnLoan
+ " day(s) late in returning the book" + "\nYou have been fined £3."
+ "\n The book " + Books.get(i).getTitle() + " is now returned");
successful = true;
} else {
System.out.println("You are " + durationOnLoan + " days late in returning the book"
+ "\nYou have been fined £6.");
System.out
.println("The book " + Books.get(i).getTitle() + " has now been returned");
successful = true;
}
} else {
Books.get(i).setOnLoan(false);
System.out.println("The book " + Books.get(i).getTitle() + " has now been returned");
successful = true;
}
} else if (Books.get(i).getOnLoan() == false) {
System.out.println("\nThis book was not on loan");
System.out.println("\nYou have been returned to the main menu");
successful = true;
}
} else if (successful == false) {
System.out.println("This book does not exist");
}
}
} while (successful == false);
} catch (Exception e) {
System.out.println("ERROR: Invalid input" + "\nYou have been returned to the main menu");
}
}
}
package assignment;
import java.nio.channels.MembershipKey;
import java.util.ArrayList;
import java.util.Scanner;
import org.omg.Messaging.SyncScopeHelper;
public class Library {
// Declared an array list of type book
private ArrayList<Book> Books;
private ArrayList<Member> members;;
public Library(ArrayList<Book> Books, ArrayList<Member> member) {
this.Books = Books;
this.members=member;
};
包分配；
导入java.nio.channels.MembershipKey；
导入java.util.ArrayList；
导入java.util.Scanner；
导入org.omg.Messaging.SyncScopeHelper；
公共班级图书馆{
//声明了book类型的数组列表
私人ArrayList书籍；
私人ArrayList成员；；
公共图书馆（ArrayList图书，ArrayList会员）{
这个。书=书；
这个.成员=成员；
};
ArrayList<Member> List = new ArrayList<Member>();
MemberList memberList = new MemberList(List){};
ArrayList<Book> list = new ArrayList<Book>();
Library library = new Library(list, memberList ){};
ArrayList List=new ArrayList（）；
MemberList MemberList=新成员列表（列表）{}；
ArrayList=新建ArrayList（）；
Library Library=新库（列表，成员列表）{}；
错误显示“构造函数库（ArrayList，MemberList）未定义”，但我已更改了库类中的相关内容？您需要传递一个Book数组和一个成员：
public Library(ArrayList<Book> Books, Member member)
公共图书馆（ArrayList图书，会员）
public Library(ArrayList<Book> Books, Member member){};
公共图书馆（ArrayList图书，会员）{}；
您需要传递第二个参数，即成员类的对象。这里您错过了一个成员：
Library library = new Library(list, );
Member memberlist = new Member(10,"Joe Blogs", 44, 5, 0,"Bleaker Street",123456789);
Library library = new Library(list, memberlist);
您看到了什么错误？发布完整的错误消息，因为它们包含许多有用的信息，并经常告诉您错误的确切原因。您的库构造函数需要一个图书列表和一个成员：
Library Library=new Library（List，new Member（）；java.nio.channels.MembershipKeyorg.omg.Messaging.SyncScopeHelperArrayList成员ArrayList书籍公共库（ArrayList Books，ArrayList Member>members）{Library Library=new Library（list，memberList）；ArrayList memberList=new arrarylist（）； Member memberlist = new Member(10,"Joe Blogs", 44, 5, 0,"Bleaker Street",123456789);
Library library = new Library(list, memberlist);