我试图创建一个不断重复的银行记录，直到用户输入命令Q退出。我的while循环看起来很好但是它只重复两次然后停止。此外，我正在尝试编写一个打印列表，根据姓氏组织名称。我尝试按照姓氏打印它，但它不会根据姓氏打印。
我的主要课程代码：
public static void main(String args[]){
LinkedList<Customer2> bankRecords = new LinkedList<>();
Scanner input=new Scanner(System.in);
System.out.println("Enter Command");
String x=input.nextLine();
while(true){
if(x.equals("a")){
if(bankRecords.isEmpty()){
System.out.println("Records are empty");
System.out.println("Enter a command");
x=input.nextLine();
}else {
printList(bankRecords);
System.out.println("a Show all records");
System.out.println("r Remove the current record");
System.out.println("f Change the first name in the current record");
System.out.println("l Change the last name in the current record");
System.out.println("n Add a new record");
System.out.println("d Add a deposit to the current record");
System.out.println("w Make a withdrawal from the current record");
System.out.println("s Select a record from the record list to become the current record");
System.out.println("Enter a command");
}
}
if(x.equals("r")){
bankRecords.removeLast();
System.out.println("a Show all records");
System.out.println("r Remove the current record");
System.out.println("f Change the first name in the current record");
System.out.println("l Change the last name in the current record");
System.out.println("n Add a new record");
System.out.println("d Add a deposit to the current record");
System.out.println("w Make a withdrawal from the current record");
System.out.println("s Select a record from the record list to become the current record");
System.out.println("Enter a command");
x=input.nextLine();
}
if (x.equals("f")) {
Customer2 currentRecord = bankRecords.getLast();
System.out.print("Enter Firstname: ");
String fname=input.nextLine();
currentRecord.setFirstName(fname);
currentRecord.menu();
System.out.println("Enter a command");
x=input.nextLine();
}
if (x.equals("l")) {
Customer2 currentRecord = bankRecords.getLast();
System.out.print("Enter Last Name: ");
String lname=input.nextLine();
currentRecord.setLastName(lname);
currentRecord.menu();
System.out.println("Enter a command");
x=input.nextLine();
}
if(x.equals("d")){
Customer2 currentRecord = bankRecords.getLast();
System.out.print("Enter deposited amount");
int deposit=input.nextInt();
currentRecord.deposit(deposit);
currentRecord.menu();
System.out.println("Enter a command");
x=input.nextLine();
}
if(x.equals("w")){
Customer2 currentRecord = bankRecords.getLast();
System.out.print("Enter Withdrawn amount");
int withdraw=input.nextInt();
currentRecord.withdraw(withdraw);
currentRecord.menu();
System.out.println("Enter a command");
x=input.nextLine();
}
if(x.equals("n")){
System.out.print("Enter first name: ");
String name=input.nextLine();
System.out.println("Enter Last name");
String lname=input.nextLine();
System.out.print("Enter Balance:");
int balance=input.nextInt();
bankRecords.add(new Customer2(name, lname, balance));
System.out.println("a Show all records");
System.out.println("r Remove the current record");
System.out.println("f Change the first name in the current record");
System.out.println("l Change the last name in the current record");
System.out.println("n Add a new record");
System.out.println("d Add a deposit to the current record");
System.out.println("w Make a withdrawal from the current record");
System.out.println("s Select a record from the record list to become the current record");
System.out.println("Enter a command");
x=input.nextLine();
}
if(x.equals("q")){
return;
}
if(x.equals("s")){
System.out.println("Enter first name");
String fname=input.nextLine();
for(int i=0;i<bankRecords.size();i++){
if(bankRecords.contains(fname)){
Customer2 cur=bankRecords.getLast();
}}}}}
public static void printList(LinkedList<Customer2> list) {
for (Customer2 data : list) {
System.out.println(data.getFirstName()+"\t"+data.getLastName()+"\t"+data.getAccountBalance());
}
}
我的第二堂课：
public class Customer2 {
private String firstName;
private String lastName;
private int accountBalance;
public int total=0;
public Customer2(String fName, String lName, int balance){
firstName = fName;
lastName = lName;
accountBalance = balance;
}
public void setFirstName(String newFirstName){
firstName = newFirstName;
}
public void setLastName(String newLastName){
lastName = newLastName;
}
public String getFirstName() {
return firstName;
}
public String getLastName() {
return lastName;
}
public double getAccountBalance() {
return accountBalance;
}
public void withdraw(int amount){
total=accountBalance-amount;
accountBalance=total;
}
public void deposit(int amount){
total=accountBalance+amount;
accountBalance=total;
}
public void menu(){
System.out.println("a Show all records");
System.out.println("r Remove the current record");
System.out.println("f Change the first name in the current record");
System.out.println("l Change the last name in the current record");
System.out.println("n Add a new record");
System.out.println("d Add a deposit to the current record");
System.out.println("w Make a withdrawal from the current record");
System.out.println("s Select a record from the record list to become the current record");
}
}
答案 0 :(得分：0)
你的第一部分非常混乱，难以理解。它甚至没有运行两个周期，我的特殊情况是它运行到你的电脑。如果您可以清除代码并使其可理解，则可以回答。对于第二部分，您需要基于姓氏的排序列表。为此，您需要为您的Customer2类实现Comparable。
public class Customer2 implements Comparable<Customer2>{
private String firstName;
private String lastName;
private int accountBalance;
public int total=0;
public Customer2(String fName, String lName, int balance){
firstName = fName;
lastName = lName;
accountBalance = balance;
}
public void setFirstName(String newFirstName){
firstName = newFirstName;
}
public void setLastName(String newLastName){
lastName = newLastName;
}
public String getFirstName() {
return firstName;
}
public String getLastName() {
return lastName;
}
public double getAccountBalance() {
return accountBalance;
}
public void withdraw(int amount){
total=accountBalance-amount;
accountBalance=total;
}
public void deposit(int amount){
total=accountBalance+amount;
accountBalance=total;
}
public void menu(){
System.out.println("a Show all records");
System.out.println("r Remove the current record");
System.out.println("f Change the first name in the current record");
System.out.println("l Change the last name in the current record");
System.out.println("n Add a new record");
System.out.println("d Add a deposit to the current record");
System.out.println("w Make a withdrawal from the current record");
System.out.println("s Select a record from the record list to become the current record");
}
@Override
public int compareTo(Customer2 o) {
// TODO Auto-generated method stub
return o.lastName.compareTo(lastName);
}
}
然后，在您的主类中，您可以使用Collection对列表进行排序。我还附上了修改后的部分
public static void printList(LinkedList<Customer2> list) {
Collections.sort(list);
System.out.println(list);
}