附件是我为Lab项目完成的代码。我已完成所有工作，但由于某种原因我的代码处于闲置状态？我认为这可能是“ bank1”和“ bank2”对象与Bank类之间的问题吗？
我很抱歉代码很长，因为我不知道问题出在哪里。请帮助：（
货币兑换类（主要）
import javax.swing.*;
import java.io.FileNotFoundException;
import java.util.*;
public class CurrencyExchange {
public static void main(String [] args) throws FileNotFoundException {
//Create 2 bank objects, one for each file "bank1.txt" & "bank2.txt"
Bank bank1 = new Bank("bank1.txt");
Bank bank2 = new Bank("bank2.txt");
int userCont = 0;
do {
boolean buy = false;
double amount;
int banksSupported = 0;
String currencyCode;
Scanner keyboard = new Scanner(System.in);
String userAnswer;
//Ask user to buy or sell - use continue to repeat loop if invalid
System.out.println("Do you want to buy or sell?");
userAnswer = keyboard.nextLine();
if (!userAnswer.equalsIgnoreCase("buy") && (!userAnswer.equalsIgnoreCase("sell")) ) {
System.out.println("Invalid response. Please enter buy or sell. ");
continue;
}
if (userAnswer.equalsIgnoreCase("buy")) {
buy = true;
}
//Ask user for foreign currency - use continue to repeat loop if invalid
System.out.println("Which currency would you like to use?");
currencyCode = keyboard.nextLine().toUpperCase();
//Check and Print how many banks support the users currency - use continue to repeat loop if none
if(bank1.supportCurrency(currencyCode))
++banksSupported;
if(bank2.supportCurrency(currencyCode))
++banksSupported;
if (banksSupported == 0) {
System.out.println("There are no banks the support " + currencyCode + ". Please enter a different currency.");
continue;
}
else if (banksSupported == 1) {
System.out.println("One bank supports " + currencyCode + ".");
}
else {
System.out.println("Two banks support " + currencyCode + ".");
}
//Prompt the user for the amount of foreign currency and get the user input
System.out.println(" What amount of " + currencyCode + "?");
amount = keyboard.nextDouble();
//Use the quoteBuy or quoteSell methods of the Bank objects to get a Quote from every bank supporting the foreign currency.
//Print the quote(s) from the bank(s), using the toString method of the Quote object(s).
if(buy) {
if (bank1.supportCurrency(currencyCode)) {
System.out.println(bank1.quoteBuy(amount, currencyCode));
}
if (bank2.supportCurrency(currencyCode)) {
System.out.println(bank2.quoteBuy(amount, currencyCode));
}
}
else {
if (bank1.supportCurrency(currencyCode)) {
System.out.println(bank1.quoteBuy(amount, currencyCode));
}
if (bank2.supportCurrency(currencyCode)) {
System.out.println(bank2.quoteBuy(amount, currencyCode));
}
}
//Use the console to prompt the user for another transaction.
userCont = JOptionPane.showConfirmDialog(null, "Would you like to preform another transaction?", "Contniue", JOptionPane.YES_NO_OPTION);
} while(userCont == 0); // while ( the user wants to continue performing transactions )
}
}
银行类
import java.io.*;
import java.util.*;
public class Bank {
// Five private data fields: The name of the bank, The commission rate, Three fields for the three currencies exchanged by the bank.
// Each of these should have type Currency.
private String bankName;
private double commissionRate;
private Currency currencyCode1;
private Currency currencyCode2;
private Currency currencyCode3;
public Bank(String fileA) throws FileNotFoundException {
File bankFile = new File(fileA);
Scanner keyboard = new Scanner(System.in);
this.bankName = keyboard.nextLine();
this.commissionRate = Double.parseDouble((keyboard.nextLine()));
this.currencyCode1 = new Currency(keyboard.next(), Double.parseDouble(keyboard.next()));
this.currencyCode2 = new Currency(keyboard.next(), Double.parseDouble(keyboard.next()));
this.currencyCode3 = new Currency(keyboard.next(), Double.parseDouble(keyboard.next()));
keyboard.close();
}
public boolean supportCurrency(String currencyCode) {
return currencyCode.equalsIgnoreCase(currencyCode1.getCurrencyCode())
|| currencyCode.equalsIgnoreCase(currencyCode2.getCurrencyCode())
|| currencyCode.equalsIgnoreCase(currencyCode3.getCurrencyCode());
}
// Working on getRate method.
public double getRate(String currencyCode) {
double bankExchangeRate = -1.0;
if (currencyCode.equalsIgnoreCase(currencyCode1.getCurrencyCode())) {
bankExchangeRate = currencyCode1.getExchangeRate();
}
else if (currencyCode.equalsIgnoreCase(currencyCode2.getCurrencyCode())) {
bankExchangeRate = currencyCode2.getExchangeRate();
}
else if (currencyCode.equalsIgnoreCase(currencyCode3.getCurrencyCode())) {
bankExchangeRate = currencyCode3.getExchangeRate();
}
return bankExchangeRate; //return -1.0
}
public Quote quoteBuy(double amt, String currencyCode) {
double rate = getRate(currencyCode);
Quote quote;
if(rate == -1.0) {
quote = null;
}
else {
double userOwes = amt / (rate * (1 - commissionRate)); // This calculates the commission amount based on the dollar amount.
double commission = userOwes * commissionRate;
quote = new Quote(bankName, "USD", userOwes, currencyCode, amt, commissionRate, commission);
}
return quote;
}
public Quote quoteSell(double amt, String currencyCode) {
double rate = getRate(currencyCode);
Quote quote;
if(rate == -1.0) {
quote = null;
}
else {
double base = amt / rate; // This calculates the dollar value of the foreign currency.
double commission = commissionRate * base; // This calculates the commission amount based on the dollar amount.
double amtConverted = base - commission; // The bank takes a cut.
quote = new Quote(bankName, currencyCode, amt, "USD", amtConverted, commissionRate, commission);
}
return quote;
}
}
货币类
public class Currency {
// Two private data fields, one to hold the currency code and one to hold the exchange rate.
// Note that the exchange rate for the same currency could be different for different banks
private final String currencyCode;
private final double exchangeRate;
// A constructor that takes two arguments: the currency code and exchange rate.
// The constructor should assign the private members from the values of the arguments.
public Currency(String currencyCode, double currencyExchangeRate) {
this.currencyCode = currencyCode;
this.exchangeRate = currencyExchangeRate;
}
// An accessor method (getter) for each data field.
public String getCurrencyCode() {
return currencyCode;
}
public double getExchangeRate() {
return exchangeRate;
}
}
报价类
import java.text.DecimalFormat;
public class Quote {
private String bankName;
private String codeToBank;
private double amtToBank;
private String codeFromBank;
private double amtFromBank;
private double commissionRate;
private double commissionAmt$;
DecimalFormat decimalFormat;
public Quote(String bankName, String currencyCode, double amt, String usd, double amtConverted, double commissionRate, double commission) {
this.bankName = bankName;
this.codeToBank = currencyCode;
this.amtToBank = amt;
this.codeFromBank = usd;
this.amtFromBank = amtConverted;
this.commissionRate = commissionRate;
this.commissionRate = commission;
this.decimalFormat = new DecimalFormat("0.00");
}
public String toString() {
return (this.bankName + " is willing to offer you " + decimalFormat.format(this.amtFromBank)
+ " " + this.codeFromBank + " for "
+ decimalFormat.format(this.amtToBank) + " "
+ this.codeToBank + ", after collecting a commission of "
+ decimalFormat.format(this.commissionRate)
+ " USD (" + Math.round(100 * this.commissionRate) + "%)");
}
}
答案 0 :(得分：1)
您的问题是，扫描仪应从System.in中读取，而应从输入文件“ bank1.txt”或“ bank2.txt”中读取。
更改银行中的这一行：
扫描仪键盘=新的Scanner（System.in）;
对此：
扫描仪键盘=新的扫描仪（bankFile）;
您的代码将按预期工作。