到目前为止,我已经创建了两个类,下面将显示
我已经测试了两个类,它们似乎都可以工作.
我现在需要创建一个菜单,该菜单将使用我创建的两个类,并允许用户输入信息并在其帐户中找到以下信息：
>添加客户详细信息
>存入公司账户
>将抄表记录到企业帐户
>显示商家帐户的当前余额
>显示完整的帐户详细信息
>更改企业帐户的折扣值
>更改所有企业帐户的单位成本
>如何使用菜单系统
虽然我已尽力寻找如何使用在线资源来做到这一点,但我目前迷失了.到目前为止,每次尝试创建菜单系统时,我都无法正常工作.如果有人可以在如何做的基础上帮助我,我将不胜感激.
谢谢 ：)
public class GasAccount
{
private int intAccRefNo;
private String strName;
private String strAddress;
public double dblBalance;
private double dblUnits;
public static double dblUnitsCosts = 0.02;
public GasAccount (int intNewAccRefNo , String strNewName , String strNewAddress)
{
}
public GasAccount (int intNewAccRefNo , String strNewName , String strNewAddress , double dblNewUnits)
{
intAccRefNo = intNewAccRefNo;
strName = strNewName;
strAddress = strNewAddress;
dblUnits = dblNewUnits;
dblBalance = dblUnits * dblUnitsCosts;
}
public int getAccRefNo()
{
return intAccRefNo;
}
public String getName()
{
return strName;
}
public String getAddress()
{
return strAddress;
}
public void deposit(double dblDepositAmount)
{
dblBalance = dblBalance - dblDepositAmount;
}
public double getBalance()
{
return dblBalance;
}
public double getUnitCost()
{
return dblUnitsCosts;
}
public void recordUnits (double dblUnitsUsed)
{
dblBalance = dblBalance + dblUnitsUsed * dblUnitsCosts;
dblUnits = dblUnitsUsed + dblUnits;
}
public double getUnits()
{
return dblUnits;
}
public void updateUnitsCosts(double dblNewUnitsCosts)
{
this.dblUnitsCosts = dblNewUnitsCosts;
}
}
另一个扩展了它-
public class BusinessAccount extends GasAccount
{
private double dblDiscount;
public BusinessAccount (int intNewAccRefNo, String strNewName, String strNewAddress, double dblNewUnits, double dblNewDiscount)
{
super (intNewAccRefNo , strNewName , strNewAddress, dblNewUnits);
dblDiscount = dblNewDiscount;
}
public void setNewDiscount(double dblNewDiscount)
{
dblDiscount = dblNewDiscount;
}
public double getDiscount()
{
return dblDiscount;
}
@Override
public void recordUnits (double dblUnitsUsed)
{
double dblNewBalance;
dblBalance = dblBalance + dblUnitsUsed * dblUnitsCosts;
dblNewBalance = dblUnitsUsed * dblUnitsCosts * dblDiscount / 100;
dblBalance = dblBalance - dblNewBalance;
}
这是我尝试的菜单,直到第五个选项为止.我从其他类中调用方法时发生了严重错误,因为BuisnessAccount.getMethod始终显示为错误.我也很确定再次声明变量是完全错误的,因为它们与我的其他类没有链接.
如果有人可以帮助我解决这个问题,将不胜感激
import java.util.Scanner;
public class Menu
{
public static void main(String [] args)
{
Scanner input = new Scanner(System.in);
int Choice;
{
System.out.println("------------------------------");
System.out.println ( "1. Add the customers details" ) ;
System.out.println ( "2. Make a deposit to the business account" );
System.out.println ( "3. Record a meter reading to the business account" ) ;
System.out.println ( "4. Display current balance of the business account" ) ;
System.out.println ( "5. Display full account details" ) ;
System.out.println ( "6. Change the discount value for the business account" ) ;
System.out.println ( "7. Change the cost per unit for all business accounts ");
System.out.println ( "8. How to use the menu system ");
System.out.println ( "Any other number will exit the program");
System.out.println("------------------------------");
System.out.println ( "\n\nEnter a number from 1 to 8" );
Choice = input.nextInt();
switch (Choice)
{
case 1 :
int intNewAccRefNo;
String strNewName;
String strNewAddress;
Double dblNewUnits;
Double dblNewDiscount;
System.out.println("Please enter the account number?");
intNewAccRefNo = input.nextInt();
System.out.println("Please enter the account name?");
input.nextLine();
strNewName = input.nextLine();
System.out.println("Please enter the account address?");
strNewAddress = input.nextLine();
System.out.println("Please enter the number of initial number of units used?");
dblNewUnits = input.nextDouble();
System.out.println("Please enter the discount?");
dblNewDiscount = input.nextDouble();
case 2:
double dblDeposit;
System.out.println("Please enter the amount you want to deposit?");
dblDeposit = input.nextDouble();
System.out.println ( "The current balance: " + BusinessAccount.getBalance() ) ;
case 3:
double dblUnits;
System.out.println("Enter the number of Units Used");
dblUnits = input.nextDouble();
BusinessAccount.recordUnits(dblUnits);
case 4:
System.out.println("\n Current Balance: £"+ BusinessAccount.getBalance());
case 5:
System.out.println("Account Reference Number: " + BusinessAccount.getAccRefNo());
System.out.println("Address: " + BusinessAccount.getAddress());
System.out.println("Name: " + BusinessAccount.getName());
System.out.println("Balance: " + BusinessAccount.getBalance());
System.out.println("Discount: " + BusinessAccount.getDiscount());
System.out.println("Units: " + BusinessAccount.getUnits());
case 1 :
String strAddress;
System.out.println("Please enter the account address?");
strAddress = input.nextLine();
System.out.println("Address:" + firstAccount.getAddress());
用户输入的内容和我正在调用的方法之间没有任何联系,不确定如何解决.
解决方法:
通过使用BusinessAccount.someMethod(),您试图在静态上下文中调用所述方法,但是您的方法不是静态的.要调用您的方法,您需要使它们静态化,或者需要创建一个对象然后可以对其进行调用,即：
BusinessAccount ba= new BusinessAccount (4, "name", "address", 3.4, 43.4);
ba.someMethodFromClass();
在您的情况下,您不希望它们是静态的.阅读有关静态方法/变量的更多信息(请参见下文).
一些文档可能会有所帮助：
http://docs.oracle.com/javase/tutorial/java/javaOO/classvars.html
http://docs.oracle.com/javase/7/docs/api/javax/swing/JMenu.html
要回答第二个问题,您需要有一个方法(在对象的类中,而不是在main中),该方法可以为变量分配值.即：
public void setAddress (String address)
{
strAddress=address;
}
然后,将将从main读取的地址传递给函数.通过这样做,您正在将用户的值初始化/分配给您类中存储的值,即：
System.out.println("Please enter the account address?");
String temp = input.nextLine();
ba.setAddress(temp);
System.out.println("Address:" + ba.getAddress());
甚至更好
System.out.println("Please enter the account address?");
ba.setAddress(input.nextLine());
System.out.println("Address:" + ba.getAddress());