我正在搞乱BlueJ，试图让对象互相交流。我创建了一个帐户和帐户列表类。帐户列表允许您添加帐户对象，然后将其放入arraylist。
通过索引从数组中删除这些帐户很容易，使用for循环来获取每个帐户的位置，但是现在它应该删除指定为参数的帐号的帐户，我无法弄清楚如何从数组中获取accountnumber以将其与用户输入进行比较。
AccountList类
/**
* Creates an AccountList that will store customers accounts
*
* @author Ryan Conway
* @version 12/11/2014
*/
import java.util.*;
public class AccountList
{
private ArrayList < Account > accounts;
/**
* Create an AccountList that will contain accounts.
*/
public AccountList()
{
accounts = new ArrayList < Account >();
}
/**
* Add a account to this AccountList.
*/
public void addAccount(Account newAccount)
{
accounts.add(newAccount);
}
/**
* Return the number of accounts stored in this AccountList.
*/
public int getNumberOfAccounts()
{
return accounts.size();
}
/**
* prints out the number of accounts to the terminal.
* for each loop used to get each account.
*/
public void getAllAccounts()
{
for(Account account : accounts)
{
account.printAccountDetails();
}
System.out.println("Number of accounts: " + getNumberOfAccounts());
}
/**
* Print out details of a account
* @param accountEntry The entry in the list
*/
public void getAccount(int accountEntry)
{
if(accountEntry < 0)
{
System.out.println("Negative entry :" + accountEntry);
}
else if(accountEntry < getNumberOfAccounts())
{
Account account = accounts.get(accountEntry);
account.printAccountDetails();
}
else
{
System.out.println("No such entry :" + accountEntry);
}
}
/**
* removes a account from the list
* @param accountEntry The entry in the list
*/
public void removeAccount(int accountEntry)
{
if(accountEntry < 0)
{
System.out.println("Negative entry :" + accountEntry);
}
else if(accountEntry < getNumberOfAccounts())
{
accounts.remove(accountEntry);
}
else
{
System.out.println("No such entry :" + accountEntry);
}
}
public boolean removeAccount(String accountNumber)
{
int index = 0;
for(Account account : accounts)
{
if (accounts.equals(accountNumber))
System.out.println("Found It!");
index++;
}
return false;
}
public void printCollection()
{
System.out.println(accounts);
}
}
帐户类
/**
* Write a description of class Account here.
*
* @author (your name)
* @version (a version number or a date)
*/
public class Account
{
private String firstName;
private String lastName;
private String accountNumber;
private int pointsHeld;
private Address address;
/**
* Constructor for objects of class Account.
* The number of pointsHeld should be set to zero.
*
* @param firstName The Account Holder's first name
* @param lastName The Account Holder's last name
* @param accNumber The Account Holder's account number
* @param street the account holder's street
* @param town the account holder's town
* @param postcode the account holder's postcode
*/
public Account(String fName, String lName, String accNumber,
String street, String town, String postcode)
{
firstName = fName;
lastName = lName;
accountNumber = accNumber;
pointsHeld = 0;
address = new Address(street, town, postcode);
}
/**
* Constructor for objects of class Account.
* The number of pointsHeld should should be set to
* the supplied value.
*
* @param fName The Account Holder's first name
* @param lName The Account Holder's last name
* @param acctNumber The account number
* @param thePoints the pointsHeld awarded when account is initialised
* @param street the account holder's street
* @param town the account holder's town
* @param postcode the account holder's postcode
*/
public Account(String fName, String lName, String acctNumber, int points,
String street, String town, String postcode)
{
firstName = fName;
lastName = lName;
accountNumber = acctNumber;
pointsHeld = points;
address = new Address(street, town, postcode);
}
// accessors
/**
* Get the Account Holder's first name
*
* @return the Account Holder's first name
*/
public String getFirstName()
{
return firstName;
}
/**
* Get the Account Holder's last name
*
* @return the Account Holder's last name
*/
public String getLastName()
{
return lastName;
}
/**
* Get the Account Holder's account Number
*
* @return the Account Holder's account number
*/
public String getAccountNumber()
{
return accountNumber;
}
/**
* Get the number of points held
*
* @return the number of points held
*/
public int getNoOfPoints()
{
return pointsHeld;
}
/**
* Print out the Account Holder's details to the console window
*
*/
public void printAccountDetails()
{
System.out.println( firstName + " " + lastName
+ "\n" + address.getFullAddress()
+ "\nAccount Number: " + accountNumber
+ "\nNumber of points: " + pointsHeld);
}
/**
* Return the account holder's address
*
* @return the account holder's address
*/
public String getAddress()
{
return address.getFullAddress();
}
// mutators
/**
* Change the first name
*
* @param fName the new first name
*
*/
public void setFirstName(String fName)
{
firstName = fName;
}
/**
* Change the last name
*
* @param lName the new last name
*
*/
public void setLastName(String lName)
{
lastName = lName;
}
/**
* Increase the number of points held by a given number
* and output a esage to the console window giving
* the revised number of points held.
*
* @param number of points to add to total
*/
public void addPoints(int points)
{
pointsHeld = pointsHeld + points;
System.out.println("Points now held: " + pointsHeld);
}
/**
* Remove pointsHeld by a given number and output a
* message to the console window giving the revised number
* of points held as long as the number of points would
* not fall below zero
* - otherwise output message to console window instead.
*
* @param number of pointsHeld to remove total.
*
*/
public void removePoints (int points)
{
if ((pointsHeld - points) >=0)
{
pointsHeld = pointsHeld - points;
System.out.println("Points now held: " + pointsHeld);
}
else
{
System.out.println("Transaction refused: "
+ "Insufficient points available.");
}
}
/**
* Change the account holder's address
*
* @param street the street
* @param town the town
* @postcode the postcode
*/
public void setAddress(String street, String town, String postcode)
{
address.setFullAddress(street, town, postcode);
}
/**
* Print the account holder's address
*/
public void printAddress()
{
address.printAddress();
}
} // end class
http://i.imgur.com/dCwt9oK.jpg
感谢。
答案 0 :(得分：1)
试试这个：
public boolean removeAccount(String accountNumber)
{
Iterator<Account> iterator = accounts.iterator();
while (iterator.hasNext())
{
if (accountNumber.equals(iterator.next().getAccountNumber()))
{
System.out.println("Found It!");
iterator.remove();
return true;
}
}
return false;
}
在循环中从列表中删除项目不是一种安全的操作，但Iterator类使这成为可能。更多信息：Iterating through a Collection, avoiding ConcurrentModificationException when removing in loop