我正在尝试为类Bank Bank实现Comparable的接口，我覆盖了Bank帐户的compareTo方法，但在尝试使用Collections.sort时，我收到错误：
BankAccountTester.java:40: error: no suitable method found for sort(ArrayList<BankAccount>)
Collections.sort(list);
为什么会这样？
我的代码位于银行帐户和测试人员的下方：
/**
A class to test the BankAccount class.
*/
import java.util.ArrayList;
import java.util.Collections;
public class BankAccountTester
{
public static void main(String[] args)
{
BankAccount bank1 = new BankAccount(30);
BankAccount bank2 = new BankAccount(15);
BankAccount bank3 = new BankAccount(10);
BankAccount bank4 = new BankAccount(5);
BankAccount bank5 = new BankAccount(20);
// Put the rectangles into a list
ArrayList<BankAccount> list = new ArrayList<BankAccount>();
list.add(bank1);
list.add(bank2);
list.add(bank3);
list.add(bank4);
list.add(bank5);
// Call the library sort method
Collections.sort(list);
// Print out the sorted list
for (int i = 0; i < list.size(); i++)
{
BankAccount b = list.get(i);
System.out.println(b.getBalance());
}
}
}
银行帐户类：
/**
A bank account has a balance that can be changed by
deposits and withdrawals.
*/
public class BankAccount implements Comparable<BankAccount>
{
private double balance;
/**
Constructs a bank account with a zero balance.
*/
public BankAccount()
{
// this.balance = 0;
this(0);
}
/**
Constructs a bank account with a given balance.
@param initialBalance the initial balance
*/
public BankAccount(double balance)
{
this.balance = balance;
}
/**
Deposits money into the bank account.
@param amount to deposit
*/
public void deposit(double amount)
{
balance = balance + amount;
}
/**
Withdraws money from the bank account.
@param amount to withdraw
*/
public void withdraw(double amount)
{
balance = balance - amount;
}
/**
Gets the current balance of the bank account.
@return the current balance
*/
public double getBalance()
{
return balance;
}
public int compareTo(BankAccount otherObject) {
BankAccount other = (BankAccount) otherObject;
if (this.balance < other.balance) { return -1; }
if(this.balance > other.balance) { return 1; }
return 0;
}
}