Java帐户程序-无法访问类型为的封闭实例

第07行-我得到以下错误：

无法访问Exercise10_7类型的封闭实例

我如何解决这个问题？此外，完成后，我需要修改它持有一个4选项菜单（检查余额，提取，存款，退出）10个帐户数组。如果我能得到一些指导来实现这一点，那将是非常棒的

import java.util.Date;

public class Exercise10_7 {

    public static void main(String[] args) {

    Account account1 = new Account(1122, 20000, .045);
    account1.withdraw(2500);
    account1.deposit(3000);
    java.util.Date dateCreated = new java.util.Date();

    System.out.println("Date Created:" + dateCreated);
    System.out.println("Account ID:" + account1.id);
    System.out.println("Balance:" + account1.getBalance());
    System.out.println("Interest Rate:" + account1.getAnnualInterestRate());
    System.out.println("Balance after withdraw of 2500:" +       account1.getAnnualInterestRate());
    System.out.println("Balance after deposit of 3000:" + account1.getAnnualInterestRate());
    System.out.println("Monthly Interest:" + account1.id);
    System.out.println("Process completed.");
    }

    class Account {
        //define variables
        private int id;
        private double balance; // balance for account
        private double annualInterestRate; //stores the current interest rate
        private Date dateCreated; //stores the date account created

        //no arg construtor
        Account () {
            id = 0;
            balance = 0.0;
            annualInterestRate = 0.0;
        }
        //constructor with specific id and initial balance
        Account(int newId, double newBalance) {
            id = newId;
            balance = newBalance;
        }
        Account(int newId, double newBalance, double newAnnualInterestRate) {
            id = newId;
            balance = newBalance;
            annualInterestRate = newAnnualInterestRate;
        }
        //accessor/mutator methods for id, balance, and annualInterestRate
        public int getId() {
            return id;
        }
        public double getBalance() {
            return balance;
        }
        public double getAnnualInterestRate() {
            return annualInterestRate;
        }
        public void setId(int newId) {
            id = newId;
        }
        public void setBalance(double newBalance) {
            balance = newBalance;
        }
        public void setAnnualInterestRate(double newAnnualInterestRate) {
            annualInterestRate = newAnnualInterestRate;
        }
        //accessor method for dateCreated
        public void setDateCreated(Date newDateCreated) {
            dateCreated = newDateCreated;
        }
        //define method getMonthlyInterestRate
        double getMonthlyInterestRate() {
            return annualInterestRate/12;
        }
        //define method withdraw
        double withdraw(double amount) {
            return balance -= amount;
        }   
        //define method deposit
        double deposit(double amount) {
            return balance += amount;   
        }
    }
}

---

因为

Account

是一个内部类，所以需要一个封闭类的实例来体现它。或者您可以将

Account

设置为静态类。你可以改变

class Account {

到

或更改

Account account1 = new Account(1122, 20000, .045);

到

说（部分）

内部类是未显式或隐式声明为静态的嵌套类

---

您无法访问静态方法中的非静态字段/属性，

main

方法是静态的，而您的内部类是非静态的。你有两个选择

使您的内部类成为静态的

从类的对象访问内部类。e、 g

YourInnerClass obj=new OuterClass（）。新建YourInnerClass（参数）

---

非常感谢你。所以显式声明为“静态类帐户”，隐式声明为“新的Exercise10_7（）。新帐户”？可能重复的

Account account1 = new Account(1122, 20000, .045);

Account account1 = new Exercise10_7().new Account(1122, 20000, .045);