Java账户类程序

Java account class program

提问by user3739072

I have wrote this program over and over again, can someone please tell me what I am missing, it looks like its a small error I am not catching.

我一遍又一遍地编写了这个程序，有人可以告诉我我遗漏了什么，它看起来像是一个我没有发现的小错误。

Here is what I am trying to accomplish:

这是我想要完成的：

Design a class named Account that contains:

设计一个名为 Account 的类，其中包含：

• A private int data field named id for the account(default 0)
• A private double data field named balance for the account (default 0)
• A private double data field named annualInterestRate that stores the current interest rate (default 0). Assume all accounts have the same interest rate.
• A private Date data field named dateCreated that stores the date when the account was created. A no-arg constructor that creates a default account.
• A constructor that creates an account with the specific id and initial balance.
• The accessor and mutator methods for id, balance, and annualInterestRate.
• The accessor method for dateCreated
• A method named getMonthlyInterestRate() that returns the monthly interest rate.
• A method named withdraw that withdraws a specified amount from the account A method named deposit that deposits a specified amount to the account.
• Write a test program that creates an Account object with an account ID of 1122, a balance of $20,000, and an annual interest rate of 4.5%. Use the withdraw method to withdraw $2,500, use the deposit method to deposit $3,000 and print the balanace, the monthly interest, and the date when this account was created.

• 帐户的一个名为 id 的私有 int 数据字段（默认为 0）
• 帐户的名为 balance 的私有双数据字段（默认为 0）
• 一个名为 yearInterestRate 的私有双数据字段，用于存储当前利率（默认为 0）。假设所有账户的利率相同。
• 一个名为 dateCreated 的私有日期数据字段，用于存储创建帐户的日期。创建默认帐户的无参数构造函数。
• 创建具有特定 ID 和初始余额的帐户的构造函数。
• id、balance 和annualInterestRate 的访问器和修改器方法。
• dateCreated 的访问器方法
• 一个名为 getMonthlyInterestRate() 的方法，它返回月利率。
• 一种从账户中提取指定金额的名为withdraw 的方法 一种名为deposit 的方法，用于将指定金额存入账户。
• 编写一个测试程序，创建一个账户对象，账户 ID 为 1122，余额为 20,000 美元，年利率为 4.5%。使用提款方式提取2,500美元，使用存款方式存入3,000美元并打印余额、每月利息和创建此帐户的日期。

Here is what I have so far:

这是我到目前为止所拥有的：

import java.util.Date;

public class Assign22 {

public static void main(String[] args) {
    // TODO Auto-generated method stub

Account account1 = new Account(1122, 20000, .045);
account1.withdraw(2500);
account1.deposit(3000);
System.out.println("Date Created:" + java.util.Date dateCreated = new java.util.Date());
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;   
}
}

}

This is the error that I am receiving: Not sure what I missed here:

这是我收到的错误：不确定我在这里错过了什么：

"Syntax error on token "Date", , expected after this token dateCreated cannot be resolved to a variable at Assign22.main(Assign22.java:12)"

“令牌“日期”上的语法错误，在此令牌 dateCreated 之后预期无法解析为 Assign22.main(Assign22.java:12) 处的变量”

回答by Sotirios Delimanolis

You can't have variable declarations as part of Stringconcatenation expressions

您不能将变量声明作为String串联表达式的一部分

System.out.println("Date Created:" + java.util.Date dateCreated = new java.util.Date());

Split that up

把它分开

java.util.Date dateCreated = new java.util.Date()
System.out.println("Date Created:" + dateCreated);