主要方法 DriverMortgageClass.java

Question

我即将完成此程序，但无法运行，因为它需要一个 main 方法。但是，每当我输入它时，我都会收到错误代码 illegal start of expression。有人可以指出此代码片段中主要方法所属的位置吗？下面是我写的代码。我还被指示使用 Javadoc 实用工具，但我仍然不确定它是什么以及如何使用它。我相信我使用 java.util.doc

走在正确的轨道上

import javax.swing.*;
import java.text.*;
import java.util.*;

public class DriverMortgageClass
{


   public double annualInterestRate;
   public int numberOfYears;
   public double loanAmount;
   public double monthlyPayment;
   public double totalPayment;

  
   //set decimal format
   DecimalFormat df= new DecimalFormat ("0.00");
   
   private Mortgage mortgage;
   
   public DriverMortgageClass()
   {
   
   mortgage = new Mortgage();
   }

public void start()
{
  
//get input for interest rate
String annualInterestRateString = JOptionPane.showInputDialog(null,"Enter yearly interest rate, for example 8.25",JOptionPane.QUESTION_MESSAGE);
annualInterestRate=Double.parseDouble(annualInterestRateString);
mortgage.setAnnualInterestRate(annualInterestRate);

//get input for number of years
String numberOfYearsString = JOptionPane.showInputDialog(null,"Enter number of years as an integer, for example 5",JOptionPane.QUESTION_MESSAGE);
numberOfYears= Integer.parseInt(numberOfYearsString);
mortgage.setNumberOfYears(numberOfYears);

//set loan amount
String loanAmountString = JOptionPane.showInputDialog(null,"Enter loan amount, for example 120000.95",JOptionPane.QUESTION_MESSAGE);
loanAmount= Integer.parseInt(loanAmountString);
mortgage.setLoanAmount(loanAmount);


//calculate the monthly and total payment
monthlyPayment=loanAmount*annualInterestRate /(1-(Math.pow(1/(1+annualInterestRate),numberOfYears*12)));
totalPayment=monthlyPayment*numberOfYears*12;

//display monthly and total payment
JOptionPane.showMessageDialog(null,"The monthly payment is"+monthlyPayment 
+"The total payment is"+totalPayment);
       

System.exit(0);
}// end main method
}

Answer 1

it needs a main method

然后添加一个main方法和JavaDoc

/**
*  This is a JavaDoc. Describe the class here. 
*
**/
public class DriverMortgageClass
{


    // Other code...

    public static void main(String[] args) {
        new DriverMortgageClass().start();
    } 
}

主要方法 DriverMortgageClass.java

Main method DriverMortgageClass.java

java

main-method