Java 如何使用多种方法？

所以，我必须为一个视频商店写一张发票，它有一个Customer类，它有六个属性，客户名称（字符串）、街道地址（字符串）、城市（字符串）、州（字符串）、邮政编码（字符串）和电话号码。我必须使用一个参数化的构造函数来接收属性作为参数，并提供getter和setter。我相信我做得对

接下来，我必须制作一个视频类，它有四个属性：视频名称（字符串）、视频发布年份（整数）、视频拷贝数（整数）和每日租金（双倍）。我还必须为此做一个参数化构造函数、getter和setter

问题从我的Invoice类开始，该类表示向给定客户出租视频，它还没有完成，但应该有四个属性，客户出租视频、正在出租的视频、出租日期（作为输入字符串）和每日出租率（双倍）。它也应该有三种方法，小计，税和总数。我的问题是我已经为客户和视频设置了预设的方法，我只是不知道如何在if语句中有效地使用它们。我不知道我会在我的第四节测试课上放些什么来让它起作用。在这一点上我几乎不知所措，任何朝着正确方向的努力都将不胜感激。这是我的课

客户：

public class Customer {
private String customerName;
private String streetAddress;
private String custCity;
private String custState;
private String custZip;
private String custPhone;
public Customer(String customerName, String streetAddress, String custCity, String custState, String custZip,
        String custPhone) {
    super();
    this.customerName = customerName;
    this.streetAddress = streetAddress;
    this.custCity = custCity;
    this.custState = custState;
    this.custZip = custZip;
    this.custPhone = custPhone;
}
public String getCustomerName() {
    return customerName;
}
public void setCustomerName(String customerName) {
    this.customerName = customerName;
}
public String getStreetAddress() {
    return streetAddress;
}
public void setStreetAddress(String streetAddress) {
    this.streetAddress = streetAddress;
}
public String getCustCity() {
    return custCity;
}
public void setCustCity(String custCity) {
    this.custCity = custCity;
}
public String getCustState() {
    return custState;
}
public void setCustState(String custState) {
    this.custState = custState;
}
public String getCustZip() {
    return custZip;
}
public void setCustZip(String custZip) {
    this.custZip = custZip;
}
public String getCustPhone() {
    return custPhone;
}
public void setCustPhone(String custPhone) {
    this.custPhone = custPhone;
}



}

视频：

public class Video {
private String videoName;
private int videoYear;
private int copyNum;
private double rentalRate;
public Video(String videoName, int videoYear, int copyNum, double rentalRate) {
    super();
    this.videoName = videoName;
    this.videoYear = videoYear;
    this.copyNum = copyNum;
    this.rentalRate = rentalRate;
}
public String getVideoName() {
    return videoName;
}
public void setVideoName(String videoName) {
    this.videoName = videoName;
}
public int getVideoYear() {
    return videoYear;
}
public void setVideoYear(int videoYear) {
    this.videoYear = videoYear;
}
public int getCopyNum() {
    return copyNum;
}
public void setCopyNum(int copyNum) {
    this.copyNum = copyNum;
}
public double getRentalRate() {
    return rentalRate;
}
public void setRentalRate(double rentalRate) {
    this.rentalRate = rentalRate;
}

发票（不完整）：

程序4（不完整）：

---

你在学习面向对象，对吗？构造类的一种方法是让Invoice类包含一个Customer对象和几个视频对象（列表）。然后，您可以创建添加/删除视频和打印/删除发票的方法。@heniv181是的，我是。我该如何着手构建这样的东西？对不起，我对这个还比较陌生，我觉得我只是错过了一些在我得到它之后看起来很简单的东西

    import java.util.Scanner;

public class Invoice {
     public static void main(String[] args){
    Scanner in = new Scanner(System.in);
    Customer Brandon = new Customer("Brandon James" , "112 Oak Street" 
        , "CityVille" , "Alabama" , "18229",
        "912-2248");

Customer Judy = new Customer("Judy Vermooth" , "8008 Ribbit Ln.",
        "Metropolis" , "Pennsylvania" , "24057", "241-8009");

Video Easter = new Video("Easter 2", 2002, 4, 2.49);

Video DareDevil3 = new Video ("Dare Devil 3", 2012, 2, 3.62);




if( Prog4.newRental = "Brandon"){
    Customer Brandon = newCust

}
}
}

import java.util.*;

public class Prog4 {
private String newRental;
private String vidName;
private String rentalDate;
private String daysRented;

public static void main(String[] args){
Scanner in = new Scanner(System.in);


System.out.println("Enter Customer Name: ");
 String newRental = in.nextLine();

System.out.println("Enter Video Name: ");
String vidName = in.nextLine();

System.out.println("Enter Rental date in mm/dd/yyyy format: ");
String rentalDate = in.nextLine();

System.out.println("Enter Number of Days Rented");
int daysRented = in.nextInt();
}

public String getNewRental() {
    return newRental;
}

public void setNewRental(String newRental) {
    this.newRental = newRental;
}

public String getVidName() {
    return vidName;
}

public void setVidName(String vidName) {
    this.vidName = vidName;
}

public String getRentalDate() {
    return rentalDate;
}

public void setRentalDate(String rentalDate) {
    this.rentalDate = rentalDate;
}

public String getDaysRented() {
    return daysRented;
}

public void setDaysRented(String daysRented) {
    this.daysRented = daysRented;
}

}