尽量避免违反封装

问：

在 Java 中开始一些新东西，我有点困难。我觉得我走在正确的轨道上，只是出于某种原因，无法在不违反封装的情况下找到解决我所遇到的问题的方法。我有这两个类，分别称为 Weight 和 Project。我已经完成了这两个任务，但在 Project 类中出现错误。其中包括“toOunces”、“ounces”和“OUNCES_IN_A_POUND”。这些在 Weight 类中是私有的。我已经明白我不能继承私有变量、方法等。从一个班级到另一个班级。我只是不知道如何在不违反封装的情况下解决这个问题。下面我有 Weight 类和 Project 类以及作业详细信息。

我不是在寻找任何人为我做这项工作，因为我只是在寻找技巧、窍门和建议。另外，请耐心等待，因为我仍在学习 Java 语言，并且在 CMIS 242 的第一周。

public class Weight {

    //Private variables
    private static final int OUNCES_IN_A_POUND = 16;
    private int pounds;
    private double ounces;

    //A public parameterized constructor, which initializes the private variables.
    public Weight(int pounds, double ounces) {
        this.pounds = pounds;
        this.ounces = ounces;
        normalize();
    }

    //instance methods
    private double toOunces() {
        return (pounds * OUNCES_IN_A_POUND) + ounces;
    }

    private void normalize() {
        while (ounces >= OUNCES_IN_A_POUND) {
            pounds++;
            ounces -= OUNCES_IN_A_POUND;
        }
    }

    public boolean lessThan(Weight weight) {
        double thisOunces = toOunces();
        double otherOunces = weight.toOunces();
        return thisOunces < otherOunces;
    }

    public void addTo(Weight weight) {
        double thisOunces = toOunces();
        double otherOunces = weight.toOunces();
        double totalOunces = thisOunces + otherOunces;

        pounds = (int) (totalOunces / OUNCES_IN_A_POUND);
        ounces = totalOunces % OUNCES_IN_A_POUND;
        normalize();
    }

    public String toString() {
        return pounds + " pounds and " + String.format("%.2f", ounces) + " ounces";
    }
}

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public class Project {
    private static Weight findMinimum(Weight weight1, Weight weight2, Weight weight3) {
        Weight minimumWeight = weight1;

        if (weight2.lessThan(minimumWeight)) {
            minimumWeight = weight2;
        }

        if (weight3.lessThan(minimumWeight)) {
            minimumWeight = weight3;
        }

        return minimumWeight;
    }

    private static Weight findMaximum(Weight weight1, Weight weight2, Weight weight3) {
        Weight maximumWeight = weight1;

        if (weight2.toOunces() > maximumWeight.toOunces()) {
            maximumWeight = weight2;
        }

        if (weight3.toOunces() > maximumWeight.toOunces()) {
            maximumWeight = weight3;
        }

        return maximumWeight;
    }

    private static Weight findAverage(Weight weight1, Weight weight2, Weight weight3) {
        double totalOunces = weight1.toOunces() + weight2.toOunces() + weight3.toOunces();
        double averageOunces = totalOunces / 3.0;

        int averagePounds = (int) (averageOunces / Weight.OUNCES_IN_A_POUND);
        double averageOuncesRemaining = averageOunces % Weight.OUNCES_IN_A_POUND;

        return new Weight(averagePounds, averageOuncesRemaining);
    }


    public static void main(String[] args) {
        //instances of the weight class
        Weight weight1 = new Weight(11, 3);
        Weight weight2 = new Weight(7, 20);
        Weight weight3 = new Weight(14, 6);

        System.out.println("Weight 1: " + weight1.toString());
        System.out.println("Weight 2: " + weight2.toString());
        System.out.println("Weight 3: " + weight3.toString());

        Weight minimumWeight = findMinimum(weight1, weight2, weight3);
        System.out.println("The minimum weight is " + minimumWeight.toString());

        Weight maximumWeight = findMaximum(weight1, weight2, weight3);
        System.out.println("The maximum weight is " + maximumWeight.toString());

        Weight averageWeight = findAverage(weight1, weight2, weight3);
        System.out.println("The average weight is " + averageWeight.toString());
    }
}

作业详情的 PDF 文件链接：https://learn.umgc.edu/d2l/common/viewFile.d2lfile/Database/NzQ5OTk1NjE/Assignment1.pdf?ou=1016228