油漆转换 (JAVA NETBEANS)

Question

我正在尝试做一个油漆转换项目。 最终我会制作一个 GUI，但我想先充实它。 我在下面有代码。 有没有人可以简化这一点，而不仅仅是拥有一堆不同的方法？ 下面将主要介绍 class 和方法 class ，它显示了我如何计算所有内容。 原谅我第一次在这里发布问题的任何乱七八糟的格式。

package paintconversion;

/** @author JoshS */
public class Paint2Quart {

  private double Quart;
  private double Gallon;
  private double Pint;

  public Paint2Quart() {
    Quart = 0;
    Gallon = 0;
    Pint = 0;
  }
  // Method to convert Quart to Gallon
  public void setQuartToGallon(double conQuart) {
    if (conQuart > 0) {
      Quart = conQuart / 4;
      System.out.println(conQuart + " quart equals " + Quart + " Gallon(s)");
    } else {
      System.out.println("Numbers Must Be Positive!");
    }
  }
  // Method to convert Gallon To Quart
  public void setGallonToQuart(double conGallon) {
    if (conGallon > 0) {
      Gallon = conGallon * 4;
      System.out.println(conGallon + " gallon equals " + Gallon + " Quart(s)");
    } else {
      System.out.println("Numbers Must Be Positive!");
    }
  }

  public void setPintToGallon(double conPint) {
    if (conPint > 0) {
      Pint = conPint / 8;
      System.out.println(conPint + " pint equals " + Pint + " Gallon(s)");
    } else {
      System.out.println("Numbers Must Be Positive!");
    }
  }

  public void setPintToQuart(double conPint) {
    if (conPint > 0) {
      Pint = conPint / 2;
      System.out.println(conPint + " pint equals " + Pint + " Quart(s)");
    } else {

      System.out.println("Numbers Must Be Positive!");
    }
  }

  public void setGallonToPint(double conGallon) {
    if (conGallon > 0) {
      Gallon = conGallon * 8;
      System.out.println(conGallon + " Gallon equals " + Gallon + " Pint(s)");
    } else {

      System.out.println("Numbers Must Be Positive!");
    }
  }

  public void setQuartToPint(double conQuart) {
    if (conQuart > 0) {
      Pint = conQuart * (2);
      System.out.println(conQuart + " Quart equals " + Pint + " Pint(s)");
    } else {

      System.out.println("Numbers Must Be Positive!");
    }
  }
}

Answer 1

我会将所有数量转换为幕后的通用单位，然后根据需要将它们转换回来。 比如说，在一个名为 Volume 的 class 中：

public class Volume {
    private double gallons;

    private Volume(double gallons) {
        if (gallons < 0) {
            throw new IllegalArgumentException("value must be positive");
        }
        this.gallons = gallons;
    }

    public static Volume ofGallons(double gallons) {
        return new Volume(gallons);
    }

    public static Volume ofQuarts(double quarts) {
        return new Volume(quarts / 4);
    }

    public static Volume ofPints(double pints) {
        return new Volume(pints / 8);
    }

    public static Volume ofLiters(double liters) {
        return new Volume(0.264172 * liters);
    }

    public double asGallons() {
        return gallons;
    }

    public double asQuarts() {
        return gallons * 4;
    }

    public double asPints() {
        return gallons * 8;
    }

    public double asLiters() {
        return gallons / 0.264172;
    }

    @Override
    public String toString() {
        return gallons + " gallon" + (gallons == 1 ? "" : "s");
    }
}

然后，要将体积从品脱转换为夸脱：

quarts = Volume.ofPints(pints).asQuarts();