我似乎无法弄清楚为什么当我清楚地覆盖了相等方法时，我总是得到真

问：

我试图弄清楚这一点，但我似乎无法正确比较它。

当我尝试在运行时设置代码时，当我需要它来生成错误测试时，结果最终会变成 True。广泛的测试表明它始终是正确的，我不知道如何对它产生错误。

import java.util.Scanner;

public class LandTract
{
    // instance variables
    private static double length , width, area;

    /**
     * Constructor for objects of class LandTract
     */
    public LandTract(double length, double width, double area)
    {
        // initialise instance variables
        length = 0;
        width = 0;
    }

    public LandTract(double length, double width)
    {
        this.length = length;
        this.width = width;
    }
    
    public void setLength(double length)
    {
        this.length = length;
    }
    
    public double getLength()
    {
        return length;
    }
    
    public void setWidth(double width)
    {
        this.width = width;
    }
    
    public double getWidth()
    {
        return width;
    }
    
    public double getArea()
    {
        return area = length * width;
    }
    
    public String toString()
    {
        String str = "Length: " + length + "\nWidth: " + width;
        return str;
    }
    
    public boolean equals(Object obj)
    {
        LandTract land = (LandTract) obj;
        if (this.length != land.length)
            return false;
        if (this.width != land.width)
            return false;
        if (this.area != land.area)
            return false;
        
            return true;
    }
    
    public static void main(String[] args)
    {
        Scanner key = new Scanner(System.in);
        
        System.out.print("Enter the length of the first tract of land: ");
        length = key.nextDouble();
        key.nextLine();
        System.out.print("Enter the width of the first tract of land: ");
        width = key.nextDouble();
        key.nextLine();
        LandTract land1 = new LandTract(length , width);
        System.out.println("The area of the first tract of land is " + land1.getArea());
        System.out.println();
        
        System.out.print("Enter the length of the second tract of land: ");
        length = key.nextDouble();
        key.nextLine();
        System.out.print("Enter the width of the second tract of land: ");
        width = key.nextDouble();
        key.nextLine();
        LandTract land2 = new LandTract(length, width);
        System.out.println("The area of the second tract of land is " + land2.getArea());
        System.out.println();
        
        if (land1.equals(land2))
            System.out.println("Both tracts of land are the same size.");
        else
            System.out.println("They are different sizes.");
    }
}