java将 Point3d 类中"public void setX(double value) { this.x = value; }"继承Point2d中
时间: 2024-05-10 09:15:54 浏览: 13
可以使用Java中的继承机制来实现这个功能。在Point3d类中继承Point2d类,然后可以直接访问Point2d类中的属性和方法。因此,可以省略Point3d类中setX方法的实现,直接使用Point2d类中已经实现的setX方法来完成这个功能。代码示例如下:
```
public class Point3d extends Point2d {
private double z;
public Point3d(double x, double y, double z) {
super(x, y);
this.z = z;
}
public double getZ() {
return z;
}
public void setZ(double z) {
this.z = z;
}
}
```
在这个示例中,Point3d类继承了Point2d类,并且拥有Point2d类中的所有属性和方法。因此,可以直接使用Point2d类中的setX方法来设置x属性的值。
相关问题
仔细阅读以下所给的代码,完善Point类,在Point类中覆盖Object的toString()和equals()方法,使得编译执行主类Test输出如下结果: public class Test{ public static void main(String[] args){ Point pt1=new Point(12,24,36); Point pt2=new Point(12,24,36); System.out.println("pt1:"+pt1); System.out.println("pt1.equals(pt2):"+ pt1.equals(pt2)); } } class Point{ private double x; private double y; private double z; public Point(){} public Point(double x,double y,double z){ this.x=x; this.y=y; this.z=z; } public double getX(){return this.x;} public void setX(double x){this.x=x;} public double getY(){return this.y;} public void setY(double y){this.y=y;} }
完善后的代码如下:
```
public class Test{
public static void main(String[] args){
Point pt1=new Point(12,24,36);
Point pt2=new Point(12,24,36);
System.out.println("pt1:"+pt1);
System.out.println("pt1.equals(pt2):"+ pt1.equals(pt2));
}
}
class Point{
private double x;
private double y;
private double z;
public Point(){}
public Point(double x,double y,double z){
this.x=x;
this.y=y;
this.z=z;
}
public double getX(){return this.x;}
public void setX(double x){this.x=x;}
public double getY(){return this.y;}
public void setY(double y){this.y=y;}
public double getZ(){return this.z;}
public void setZ(double z){this.z=z;}
@Override
public String toString() {
return "Point [x=" + x + ", y=" + y + ", z=" + z + "]";
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Point other = (Point) obj;
if (Double.doubleToLongBits(x) != Double.doubleToLongBits(other.x))
return false;
if (Double.doubleToLongBits(y) != Double.doubleToLongBits(other.y))
return false;
if (Double.doubleToLongBits(z) != Double.doubleToLongBits(other.z))
return false;
return true;
}
}
```
输出结果为:
```
pt1:Point [x=12.0, y=24.0, z=36.0]
pt1.equals(pt2):true
```
其中,Point类中覆盖了Object的toString()和equals()方法,toString()方法返回一个字符串,表示该点的x、y、z坐标值,equals()方法判断两个Point对象是否相等,如果它们的x、y、z坐标值都相等,则返回true,否则返回false。在测试主类Test中,创建了两个Point对象pt1和pt2,它们的坐标值都相等,因此调用equals()方法返回true。在输出pt1时,调用了Point类的toString()方法,返回了该点的x、y、z坐标值。
public class Node { private int x; private int y; Image img; public Node(){ } public Image getImg() { return img; } public void setImg(Image img) { this.img = img; } public Node(int x, int y){ this.x=x; this.y=y; } public int getX() { return x; } public void setX(int x) { this.x = x; } 给这段代码加入图片
你可以使用 ImageIO 类加载图片,然后将其赋值给 Node 类中的 Image 类型的 img 属性。具体的代码实现可以参考下面的示例:
```
import java.awt.Image;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class Node {
private int x;
private int y;
private Image img;
public Node() {
}
public Node(int x, int y) {
this.x = x;
this.y = y;
}
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
public Image getImg() {
return img;
}
public void setImg(Image img) {
this.img = img;
}
public static void main(String[] args) {
Node node = new Node(10, 20);
try {
Image img = ImageIO.read(new File("path/to/image.jpg"));
node.setImg(img);
} catch (IOException e) {
e.printStackTrace();
}
}
}
```
其中,我们使用 ImageIO 类的 read 方法从文件系统中加载图片,并将其赋值给 Node 类中的 img 属性。你需要将 "path/to/image.jpg" 替换为实际的图片路径。