Question

我正在尝试在java程序中创建几个点。点的坐标位于文本文件中，我扫描并按编号读取。

   double x = 0.0;
   double y = 0.0;

   Point origin = new Point(x, y);
   Point[] points = new Point[1000]; // There are 1000 points in total, thus 2000 doubles, this array will be used to store all the points

   Scanner keyboard = new Scanner(System.in);
   String FileName = keyboard.nextLine();       
   Scanner linReader = new Scanner(new File(FileName));

   while (linReader.hasNextDouble()) {     
       x = linReader.nextDouble();
       y = linReader.nextDouble(); 

       origin = (x, y); // error telling me 'cannot convert from double to point'
       }

我收到错误＆＃34;无法从双重转换为某个点＆＃34;所以我需要知道如何修复此错误？我可以使用双打坐标作为分数吗？

Answer 1

Point等级不会给出双精度。对于双精度，您需要使用Point2D.Double类。请考虑以下代码作为示例。

    static void pointTest() {
      double x = 1.2;
      double y = 3.4;
      Point2D.Double pointDouble = new Point2D.Double(x, y);
      System.out.println(pointDouble);
    }

Answer 2

public static void  main(String args[]) {

    //// Alternative 1 
    double x = 9.7;
    double y = 8.6;

    //import com.sun.javafx.geom.Point2D;
    Point2D point2D = new Point2D();
    point2D.x = (float) x; point2D.y= (float) y;


    ///// Alternative 2 (lose some accuracy) 
    //use Double object   
    Double x1 = 9.7;
    Double y1 = 8.6;
    //import java.awt.Point;
    Point origin = new Point(x1.intValue(), y1.intValue());
}

Answer 3

使用此类：

import org.springframework.data.geo.Point;

行家：

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

Answer 4

似乎更直截了当地这样做：

List<Point> points = new ArrayList<Point>(1000);

...

    points.add(new Point(x, y));

Answer 5

这是最低限度的变革解决方案：

   double x = 0.0;
   double y = 0.0;

   Point origin;
   Point[] points = new Point[1000]; // There are 1000 points in total, thus 2000 doubles, this array will be used to store all the points

   Scanner keyboard = new Scanner(System.in);
   String FileName = keyboard.nextLine();       
   Scanner linReader = new Scanner(new File(FileName));

   while (linReader.hasNextDouble()) {     
       x = linReader.nextDouble();
       y = linReader.nextDouble(); 

       origin  = new Point(x, y);
       }

你也可以实现自己的Point类，就像这样

    public class Point {

      double x;
      double y;

     public Point(double x, double y){
       this.x = x;
       this.y = y;
     }

     public double getX(){
       return this.x;          
     }

     public double getY(){
       return this.y;          
     }
   }

希望这有帮助

如何在一个点存储双打？

5 个答案: