Collections.sort在重写compare和compareTo后不起作用

Question

 package points;

 import java.util.Comparator;

 public class CompareY implements Comparator<Point>
 {
    public int compare(Point p1, Point p2)
    {
         int equals = 0;

    if(p1.getY() > p2.getY())
    {
        equals = 1;
    }
    else if(p1.getY()< p2.getY())
    {
        equals = -1;
    }
    else if(p1.getY() == p2.getY())
    {
        //If the 'Y's' are equal, then check the 'X's'
        if(p1.getX() > p2.getX())
        {
            equals = 1;
        }
        if(p1.getX() < p2.getX())
        {
            equals = -1;
        }
    }
    return equals;
  }
}

package points;

public class Point implements Comparable<Point>
{
    int x;
    int y;

public Point()
{
    //Blank default constructor
}
public Point(int x, int y)
{
    this.x = x;
    this.y = y;
}


//Auto generated getters and setters
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 int compareTo(Point o)
{
    int equals = 0;

    if(this.getX() > o.getX())
    {
        equals = 1;
    }
    else if(this.getX() < o.getX())
    {
        equals = -1;
    }
    else if(this.getX() == o.getX())
    {
        //If the 'X's' are equal, then check the 'Y's'
        if(this.getY()> o.getY())
        {
            equals = 1;
        }
        if(this.getY() < o.getY())
        {
            equals = -1;
        }
    }
    return equals;
  }

}

Collections.sort((List<Point>) linkedList);

测试代码：

package points;
import java.util.*;
import java.awt.Point;
public class Test
{

public static void main(String[] args) 
{
    Random rand = new Random();
    int sizeLimit = 10;

    LinkedList<Point> linkedList = new LinkedList<Point>();

    //Populating our linkedList with random values.
    for(int i=0; i < sizeLimit; i++)
    {
        linkedList.add(new Point(rand.nextInt(10), rand.nextInt(10)));
    }

    System.out.println("original list");

    //Declaring our iterator to step through and print out our elements
    Iterator<Point> iter = linkedList.iterator();
    while(iter.hasNext())
    {
        System.out.println(iter.next());
    }

    Collections.sort((List<Point>) linkedList);     

    }
}

Answer 1

导入java.awt.Point；

您导入了错误的Point类。代码现在不用你的了。

如果删除该行，将从当前包中获得point类。