java代码——判断点是否在定直线上

import java.awt.Point;
import java.util.Scanner;
public class Exercise4 {

public static void main(String[] args) {
Scanner scan=new Scanner(System.in);
//point点类
Point point1=new Point();
Point point2=new Point();
double x,y;


//给point类赋值
point1.setLocation(5.0,5.0);
point2.setLocation(1.0,1.0);//确定定直线
System.out.print("请分别输入点的x,y坐标:");
x=scan.nextDouble();
y=scan.nextDouble();

//判断一个点是否在定直线上
boolean pdline=(x-point1.getX())*(point1.getY()-point2.getY())==(point1.getX()-point2.getX())*(y-point1.getY());
if(pdline){
System.out.println("您输入的点在该条直线上");
}
else{
System.out.println("您输入的点不在该条直线上");
}
scan.close();
}
}