这道JAVA编程题代码要怎么写求代码

package test;
public class Plane {
	double startPos;
	double startSpeed;
	double advance;
	
	public Plane(double startPos,double startSpeed,double advance)
	{
		this.startPos=startPos;
		this.startSpeed=startSpeed;
		this.advance=advance;
	}
	
	public double arrive(double destPos)
	{
		double time;
		time = (-startSpeed+(Math.sqrt(startSpeed*startSpeed+2*advance*(destPos-startPos))))/(advance);
		return time;
	}
	
	public double chase(Plane plane)
	{
		double distance = plane.startPos-this.startPos;
		double dspeed=-(plane.startSpeed-this.startSpeed);
		double dadv = -(plane.advance-this.advance);
		double time=0.0;
		time=(-dspeed+(Math.sqrt(dspeed*dspeed+2*dadv*(distance))))/dadv;
		return time;
	}
	
	public static void main(String[] args) {
		Plane p1 = new Plane(1.0,2.0,0.5);
		System.out.println(p1.arrive(3.0));
		System.out.println(p1.chase(new Plane(5.0,1.5,0.3)));
	}
}

以上是代码测试