小弟KANGTA问题，付程序代码！

Question

public class TryPolyLine
{
public static void main(String[] args)
{
TryPolyLine tpl = new TryPolyLine();
Point[] coords={tpl.new Point(1.0,1.0), tpl.new Point(2.0,2.0), tpl.new Point(3.0,3.0), tpl.new Point(4.0,4.0), tpl.new Point(5.0,5.0), tpl.new Point(6.0,6.0)};
TryPolyLine.PolyLine polygon=tpl.new PolyLine(coords);
System.out.println(polygon);
polygon.addPoint(tpl.new Point(7.0,7.0));
System.out.println(polygon);
Point[] points=new Point[coords.length];
for(int i=0;i<points.length;i++)
{
points[i]=tpl.new Point(coords[i].x,coords[i].y);
TryPolyLine.PolyLine newPoly=tpl.new PolyLine(points);
System.out.println(newPoly);
}
}

class Point
{
public Point(double xVal,double yVal)
{
    x=xVal;
y=yVal;
} public Point(Point point)
{
    x=point.x;
y=point.y;
} public String tostring()
{
  return x+","+y;
} protected double x;
protected double y;
} class ListPoint
{
public ListPoint(Point point)
{
    this.point=point;
next=null;
} public void setNext(ListPoint next)
{
    this.next=next;
} public ListPoint getNext()
{
return next;
} public String tostring()
{
    return "("+point+")";
} private ListPoint next;
private Point point;
} class PolyLine
{
public ListPoint start;
public ListPoint end;

public PolyLine(Point[] points)
{
if(points!=null)
{
start=new ListPoint(points[0]);
end=start;
for(int i=1;i<points.length;i++)
{
addPoint(points[i]);
}
}
} public void addPoint(Point point)
{
ListPoint newEnd=new ListPoint(point);
if(start==null)
start=newEnd;
else
end.setNext(newEnd);
end=newEnd;
} public String tostring()
{
StringBuffer str=new StringBuffer("PolyLine:");
ListPoint nextPoint=start;
while(nextPoint!=null)
{
str.append(" "+nextPoint);
nextPoint=nextPoint.getNext();
}
return str.toString();
}
}}//这是我修改过后的，自己对照一下吧

Answer 1

public class TryPolyLine
{
    public TryPolyLine()
    {
        Point[] coords={new Point(1.0,1.0),new Point(2.0,2.0),new Point(3.0,3.0),new Point(4.0,4.0),new Point(5.0,5.0),new Point(6.0,6.0)};
        PolyLine polygon=new PolyLine(coords);
        System.out.println(polygon);
        polygon.addPoint(new Point(7.0,7.0));
        System.out.println(polygon);
        Point[] points=new Point[coords.length];
        for(int i=0;i<points.length;i++)
        {
            points[i]=new Point(coords[i].x,coords[i].y);
            PolyLine newPoly=new PolyLine(points);
            System.out.println(newPoly);
        }
    }
    public static void main(String[] args)
    {
        TryPolyLine tpl = new TryPolyLine();
    }    private class Point
    {
        public Point(double xVal,double yVal)
        {
            x=xVal;
            y=yVal;
        }
        public Point(Point point)
        {
            x=point.x;
            y=point.y;
        }
        public String tostring()
        {
            return x+","+y;
        }
        protected double x;
        protected double y;
    }
    public class ListPoint
    {
        public ListPoint(Point point)
        {
            this.point=point;
            next=null;
        }
        public void setNext(ListPoint next)
        {
            this.next=next;
        }
        public ListPoint getNext()
        {
            return next;
        }
        public String tostring()
        {
            return "("+point+")";
        }
        private ListPoint next;
        private Point point;
    }
    public class PolyLine
    {
        public ListPoint start;
        public ListPoint end;
        public PolyLine(Point[] points)
        {
            if(points!=null)
            {
                start=new ListPoint(points[0]);
                end=start;
                for(int i=1;i<points.length;i++)
                {
                    addPoint(points[i]);
                }
            }
        }
            public void addPoint(Point point)
            {
                ListPoint newEnd=new ListPoint(point);
                if(start==null)
                    start=newEnd;
                else
                    end.setNext(newEnd);
                end=newEnd;
            }
            public String tostring()
            {
                StringBuffer set=new StringBuffer("PolyLine:");
                ListPoint nextPoint=start;
                while(nextPoint!=null)
                {
                    set.append(" "+nextPoint);
                    nextPoint=nextPoint.getNext();
                }
                return set.toString();
            }
    }
}

Answer 2

GJA106(中文字符) 哥哥，你改了只后，我就理解了，怪不得原来的代码我在传递参数的时候就？？？？？？？？？？？？？？？？？？不明白。可是我是照着书打的啊《java编程指南jdk1.3版》哦！