I've been working for my final essay, building a Java program to implement a K-means algorithm, and I got stuck on this error:
object cannot be converted to point.
And this is code where my error is
public void plotCluster() {
System.out.println("[Cluster: " + id+"]");
System.out.println("[Centroid: " + centroid + "]");
System.out.println("[Points: \n");
for(Point p : points) { // error
System.out.println(p);
}
System.out.println("]");
}
From you comment, you mention that you declare your list like this:
public List points;
and I'll assume that later, you do:
points = new ArrayList();
A List is a generic class, and the type parameter says what type of object the list holds. If you don't specify the type parameter, it defaults to Object.
You should declare your list with the type parameter:
public List<Point> points;
points = new ArrayList<>(); // note the <>
In your current code, you've got a raw list (defaulting to holding Object), and that's why for(Point p : points) fails to type check. As far as the compiler is concerned, the list holds Object and thus you cannot assigned it to p which has type Point.
