An arraylist always comes along with class

Question

class Points {
int x,y;
}
void setup () {
size(700,700);
background(255);
}
ArrayList<Points> points = new ArrayList ();

void draw (){
if ( points.size()==0)
return;
Points p = points.get(0);
for (int i = 0 ; i< points.size(); i ++) {
Points p3 = points.get(i);
connect(p,p3);
p=p3;
}
}`

//THE ABOVE CODE LOOKS FINE UNTIL I REPLACE THE EIGHTH LINE BY :
ArrayList points = new ArrayList ();
The problem is that I can't access to the arraylist
The error is like "Type mismatch , "Java.lang.Object " does not macth with "mypdefile"
Clear explanations or a particular example are preferred over abstract ones
Thank you in advance

Answer 1

what is mypdefile. Question is not properly explained.