Testing How Long This Takes...

to be visible in Google Reader

Testing cont

So obviously publish post and Atom feed updated together. Subscribe to feed in Google Reader gets it ASAP, what if already subscribed?

Seems that clicking on refresh even for a specific feed in Google Reader doesn't force a refresh of the feed at the back-end - 12mins and counting

Testing

Specifically the speed of new blog post -> visible in Atom feed -> visible in Google Reader

phoning

phoning
Originally uploaded by lomokev.

Hold on, just hold on!

Hold on, just hold on!
Originally uploaded by Funny Fish.

Flickr

This is a test post from , a fancy photo sharing thing.

Java Joe Closures - Quad Tree Example

There has been some discussion about the need for closures in Java, about whether they really would be useful to the great majority of Java programmers. Well I consider myself to write pretty straight-forward Java but I frequently find myself writing this sort of code.

Consider an example from the GIS arena. I have a 'quad-tree' spatial index and I want to be able to add content to the 'quad' that represents a particular lat/long point. I haven't written the quad-tree but it provides a convenience method to find a quad given a lat/long point:

// content to be stored on a quad
public class Content {}
public class Point {}


public class Quad {
   // quad on which content can be stored
  public void add(Content c) {}

  // convenience method for finding the relevant quad in the 
  // quad-tree based on a root quad and a lat/lng
  public void findQuad( 
                  Point pnt,
                  QuadListener listener );
}

// define a listener to be invoked when the correct quad 
// is found
public interface QuadListener {
  void foundQuad( Quad q );
}

If this was Javascript then I could use the classes that I have been supplied with to write a generic addContentToQuadTree() method as below:

function addContentToQuadTree( root,pnt,c ) {
  root.findQuad( pnt,function(q) { q.add(c); } );
}

To do the samething in Java I need to write:

// define a class to hold the content so it can be added to the quad
static class AddContentListener implements QuadListener {
  private final Content c;

  public AddContentListener( Content c ) {
    this.c = c;
  }

  public void foundQuad( Quad q ) {
    q.add( c );
  }
}

// high level method to add the specified content to the 
// quad defined by root and pnt
public void addContentToQuadTree( Quad root, Point pnt, Content c ) {
  root.findQuad( pnt,new AddContentListener( c ) );
}

Closures allow you to avoid defining this intermediate class.