Handy But Hidden: Collections.newSetFromMap()

I was reminded again today of how much the core Java libraries have grown over the years.  It can be really hard to keep track of all the nice little features that get added in each release.  Today, I was wishing that there was a ConcurrentHashSet class or some other HashSet-style concurrent collection.  Before implementing something myself, I did some searching on Google and found a nice way to solve the problem.  In Java 6 (a.k.a. JDK 1.6), Sun added the utility method Collections.newSetFromMap(), which allows you to pass in an empty backing Map and get out a Set with behavior based on the underlying Map.  So, here is all I needed to do to build a concurrent HashSet:

Set<Observer> observers = Collections.newSetFromMap(new ConcurrentHashMap<Observer, Boolean>());

I also found a bug/enhancement request in Sun's bug database suggesting that this feature should be documented in any core Map for which there is no corresponding Set implementation, such as WeakHashMap and IdentityHashMap.  Given how long I went without knowing the method existed, I wish they'd done it.

MorphLabs, the Meta-Cloud Vendor?

Fascinating!  I just got an email from G2iX, the parent company of MorphLabs, inviting me to a webinar (Wed, Dec. 9, 2009 from 11AM - 12PM PST) in which they plan to demonstrate how to "Morph your Data Center into a Cloud Vendor":

Traditional data center and co-location vendors are under tremendous threat in the face of Amazon EC2 and related Web Services, and those providers who’re unable to adapt to some sort of cloud computing model face extinction as competing Infrastructure as a Service products become even more prevalent.

This webinar will demonstrate how the Morph Cloud Computing Platform can help regional data centers transform their business using their existing assets with minimal cost and hardware investments so that they can provide a cutting edge cloud solution to a broader customer base with rates that are more than competitive while still maintaining great profit margin.

For those who are unfamiliar with the company, MorphLabs provides a hosting platform that runs on top of Amazon's EC2 web service.  So, assuming I'm not mistaken, G2iX plans to help data centers other than Amazon's set up the Morph platform to run on their own servers.  My first thought was, "Why would they do that?  Won't this just create competition for MorphLabs?!"  However, once I mulled it over, I realized that if they structure things right, it could be quite beneficial to MorphLabs.  What if these Morph platform deployments simply became new pools of servers to which Morph apps could be deployed?  Viewed that way, it actually sounds quite clever.  I'm almost tempted to attend the webinar, even though it has no direct relevance to me. :)