I'm split between the advantages of developing Java (non-commercial) webapps and implementing to something similar to Aptana or Google cloud, or simply using a Slice Host account. Tomcat or Jetty and MySQL are actually my only large needs. Aptana and Google Application Engine include some awesome Eclipse deployment options, but does scalability really matter with no large users list for that applications?
Also, both Aptana and Google Application Engine appear to stay infant stages, so I am wondering if you will see a lot of limitations, for small-time development. Anybody have knowledge about these?
I can not talk to Aptana but Google Application Engine is really a significantly different development experience from what you'll receive with something similar to Slicehost. It scales in a different way (i.e. you have the potential of handling much bigger loads) but it is also completely different than running your personal web application server (e.g. Glassfish, Tomcat, JBoss, etc.) and coding using "standard" Java tools.
With Slicehost or any located solution it's not hard to setup your personal development atmosphere in your area which exactly imitates what you will be running about the server. Same software, same VM, possibly even exactly the same version of Linux. You can even move to another host but still have the ability to setup that same atmosphere.
With Google Application Engine you will find yourself building with an emulator (you do not really run BigTable in your area) so there isn't a face to face correspondence involving the atmosphere which about the server. There is no alternative spot to proceed to but still be running within the same atmosphere either. Also, some possibly most of the popular Java frameworks you may use for any web application development will either not work on all (e.g. ) or won't exercise-of-the-box (see for more particulars).
I am not lower about the Application Engine, actually, I believe it is awesome. When the interest in your applications is comparatively low and for that reason you are not looking for the large scaling needs, your visitors are not too low that you simply fit easily inside the free allowance at Google i quickly would most likely lean towards a located solution like Slicehost rather.
I personally use slicehost and i'm pleased with the end result to date. It is easy to change your slice (I needed to get it done once already) and it is simple to rollback to some backup from the slice (I needed to do this once too). I'm hosting Tomcat and MySQL.
Keep in mind, Google Application Engine doesn't provide you with a full JRE. You can't spawn threads directly, for instance. Also, I've discovered the GAE datastore performance is simply too slow -- I encounter timeout exceptions constantly. In sum, it's not a genuine application hosting solution. You need to heavily tailor the application to really make it operate on GAE.
I'd suggest using Amazon . com Web Services. You receive the energy from the cloud without any restrictions for your application, unlike Application Engine.