The Toronto Java Users Group is back for its fourth great year. Things are going well, we have a nice steady group of regulars. We still meet at the Free Times Cafe, and the meetings have a nice social aspect. Presentations are short and sweet, and we try to avoid blatant product pitches.
If you’re into Java, and you’re in the GTA, you should totally join us. Third Thursday of each month, Free Times Cafe, 7pm start.
Check out the TJUG site for more info!
This is a disturbing thread from my email (names have been changed to protect the innocent):
From: John Smith
To: DanDan,
I got your email from your blog, linked from the Toronto Java Users Group.
Wondering if you or any of your friends / contacts may be interested in
Java Developer opportunities in downtown Toronto?Do you have any contacts you could send my way or forward this email to?
Thank you,
John Smith
416−555−1212
My very snarky, sarcastic reply:
From: Dan
To: John SmithIf I sell you my friends, do I get a cut of your commission?
John seemed to miss my snark and replied with a serious reply:
From: John Smith
To: DanDan,
I’m definitively open to that.
Just to be completely honest and open you should know, I’m only starting out and am a sourcer for another Recruiter. Which means I’ll get about $400 for a successful placement that the Recruiter gets $5000 for.
But of course, out of my $400, you can get a piece, and hopefully in time when I become a full-fledged Recruiter our relationship will continue to produce.
John
You learn something new every day.
I am extremely disappointed with this product. It has serious design and quality flaws.
I’ve been investigating putting some Insteon devices in my house to control my lights and appliances, so I ordered a few samples. I ordered a wire-in dimmer (2876DB), a 2-wire wire-in dimmer kit (2474D), a powerline modem/computer interface (2413U) and the above-mentioned plug-in lamp module.
My first hint of the quality problems with this lamp module came when I first plugged a lamp into it. The plug just didn’t fit right. It seemed to bottom out long before it was completely inserted. Complete insertion was possible with a bit of wiggling and force, but then the plug didn’t make a proper connection. The plug only connected properly when it was inserted about 2/3 of the way, which is not a safe condition.
I took the device apart to investigate (luckily this was easy — just remove four screws on the back). I was quite surprised by what I found! The reason the plug didn’t fit was clear — the screws holding the contacts to the device’s case were interfering with the plug! Check it out:
This is a totally puzzling design flaw. Didn’t they ever try actually inserting a plug? How could this product even get past a prototype stage? It’s possible that my unit is defective or built incorrectly, but I don’t see any other way it could be put together.
When I showed it to my friend Andrew, he noticed another critical flaw. The aluminum heatsink for the dimmer triac inside could touch one or both output terminals, causing a short circuit. This could easily happen if the device was dropped or shaken when powered on, and it would definitely cause the device to be destroyed. I got out a multimeter and tested it, putting one probe on the output terminal and the other on the heat sink, and a slight press on the heat sink caused a short circuit. Take a look:
I added a small piece of high-temperature Kapton tape to the underside of the heat sink so I could feel better about this device and reassembled it. I’ll probably use it, but I certainly won’t buy another one. It’s total junk. For $50, I didn’t expect excellent quality, but I at least expected to get something safe and reliable.
Hopefully my other Insteon devices will be better.
About five years ago, I wrote a script to scrape the website of Rotate This and republish their concert ticket listing as an RSS feed. Every six hours for five years I’ve hit their site and updated my database. The RSS feed has quite a few users, using FeedBurner, Google Reader, Bloglines and a few other miscellaneous RSS viewers. It’s one of the most frequently hit pages on my site.
I wanted to try out the new Google AppEngine service, and was looking for a simple project, so I figured I could port my little scraper. It seemed like perfect fit.
Google AppEngine is a unique application hosting service. It’s not really classical web hosting, and it’s not really a virtual server. You generate a Java web application, bundle it as a .war file, and deploy it to AppEngine. Google’s magic voodoo makes sure that your app is hosted on at least two servers, that it will scale automatically for load, that it will start up quickly, and that it will always have access to its data. There are some restrictions, however: no request to your app can take longer than a few seconds to process, and there are strict size limits for data storage access and request/response size. It can’t start threads, it can’t access the disk, it can’t use too much memory.
There is no real “backend” access to your app either; all access must happen though a URL. The Cron service simply calls a specified URL within your application on regular intervals.
A big advantage to AppEngine is that their basic service is free. The quotas for requests, data transfer and CPU time under the free service level are very high. Anything that exceeded them I would call a very successful app — it is unlikely I will ever have to buy more capacity. The free service includes over a million requests and a gigabyte of data transfer per day.
I spent a couple of days working on it — AppEngine was easy to learn but had a few quirks. My older code was in Perl (the scraper) and PHP (the RSS generator) using MySQL as a backend. The AppEngine code is all Java, using Google’s datastore through Java Data Objects. I had never used JDO before, so there was a bit of a learning curve there. Everything else was straight forward, using the URL Fetch service to get the Rotate This ticket page, and using the Cron to schedule the scrape every six hours.
On the output side I was able to take advantage of the rich Java ecosystem, using ROME to generate the RSS feed, and using ICal4J to generate the new iCal feed that I was adding on. Both worked fine on AppEngine’s restricted Java runtime.
So, here are the links, give it a try!
Rotate This Tickets RSS Feed: http://rotatethisrss.appspot.com
Rotate This Tickets iCal Feed: http://rotatethisrss.appspot.com/ical
Let me know how it goes!
p.s. I redirected the old link to AppEngine — if you were using this before, you shouldn’t have to change anything.
My Roomba 560 was making clunking noises as it drove around… I think it was the safety clutch somewhere in the brushes drivetrain. I took out the brushes and cleaned as much cat hair as possible, but there was some jammed in one of the square drives in the side of the brush housing. I couldn’t get that out, so I decided to take apart the Roomba and its brush module and see what was going on.
Disassembly was easy. There are quite a few different-sized screws, so keep them organized… but take it easy, don’t force anything, and you should have no trouble getting into the gears. I lubricated things with some Tri-Flow synthetic grease (which is safe for plastic) and put it back together.
Here’s a little video I made of the process:
Watch it in HD for best results! Note the screw that got away when I pulled off the spinning brush at the front… I found it again, but take some precautions so this doesn’t happen to you as well.
A few days ago, I got a sudden feeling that I was on too many social networks and my information was spread too far out of my control on the internet. I was also reading a lot about Facebook’s privacy problems and their erosion of user controls in order to better monetize their information 1, 2, 3. During the process of quitting Facebook, the site showed me pictures of my friends, and told me that they would miss me. It said “your 153 friends won’t be able to communicate with you anymore!” Scary.
I was also regularly using Foursquare, which is a social networking application that lets you “check in” at various physical locations and see who else is there. If you check in to a place more than anyone else, you become “Mayor,” and if you check in at the right sequence or number of places, you can win “badges.” This was fun for a while, I was Mayor of several places, and I had lots of badges, but I didn’t feel I was getting anything out of it, and Foursquare was getting a lot of valuable information. I forgot to “check in” at work for a few days, and when I realized this, it was time to finish with Foursquare.
I also had several near-dormant accounts with Instant Message services. I had an MSN account, a Yahoo account, an AIM account and a Google Talk account. I’m on LinkedIn, and Twitter, Last.Fm, YouTube and Vimeo, and who knows what other services I don’t remember at this point. Too many.
I have been using Passpack to organize my online passwords, which I’ve been happy with. They have a very strong security policy, a sane privacy policy, and I pay for service, which feels a bit more safe as well. As I’ve been changing passwords and entering them into Passpack, it has given me a view of just how many accounts I have! I have over 40 entered so far, and there are a lot more to go.
So, I’ve been cleaning this up a bit. I’ve decided that I want to focus on my blog/website, my Twitter, and my Google Talk. I’m going to share videos with YouTube, at least until Vimeo improves their iPhone support. Almost everything else, I’m going to get rid of. If you happened to talk to me on one of the services I’ve deleted, you can always find me here. Check the “Contact Info” box on my blog, or just call me on the phone.
Removed so far:
… and more to come.
So far, this feels pretty good! I’ve been focusing on services that feel less evil, don’t try to collect as much personally identifying information, and who are at least more subtle about their attempts to monetize me.
At work we have a KVM switch for our test rack, the very nice MasterConsole IP 116, from Raritan. The switch has a competent web user interface, but no published automation API. I guess it’s reasonable to assume that nobody would want to automate a KVM switch, but once in a while, you might find a need.
We have a large screen hooked into the switch’s video output, and we want to switch which input we’re watching on a fairly regular basis. One click access would be ideal, but the web UI forces you to log in, select the desired input from a dropdown menu, and click a “switch input” button.
I wrote a small Groovy script using the HtmlUnit testing framework to automatically navigate the web UI, which was totally painless and didn’t require any reverse engineering.
Check out the script… you might find the concept useful for automating your own interactive-only device.
package com.onestopmedia.kvmcontrol
import com.gargoylesoftware.htmlunit.WebClient
import com.gargoylesoftware.htmlunit.html.*
class KvmControl {
public static main(args) {
def cli = new CliBuilder (usage: "KvmControl")
cli.u(longOpt: "username", "set username", args: 1)
cli.p(longOpt: "password", "set password", args: 1)
cli.i(longOpt: "input", "set input (0-15)", args: 1)
cli.q(longOpt: "query", "query current input only")
cli.h(longOpt: "help", "usage information")
def opt = cli.parse(args)
if (!opt) return
if (opt.h) cli.usage()
def webClient = new WebClient();
def page = webClient.getPage("http://192.168.7.3/auth.asp") as HtmlPage
def loginForm = page.getForms().get(0) as HtmlForm
loginForm.getInputByName("login").setValueAttribute(opt.u)
loginForm.getInputByName("password").setValueAttribute(opt.p)
def button = loginForm.getInputByName("action_login") as HtmlImageInput
def page2 = button.click() as HtmlPage
def dataFrame = page2.getFrameByName("data")
.getEnclosedPage() as HtmlPage
def selectForm = dataFrame.getForms().get(0) as HtmlForm
def inputSelect = selectForm.getSelectByName("ECG_kvm_active_port")
as HtmlSelect
if (opt.q) {
def currentlySelected = inputSelect.getSelectedOptions()[0] as HtmlOption
println ("currently selected: "+currentlySelected.getText()
+" ["+currentlySelected.getValueAttribute()+"]")
} else {
inputSelect.setSelectedAttribute(opt.i,true) as HtmlPage
def switchButton = selectForm.getInputByName("action_switch")
def page3 = switchButton.click() as HtmlPage;
}
}
}
I can see 62 different access points from my apartment. Only two or three are carrier-grade hardware, the rest are just people’s home routers. I can only see three that are on 5GHz though, and one of those is mine. If you’re in a really WiFi-dense area (ie, anywhere downtown) you will get quite a bit of benefit from a 5GHz (802.11n) upgrade, at least for a while…
Chrome for OS X is lacking a bookmark export feature. I’m sure it will have one in the future, but it doesn’t have it yet. It will happily import your mozilla bookmarks and let you get started using the browser, but eventually you will notice that your bookmarks are locked in. It only recently got a very rudimentary bookmark manager in the latest nightly builds, but there is still no export.
The Chrome bookmark file in OS X is a simple JSON database, so I whipped up a quick tool in Groovy to do the export. This was really a single-use project but I figured I would post the source and binaries in case someone else needs it.
Usage: java -jar ChromeExport.jar > mybookmarks.html
By default it will find the current user’s “Default” Chrome profile. Since Chrome doesn’t seem to have any UI for managing profiles, I don’t see why you’d have a different one.
Requirements to build/run:
* Groovy 1.6+
* Commons-Lang (for the StringEscapeUtils)
* json-simple (for the JSON parser)
Here is a link to the source: ChromeExport.groovy
Here is a link to the fully bundled binary (which probably breaks somebody’s license agreement somewhere, but compliance is not worth the annoyance): ChromeExport.jar
Enjoy! Let me know what you think, or if it works for you!
