Wednesday, February 27, 2013

Vaadin add-on Timeline vs Vaadin Charts add-on comparison


For a recent project I had to evaluate the Vaadin Charts and Timeline add-ons for their capabilities.

- Vaadin 7.0.1
- Vaadin Charts 1.0.0
- Vaadin Timeline which is included in Vaadin Charts since Vaadin 7.0

- Be able to see data for 90 days, and the same data but then per week (same graph, just other view).
- Be able to click on a bar and perform some action like retrieving other data based on the selected bar.
- Customizable three code coloring stacked bars.
- Display more details when hovering over a bar.



This type of graph is very flexible and elaborate in the ways it can display data. It has a "selection bar" below the actual graph so you can determine the values being displayed in the graph above it. See below for a screenshot:

You can try it out yourself in an online demo here and here.


- The graph is scrollable thus no worries about the bars/lines getting too close to each-other.
- You can zoom in and out, also with your mouse.
- Different charts (graph modes) provided by default, changeable in one click: line, bar and scatter.
- A quick zoom per period (1d, 5d, 1w, 5m etc).


- Can't attach any action to clicking on a bar. What you can do is react on the area selected with the selection bar, so a work-around might be to have the user select exactly one bar to mimic a kind of "clicking" on that bar. And then take the appropriate action.
- You can only show days on the x-axis it seems. You can't show a bar per week for example (thus one bar representing 1 week). A work-around might be to create your own Zoom period for 1 week, which is quite easy to do.
- Currently as of this writing there are at least two bugs regarding hovering: the timeline moves down a few pixels when hovering for the first time, and the stacked bars have a hovering problem.


- Can you also add an hover-over tooltip to the bars?

This type of graph does not have the fancy zooming possibilities, but has more possibilities regarding customization and reacting to events. See below screenshot for an example:

You can try it out yourself here.


- The bars are clickable and that event can be handled, indicating the x and y of the item clicked.
- The graph is more customizable; for example the numbers in the bars can be removed.
- Different values (like week number) on the x-axis is probably possible (still out for investigating).
- All data is always visible in the current view.
- Customizable hover-over tooltip.
- Does not have the two (smaller) timeline bugs.


- No horizontal scrollbar or similar, thus for example showing 90 days looks quite "cramped", see the above screenshot. When making the browser smaller, day numbers start to overlap. Do-able, but not optimal. A horizontal scrollbar would be great!
- No space for showing a full date at the bottom. As a work-around the actual date could be added to the tooltip when hovering over a bar (in the screenshot it only says 26).
- No zooming.
- No out-of-the-box other graph modes (i.e like in the Timeline those are provided with it always).


For the project we chose the chart because it is a bit more customizable and the ability to click on a bar and do something with that event was most important requirement.

What's crap about my new Dell Precision M4700 laptop (+ the few good things)

Just got my new Dell Precision M4700 laptop in, which is the top model of their range for 15" screens.
My last laptop was also a Dell Precision, the M4400. Having looked around to see if there's another brand I'd rather take, I still came to the conclusion that a Dell seems to be the best fit for heavy development.

So online I ordered it, with changing the default low 4G or 8G RAM to a more reasonable 16G. That's the first place where I noticed they are really overcharging for the additional RAM: 200 euro (about 261 dollars) for having put in 16G of RAM, while if you buy it seperately it's only about 100 euro. But since I don't like messing around with a brand new laptop (mainly because of warranty) I decided to pay the extra.

Here's a list of pros and cons of the laptop after using it for a few weeks:

- The power plug is straight, so it fits better in a block of power plugs, see the image below:

- It feels sturdy and solid.

- The power cord is still quite short. Why not just add 1 meter more?
- The plug that goes into the laptop is straight and at the back. Lots of times when you've got the laptop on your lap it will just fall out. Much better solution: an angled plug and plug it in on the side of the laptop.
- The keyboard has a numeric keypad. Why would you need that on a laptop? How often will data entry people use such a high end laptop? And it forces me to sit more to the left of the keyboard to be able to type... And I know I'll never ever use that numeric keypad... See image below:

- The Page Up and Page Down are placed at such a weird position. And it feels like they should be the other way around anyway: Page Down left, Page Up right...

- Right after I started it up for the very first time, I wanted to search in the Windows configuration screen. The whole machine just froze, I couldn't do anything else but hard-shutdown the machine via the power button. Ok this might be a Windows problem but still it shouldn't happen within 5 minutes...

- It's really hard to turn off the built-in webcam. Out of the box it will switch on automatically if a video stream comes in (or something like that). This should be the other way around by default. You can only turn it really off via system devices, not via the annoying pre-installed webcam control app.

- For creating a VMWare image of the same Windows 7 Professional OS as on this new laptop, you have to enter the Windows COA product key. And guess where they put it on the laptop? No not on the side or the bottom..... it is inside the battery compartment!! So when you're right in the middle of installation, you have to shutdown the laptop, take out the battery, write down the long key, put the battery in, start it all up again.... Djeezzz!!

- Multiple times I've had now that I put a VMWare guest in suspend-mode and that after that the light of the harddisk stays on "forever". I can hear it spin too. Even if after that I close the VMWare application, the harddisk keeps on going. When after that I put the laptop to sleep via the power button, it stops spinning. When I then turn it on again, the harddisk directly starts spinning again. In Windows Task Manager I can't find any process that is supposed to be reading or writing. So what is going on? Who is reading and/or writing? Is the disk crappy? After running diagnostics (during bootup) no problems are found. Is VMWare causing it? I can't reproduce it everytime, so can't really make a support call for it. But all 'n all it doesn't give me much confidence in the machine + setup combinatino.... I'm planning on re-installing the whole OS, so no Dell Recovery manager and other Dell software is on it anymore. Hope that makes it more stable...
- When I plug in a headphones cable on the left, my mouse keeps on bumping into the cable.

Well, that about sums up this "rant".... Next time I'll definitely re-consider whether I should purchase a Dell again....

Saturday, February 2, 2013

Lessons learned Spring 3.0 project

Another quick post with some bullet points of lessons learned during my last Spring 3.0 project.
Tools used were:

  • Spring 3.0 (3.1.2 when moving to Hibernate 4)
  • Spring MVC
  • Spring WebFlow 2
  • Spring Batch
  • Spring Agent Framework
  • Hibernate 3.2.6
  • Apache CXF
  • JBehave (Behavior Driven Development)
  • Tiny bit of GXT, which is a Google Web Toolkit extension based on GWT and ExtJS technology. Formally known as Ext GWT, GXT is a Java library for building rich internet applications with the Google Web Toolkit (GWT)
  • JBoss jBPM 5.2.0
  • JBoss Drools 5.3.1
  • Jenkins for CI
  • Crucible for code reviews
  • Jira for issue tracking en sprint user stories and tasks and progress tracking
  • SpringSource Tool Suite 2.9.1 as Eclipse based IDE
  • JUnit 4.8
  • EasyMock 2.5.2, EasyMockSupport
  • Java 6
  • Cargo-itest (introduction here) for integration testing
  • Tomcat 6
  • Oracle SQL Developer (free version)
Besides learning new tools like JBehave an Cargo-itest, below are some things picked up using above tools.

Spring MVC
Had some issues getting REST-like services available, mainly from inexperience, but good to know what's working and what not:

    Response getSomeOtherUrlParams(@PathParam(value = "roleId") final String roleId);
    // Unable to call it, because PathParam is not existing (it's not really part of the path)

    Response getSomeOtherUrlParamsNotAsRequest(@PathParam(value = "roleId") final String roleId);
    // Works

    Response getSomeOtherUrlParamsAsQueryParam(@QueryParam("role") final String roleId);
    // Works, will have clients of this service (like SoapUI) already generate a ?role= parameter

    Response getSomeOtherUrlParamsAsRequestParam(@RequestParam("role") final String roleId);
    // Won't generate a ?role= parameter for clients, the WADL also looks different for this method/parameter

Don't use @FormParam for submitting XML because if the mediatype is text/xml for example, the mapping on the REST method fails because JAXRS expects HTML (default if not specified at the service definition).
So suppose the service is defined as:

    Response sendMessage(@PathParam(value = "messageCode") final String messageCode, 
                                         @FormParam("moduleName") String moduleName,
                                         @FormParam("userId") String userId, 
                                         final MessageContentsRequest messageContents);

When invoking the above method by POSTing to 


with as POST body parameters moduleName and userId + the MessageContentsRequest XML, that gives the following error in the log:

2013-01-05 11:24:38,491 WARN  [http-8890-1] JAXRSUtils#processFormParam - An application/x-www-form-urlencoded form request is expected but the request media type is text/xml;charset=UTF-8. Consider removing @FormParam annotations.
2013-01-05 11:24:38,493 WARN  [http-8890-1] WebApplicationExceptionMapper#toResponse - WebApplicationException has been caught : no cause is available

The same error occurs when invoking: ..../send/?moduleName=abc&userId=ttl  (so adding them as POST URL name/value parameters).

So make sure you use in that case:

    Response sendMessage(@PathParam(value = "messageCode") final String message ode, 
                                         @QueryParam("moduleName") String moduleName,
                                         @QueryParam("userId") String userId, 
                                         final MessageContentsRequest messageContents);

The moduleName and userId can then be passed in via the POST URL name/value parameters.

Use replayAll() and verifyAll() instead of replay(mock) and verify(mock) for each mock seperately. Requires extending EasyMockSupport.

SQL Developer
The free SQL Developer can't export clob column values. Nor can it import clob values larger than 4K.