Saturday, 28 March 2009

EIP Shapes for OpenOffice Draw

If you’ve read the excellent Enterprise Integration Patterns (EIP) book by Gregor Hohpe and Bobby Woolf, you may also know that free VISIO stencils are available for the EIP shapes, from the download page.

This is great for those who have a copy of VISIO (or whose employer pays for a copy), but for those of us who don’t want to pay however many hundreds of dollars Microsoft wants for VISIO these days, an alternative (especially a free one) is always welcome.  OpenOffice (OOo) Draw, though hardly as functional or attractive as VISIO, is both free and good enough for many diagrams.

So I decided to see if I could create a set of OOo Draw shapes from the VISIO stencil, and see whether Draw could be practical for integration diagramming.  In short, I succeeded in converting the stencil, and I think Draw is just about good enough. For those not interested in the background, I’ve made the material freely available from this page on my website, so just go ahead and download/install.  Otherwise, read on.

Exporting the VISIO Shapes

One way to get shape data into Draw is via SVG. So I started with the VISIO shapes, freely downloadable from the EIP site, and as I use VISIO at work I was able to load up the stencil and export it as SVG. 

You need to install an OpenOffice extension for importing SVG. I’m using OOo 3.0: the extension installed without incident and the import was straightforward. I was surprised at how good the resulting shapes looked in Draw.  Each shape is composed of drawing primitives, so you need to select and group them to create a shape you can place and move easily. I’ve done this for all the shapes in the download.

So now we have the shapes, where can we put them to make them easily reusable?  In Draw, there’s no stencil feature as such: the only option is the Gallery:


The Gallery

The gallery feature in Draw isn’t very appealing, initially. When you first install OOo, the gallery contains some spectacularly awful materials: nasty backgrounds and bullets which I cannot imagine ever wanting to use, and it even contains some pointless sound-clips that surely only a 5-year old might use (and only then if they were desperate). The shapes and graphics are reminiscent of shareware software from the Windows 95 era.  And what is the point of the built-in media player?  Why can’t OpenOffice grow up?  It’s so very close to being excellent in many respects: things like this just make it look silly and dated.

Anyway, back to the gallery feature. The one saving grace of this feature is that you can create new gallery themes and add your own shapes to them. To do this, create a new theme, give it a name and then drag your shapes into it.  Note that when you drag/drop your shape you must hold down the mouse button and pause a second or two before dragging: this pause changes the drag-mode from a simple shape move to the required move/copy.

I’ve done this for all the EIP shapes, creating an EIP gallery theme:


Sharing the EIP Theme

Unfortunately, Draw doesn’t implement a theme export facility so to share this new theme with others requires some irritating file copying.  The contents of the Gallery are stored in your profile (or home) folder. On Windows this is likely to be:

C:\Documents and Settings\<user>\Application Data\\3\user\gallery

On Unix/Linux, check your home folder. There are several file types in here and (unusually for OOo) they are binary, not XML. This makes it difficult to reverse-engineer their purpose and relationship but fortunately it doesn’t seem to be necessary to understand fully what’s going on. The key thing to note is that the numbers in the file names bind together related files.  When you create a new theme, a new set of files appears to be created.

For the EIP theme I have manually renamed the files to use numbers which I hope won’t clash with any existing gallery files you may have.  Check the zip contents before you extract the files into your OOo folder and if you have existing files with the same name, simply rename the files in my zip to be unique in your environment. 

The Result

I think the result is pretty good.  As a test, I have (partially) reproduced the diagram from the end-cover of the EIP book in a Draw file (.odg) which is included in the download zip:


I hope this may be some use to other folk.  Download from this page.

Friday, 27 March 2009

OpenESB and BPEL

Thanks to the folks who commented on yesterday’s post I have managed to overcome the assign problem and of course the answer was very simple: I had an inconsistent set of components installed in NetBeans and GlassFish.  I was using NB 6.5 together with components downloaded from the OpenESB site. 

The best solution is simply to download the complete NetBeans/GlassFish/OpenESB combination from the OpenESB downloads page and work with that. On the download page the top section contains the GA (stable) GlassFish ESB / NetBeans combination, and the nightly build of the latest (unstable) additional components (i.e. binding components, service engines etc.) which match this GA release.

The next major section on the page contains the GlassFish ESB v2.1 downloads (milestone 1 at the time of writing), which are not yet considered stable. I grabbed the 2.1 release, plus the HL7 BC (and NB design-time modules) from here.  Installation was completely pain-free.  I particularly liked the way the additional components are packaged as a jar-based installer – very nicely done. 

Because the main package is a GlassFish ESB bundle, it installs by default to a non-standard path: C:\GlassFishESB. Everything is installed under this directory, including the configuration files for NetBeans, which would normally be placed in your home directory (under .netbeans). Presumably this is done to allow parallel installation with a stable NetBeans/GF without either interfering with the other. What this means, of course, is that all your preferences (editor settings etc.) are not transferred. This is easily fixed, manually, by copying over the stuff from: C:\Documents and Settings\<user>\.netbeans\6.5\config\Editors to C:\GlassFishESB\.netbeans\glassfishesb\config\Editors

Anyway, back to the BPEL issue.  A clean rebuild of everything was sufficient: the CA deployed to GF, and it ran fine.  I used Hermes JMS and watched the test messages arrive on the queue. Now I can push ahead and explore more of OpenESB and BPEL.

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Thursday, 26 March 2009

Problem with OpenESB BPEL assign

After far too many cycles staring at code, building, deploying, debugging and undeploying a pretty simple composite application, the damn BPEL assign activity still causes selectionFailure at runtime.

The BPEL is trivial, and the BPEL copy elements for optional elements in the source schema are marked with the ignoreMissingFromData attribute.  I have rebuilt everything from scratch.  I know the redeployments are successful because the error reports points to the correct line following an edit and I can use the BPEL debugger to step through the assign, eventually failing on the optional element.

I was given the hint about the ignoreMissingFromData attribute by Michael Czapski, in a blog comment.  Googling around for more help, I came across a few other postings, and discovered that the attribute could be placed at the process level or at the individual copy activity level. Jeff Sexton also has a nice post on the assign issue.

In Michael’s tutorial he does in fact place the attribute at the process level (see p.95 of the PDF document which accompanies his tutorial). Placing it at the process level is not very attractive because it will mask the absence of mandatory fields.

When placed at the copy element level, it seems to fail. Here’s the error I see, as output in the GlassFish console window:

BPCOR-6151:The process instance has been terminated because a fault was not handled; Fault Name is {}selectionFailure; Fault Data is null
com.sun.jbi.engine.bpel.core.bpel.exception.StandardException: I18N: BPCOR-3023: Selection Failure occurred in BPEL({}bpHL7Processor) at line 28!
BPCOR-6129:Line Number is 26
BPCOR-6130:Activity Name is Assign1

Note the line numbers in the above report: the first of these (line 28) is where the selection failure actually occurred, line 26 is the opening tag of the enclosing assign activity element.  Here’s a shot of the source so you can see the corresponding line numbers. I placed all the optional elements together at the start of the assign:


So why doesn’t this work? Is this a bug? Perhaps I’ve run into something which only works in the JavaCAPS product and not in OpenESB?  Shame.

Another unfortunate discovery is that the OpenESB UI in NetBeans 6.5 doesn’t seem to support adding the ignoreMissingFromData at the process level.  In Michael’s PDF he selects the top-level BPEL process scope and uses the property panel to set this attribute.  It doesn’t appear to exist in NB 6.5. In the shot below I’ve tried to capture the same UI as in Michael’s tutorial:


Note there’s nothing below the ‘Documentation’ entry: presumably this is additional UI support which you get in the commercial JCAPS product. I’m not that concerned with the missing UI, as long as I can add the attribute in the XML source.  So I edited the BPEL XML, using Michael’s tutorial source as a guide. It’s easy to add the process-level attribute; only the namespace prefix had to be changed:

<?xml version="1.0" encoding="UTF-8"?>

So another clean/build/deploy and … it still didn’t work. So now I’m stuck, and I hate being stuck. It’s almost enough to put me off the product.

The impression I get is that BPEL is great for very simple maps and transforms, but anything complex quickly becomes awkward. I haven’t gone beyond ‘simple’ so far, so I’m getting a little concerned. The pretty visual tools and NetBeans integration are cool, but the complexity overhead seems high. It reminds me of Microsoft’s BizTalk product from a few years back – a lot of fiddly config, and not being able to ‘see the wood for the trees’. 

But I want to persevere with OpenESB: something about this product suggests that you need to reach a certain level of enlightenment, after which everything becomes clear and the benefits outweigh the overheads. I’m just not there yet.

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Wednesday, 18 March 2009

DropBox again

The previous post elicited a comment from Andy at CloudBerry Lab:

I am a developer of another online backup product powered by Amazon S3 that we are going to release to beta soon. I would appreciate if you take a look and may be post a review on your blog.

Well I did take a look, but the CloudBerry product isn’t really what I’m looking for.  If all you want/need is a Windows-only client for accessing your S3 buckets directly and copying/moving content, then this product might well be just right.  But it doesn’t really compete with DropBox or JungleDisk.  Andy: if your product were closer to DropBox, and cross-platform, then I would have reviewed it.  As it is, I can’t pass judgement.

If you have time to plough through a very long blog thread, check out Jeremy Zawodny’s excellent piece on Amazon S3 tools. The discussion thread contains links to most (maybe all) the tools out there.

I’ve also been reading the DropBox forums. It’s good to see plenty of other people have requested features I miss (e.g. ability to configure DB to ignore certain file patterns).  There is an upcoming features wiki page which lists some things coming ‘soon’.  Nothing on using your own S3 space though.

Monday, 16 March 2009

JungleDisk and DropBox

There are quite a few network-drive products out there competing for our attention these days.  I’ve tried quite a few (including and SkyDrive), but narrowed the choice down to the two which seem the best: JungleDisk and DropBox.

JungleDisk attracts me mostly because I can use my existing Amazon S3 storage behind the JungleDisk tool and pay only for the space I actually use. (Note, JD now also uses RackSpace CloudFiles, which actually looks even better than S3).  DropBox is free for 2GB, then a hefty 99 USD annually, for 50GB.  Round one to JungleDisk, in my view.

Then we come to the user-interface. Both tools integrate with Windows and Linux, JD using drive mapping to expose the storage and DropBox using a special folder inside My Documents, with icon overlays to indicate file status.  Both support drag/drop access and run a small tray-resident UI application.

But DropBox is just so, so much nicer to use than JD in the everyday Windows context.  It feels better integrated and the UI seems cleaner.  Other folk have blogged about this difference and I must concur – DropBox has the edge.

Now to the subject which prompted this post in the first place. Neither of these products appears to handle proxy servers particularly well, especially when switching between proxy / no-proxy.  If I restart Windows and forget to switch off the proxy in JD, here’s the mess I’m greeted with when Windows starts:


Yuk. Can’t it simply notice that the proxy isn’t responding, log the fact / decorate the tray icon, and leave it for me to sort out?  It gets worse: if I click on the links (for more information) look what I get:


Is this really what they want the user to see?  This is awful.

DropBox is slightly better, but still doesn’t work properly if I leave the proxy on, and restart. No nasty dialogs, but the network connection isn’t resolved, even if I set it to ‘auto-detect proxy settings’ which according to the DropBox site should use the IE settings. Why can’t these tools auto-detect proxies properly?

DropBox files are cached on the local machine which means if the network is down I can still work on all my files locally, and re-sync when I next connect.  JungleDisk does cache your files, but in a pretty inaccessible way in your profile.  The path will be something like C:\Documents and Settings\<user>\Application Data\JungleDisk\cache\e9998872111157539d8880eca4456345-default

Another good feature of DropBox which isn’t available in JungleDisk is sharing files and folders: in JD, everything is private.

DropBox gets so many things right. The one and only feature I want from JungleDisk is the S3 / CloudFiles backing store. Obviously, the DropBox business model is built around the 99 USD annual charge so I don’t know whether this can/will ever happen.

Wednesday, 11 March 2009

OpenESB and HL7

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As well as looking at Apache Camel for healthcare integration, I have also been spending time with Sun’s OpenESB product.  OpenESB is the open-source counterpart of the Java CAPS product, a mature and well-supported Enterprise Service Bus (ESB) built on the Java Business Integration (JBI) standard.

OpenESB is delivered along with the GlassFish application server (v2) when you install the SOA extensions to the NetBeans IDE.

Michael Czapski of Sun is an excellent source of information on healthcare-related application of the CAPS / OpenESB product line. He has created a really substantial demonstration project based on a healthcare integration scenario. His blog entry and the associated downloads (and screencast) are well worth getting hold of.  The screencast and writeup are based on Java CAPS, the commercial product which provides a few nice UI improvements and I believe some additional tools which the OpenESB product does not have.

I decided to go through Michael’s complete tutorial, using NetBeans 6.5 and the bundled OpenESB / GlassFish combination, building the solution and making notes as I went along. I’ll put the source code for the NetBeans (6.5) and OpenESB project group up on a publically available Assembla Subversion space (URL to follow), in the hope they may be useful to others who want to use OpenESB to do a similar thing.

As already mentioned, the differences between Java CAPS and OpenESB are superficially small, so if you are already familiar with one or other product you probably only need Michael’s notes and material. However, if you’re relatively new to OpenESB (as I am), there are a few places where the absence of JavaCAPS tooling means you need to know what you’re doing to patch-up the OpenESB solution.

Getting Started

My first big lesson was getting a correct / compatible set of NB plugins and libraries installed. The zip archive provided by Michael appears to contain everything you need, including the XSDs, NB plugins and encoder libraries. As the article was published very recently, I assumed these were the latest versions so tried to configure my NB 6.5 instance using these.

I followed the instructions for installing the encoder library (first uninstalling the existing one), then installing the NB plugins. However, the plugin installation just wouldn’t go ahead:


I tried various combinations but in the end had to uninstall GlassFish v2 and run the NB installer again to reinstall GF plus the OpenESB bits. Fortunately, this is actually quite a quick process, and puts everything back as it was.

I won’t go through all my subsequent false-starts, but simply tell you to download a matched set of the latest versions from this location:

The components here should all be compatible. It really is best that you download and install these yourself, so I won’t put them in the Assembla SVN space.

Doing without the Java CAPS Wizards

The most obvious differences when watching the screencast are the degree to which the commercial product contains wizard steps and conveniences for generating all the configuration items. Reasonable enough I think, and so far I have been able to complete every step using OpenESB and NetBeans 6.5.

When creating the concrete WSDL definitions with the HL7 bindings, the wizards in the Java CAPS product (seen in Michael’s screencast) do make the whole process slightly simpler. But if you take a little time to understand what these wizards are actually doing in the generated WSDL, it’s not too hard to complete the steps manually.  That’s easy to say now, but I should ‘fess-up and admit that it took me a little while to spot what I hadn’t done, a couple of times.

For example, once I’d completed the HL7Consumer_CA_A01_A03Delim_HL7In WSDL (sorry Michael, I’m not a big fan of your naming convention!), I simply couldn’t add it to the Composite Application design surface: the tutorial document instructions didn’t appear to work. I could see the WSDL in the list of available WSDLs and select it – but could not add it to the canvas, and couldn’t see any error message to tell me why.

After a cup of tea and a biscuit and a bit of careful thought, I realised why. The HL7 protocol properties were completely missing from the port declaration in the Services section.  It’s easy to fix this, using the context menu commands:


Then edit the properties in the property grids. Of course, in the JavaCAPS product the wizards prompt you for these properties and create the related WSDL bits behind the scenes.  I don’t like depending on wizards. Fortunately the NetBeans tooling gives you just enough convenient UI to hide the underlying cruft, but also lets you work at the XML / source level and see what’s going on down there.

That’s probably enough for this post.  There’s so much more to write but I need to knock it into shape before I publish.