Posts Tagged ‘Groovy’

Groovy CPE

I’ve been working quite a lot on a TR069 AutoConfigurationServer. As part of the prototyping I created a client emulator to more quickly and easily test out different parts of the TR069 spec. I called the program GroovyCPE and it can be found on Google Code hosting. Hopefully it will be useful for others in initial bringup of TR069 servers, regression testing and performance testing. The code written in Groovy and it is licensed under the GPLv3.

The TR069 schemas which can be found at http://www.broadband-forum.org/cwmp.php define the communication. Unfortunately the CWMProtocol uses ancient technology – namely XML-RPC. One can find old libraries for XML-RPC on the web, but they look old and crusty. We decided to go with JAXB ( https://jaxb.dev.java.net ) to get Java classes from the schemas. However, JAXB doesn’t seem to handle the old XML-RPC ideas perfectly, so we have to apply some band-aid (more on the server side than on the client side, though). I’ll blog about this separately.

To get the JAXB processing to work at all I have deleted fixed="1" from the soapenv:mustUnderstand attributes.

The HTTP communication of GroovyCPE is done with the help of the Apache HttpComponents v3 which is a pretty OK library for HTTP communication.

The initial configuration content in testfiles/parameters_tg784/get*.txt is from a Thomson TG784 box.

GroovyCPE is built around a central store of the parameters it reads in. And as much as possible it uses the configuration parameters it self – eg. for the ManagementServer URL and the PeriodicInformInterval.

What it can do:

• Immediately send Inform messages with all event types
• Run a thread that sends scheduled Inform messages according to the PeriodicInformInterval
• Listen for connection requests on the ConnectionRequestURL (and send an Inform if requested
• Accept a DownloadRequest and initiate an HTTP download session according to the contents
• Respond to GetParameter{Names,Values,Attributes} requests.
• Accept SetParameter{Values,Attributes} and set the values
• Accept AddObject requests and add objects (but only if the object layout is known from the configuration parameters)

I don’t have any immediate plans for improvements to GroovyCPE. At some point I will probably look at fixing the JAXB classes at generation time with a JAXB plugin.

Tags: Grails, Groovy, tr069
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Groovy web shells – ajaxgroovyshell

For the JEE web-app I am currently working on the main audience is power users/admins. So while I can code some usecases as nice seam pages that help the user solve a task, other usecase are difficult. The most difficult are the general batch processes that take the form “select, filter, apply”.

Unix users (who use shell scripts) know that a small amount of programming is effective at solving these problems. So for my web-app I was contemplating how to get something “shell-like” into the project. There are several projects that present a nice AJAX based web interface to the system shell on unix machines. Eg. shellinabox and ajaxterm. And there are several programming languages that seem suited for interacting with a Java app. Eg. Groovy, Jython, or Beanshell.

So I decided to try to combine the interactive groovy shell with an ajax frontend. After looking around quite a lot I found shellinabox which has a nice GPL’ed javascript vt100 front end (I found another here which is LGPL’ed).

After a some weekend studies of shellinabox I could make a prototype with the vt100.js of shellabox and the nice little python webserver of ajaxterm. With a little more hacking I was able to hook up the groovyshell as a web-app through a java servlet. The interactive performance sucked, because of some weirdness in standard java.io.PipedInput/OutputStream classes, but fortunately I was not the first with that problem so with some small hacks to the replacement classes from LiveGraph the interactivity became tolerable.

From this working state there is actually still quite a bit of work to have something that I can deploy on a customer production server. But when Guillaume Laforge announced his cool little app “GroovyWebConsole” to run a groovyshell on the Google AppEngine I figured that I might as well upload what I had and announce it as well. Here is the announcement I sent to groovy-users

I have made a similar app to administer a JEE app I’m doing. It is
similar but is stateful and uses a vt100 interpreter in javascript (from
shellinabox).

You can find it here

http://code.google.com/p/ajaxgroovyshell

It is mostly a prototype – to be really useful for me I need to add

1) Access control
2) A way to paste text from the system (a pop-up textarea?)
3) Proper sessions
4) A robust way to handle threads
5) Syntax highlighting?
6) Better tab completion in GroovyShell (more like ipython)
Unfortunately it won’t run on the Google AppServer since I need a thread
for the GroovyShell.

Best
Anders

Since then I have noticed several java server projects that have some kind of console facility. But not as an ajax webpage (yet). I have suggested it a couple of places (like for Hudson, and for FRESH).

Tags: AJAX, Groovy, JEE
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