DDevelopment & Design

Deploy WSDL file as OSGI Bundle in Apache Karaf

Introduction

WSDL file describes webservices. Java classes are often generated from WSDL. For this purpose, we could use command line tools (e. g. wsdl2Java or wsimport) or using maven plugin.

From the other side, we have Apache Karaf which is OSGI container. Karaf has installed by default many deployers for creating OSGi bundles from files, e. g. Blueprint deployer, Spring deployer or War deployer.

It is easy to generate java classes from WSDL file and also to create custom deployer for Karaf, so why do not join these two features?

Installation of WSDL deployer

Source code of my WSDL deployer is provided here. You can download and build it:

mvn clean install

We also need Karaf. I will use the newest version 4.0.5. It could be download from Karaf website. When you download and unpack it, you can run it:

$ cd PUT_PATH_TO_KARAF_DIR_HERE
$ ./bin/karaf
    __ __                  ____      
   / //_/____ __________ _/ __/      
  / ,<  / __ / ___/ __ / /_        
 / /| |/ /_/ / /  / /_/ / __/        
/_/ |_|\__,_/_/   \__,_/_/         

Apache Karaf (4.0.5)

Hit '<tab>' for a list of available commands
and '[cmd] --help' for help on a specific command.
Hit '<ctrl-d>' or type 'system:shutdown' or 'logout' to shutdown Karaf.

karaf@root()>

and install commons-io and wsdl-delpoyer bundles:

karaf@root()> install -s mvn:org.apache.servicemix.bundles/org.apache.servicemix.bundles.commons-io/1.4_3
Bundle ID: 52
karaf@root()> install -s mvn:com.github.alien11689.karaf/wsdl-deployer/1.0.0-SNAPSHOT
Bundle ID: 53

Install WSDL from Karaf shell

I will test deployer using WSDL file named exampleService-2.0.0.wsdl (provided WSDL is similar to this, but has another namespace in types schama for testing purpose):

<?xml version="1.0"?>
<wsdl:definitions
    xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/"
    xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd"
    xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/"
    xmlns:tns="http://Example.org"
    xmlns:sns="http://Example.org/schema"
    xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/08/addressing"
    xmlns:wsp="http://schemas.xmlsoap.org/ws/2004/09/policy"
    xmlns:wsap="http://schemas.xmlsoap.org/ws/2004/08/addressing/policy"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    xmlns:msc="http://schemas.microsoft.com/ws/2005/12/wsdl/contract"
    xmlns:wsaw="http://www.w3.org/2006/05/addressing/wsdl"
    xmlns:soap12="http://schemas.xmlsoap.org/wsdl/soap12/"
    xmlns:wsa10="http://www.w3.org/2005/08/addressing"
    xmlns:wsx="http://schemas.xmlsoap.org/ws/2004/09/mex"
  targetNamespace="http://Example.org"
    xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/">
    <wsdl:types>
        <xsd:schema targetNamespace="http://Example.org/schema" elementFormDefault="qualified" >
            <xsd:element name="Add">
                <xsd:complexType>
                    <xsd:sequence>
                        <xsd:element minOccurs="0" name="a" type="xsd:int" />
                        <xsd:element minOccurs="0" name="b" type="xsd:int" />
                    </xsd:sequence>
                </xsd:complexType>
            </xsd:element>
            <xsd:element name="AddResponse">
                <xsd:complexType>
                    <xsd:sequence>
                        <xsd:element minOccurs="0" name="result" type="xsd:int" />
                    </xsd:sequence>
                </xsd:complexType>
            </xsd:element>
            <xsd:element name="Subtract">
                <xsd:complexType>
                    <xsd:sequence>
                        <xsd:element minOccurs="0" name="a" type="xsd:int" />
                        <xsd:element minOccurs="0" name="b" type="xsd:int" />
                    </xsd:sequence>
                </xsd:complexType>
            </xsd:element>
            <xsd:element name="SubtractResponse">
                <xsd:complexType>
                    <xsd:sequence>
                        <xsd:element minOccurs="0" name="result" type="xsd:int" />
                    </xsd:sequence>
                </xsd:complexType>
            </xsd:element>
        </xsd:schema>
    </wsdl:types>
    <wsdl:message name="ICalculator_Add_InputMessage">
        <wsdl:part name="parameters" element="sns:Add" />
    </wsdl:message>
    <wsdl:message name="ICalculator_Add_OutputMessage">
        <wsdl:part name="parameters" element="sns:AddResponse" />
    </wsdl:message>
    <wsdl:message name="ICalculator_Subtract_InputMessage">
        <wsdl:part name="parameters" element="sns:Subtract" />
    </wsdl:message>
    <wsdl:message name="ICalculator_Subtract_OutputMessage">
        <wsdl:part name="parameters" element="sns:SubtractResponse" />
    </wsdl:message>
    <wsdl:portType name="ICalculator">
        <wsdl:operation name="Add">
            <wsdl:input wsaw:Action="http://Example.org/ICalculator/Add" message="tns:ICalculator_Add_InputMessage" />
            <wsdl:output wsaw:Action="http://Example.org/ICalculator/AddResponse" message="tns:ICalculator_Add_OutputMessage" />
        </wsdl:operation>
        <wsdl:operation name="Subtract">
            <wsdl:input wsaw:Action="http://Example.org/ICalculator/Subtract" message="tns:ICalculator_Subtract_InputMessage" />
            <wsdl:output wsaw:Action="http://Example.org/ICalculator/SubtractResponse" message="tns:ICalculator_Subtract_OutputMessage" />
        </wsdl:operation>
    </wsdl:portType>
    <wsdl:binding name="DefaultBinding_ICalculator" type="tns:ICalculator">
        <soap:binding transport="http://schemas.xmlsoap.org/soap/http" />
        <wsdl:operation name="Add">
            <soap:operation soapAction="http://Example.org/ICalculator/Add" style="document" />
            <wsdl:input>
                <soap:body use="literal" />
            </wsdl:input>
            <wsdl:output>
                <soap:body use="literal" />
            </wsdl:output>
        </wsdl:operation>
        <wsdl:operation name="Subtract">
            <soap:operation soapAction="http://Example.org/ICalculator/Subtract" style="document" />
            <wsdl:input>
                <soap:body use="literal" />
            </wsdl:input>
            <wsdl:output>
                <soap:body use="literal" />
            </wsdl:output>
        </wsdl:operation>
    </wsdl:binding>
    <wsdl:service name="CalculatorService">
        <wsdl:port name="ICalculator" binding="tns:DefaultBinding_ICalculator">
            <soap:address location="http://localhost/ICalculator" />
        </wsdl:port>
    </wsdl:service>
</wsdl:definitions>

We could install it via command:

karaf@root()> install -s wsdl:file:PUT_PATH_TO_WSDL_HERE/exampleService-2.0.0.wsdl\$package=org.github.alien11689.example&s1=http://Example.org/schema&t1=org.github.alien11689.example.schema
Bundle ID: 54

File must have format ${bundleSymbolicName}-${version}.wsdl.

Provided options are:

  • package – allows to change package of generated interface
  • pair s1 and t1 – maps schema in WSDL to package (WSDL deployer is in draft verion nowadays provides options to map only one schema).

Karaf has installed this file:

karaf@root()> headers 54

Bundle 54
---------
Manifest-Version = 2

Bundle-ManifestVersion = 2
Bundle-SymbolicName = exampleService-2.0.0.wsdl
Bundle-Version = 2.0.0

Export-Package =
    org.github.alien11689.example.schema;version=2.0.0,
    org.github.alien11689.example;version=2.0.0
Import-Package =
    javax.jws,
    javax.jws.soap,
    javax.xml.bind.annotation,
    javax.xml.namespace,
    javax.xml.ws

Install WSDL by putting it into Karaf drop folder

You can also install WSDL file by copying it to deploy directory:

cp PUT_PATH_TO_WSDL_HERE/exampleService-2.0.0.wsdl PUT_PATH_TO_KARAF_DIR_HERE/deploy/deployedExampleService-2.0.0.wsdl

It is much more simple to do, but do not allow for customization (e. g. namespace to package mapping). It creates bundle:

karaf@root()> list | grep deployedExampleService
55 | Active |  80 | 2.0.0          | deployedExampleService-2.0.0.wsdl
karaf@root()> headers 55

Bundle 55
---------
Manifest-Version = 2

Bundle-ManifestVersion = 2
Bundle-SymbolicName = deployedExampleService-2.0.0.wsdl
Bundle-Version = 2.0.0

Export-Package =
    org.example;version=2.0.0,
    org.example.schema;version=2.0.0
Import-Package =
    javax.jws,
    javax.jws.soap,
    javax.xml.bind.annotation,
    javax.xml.namespace,
    javax.xml.ws

How does it work?

Deployer uses wsimport command to create in temporary directory and compile generated java classes. Compiled class are packed with MANIFEST.MF into service.jar and such jar is really installed in OSGi container. For example, my temporary directory is /tmp/4ff81631-3c08-487a-b731-1f95c568026f:

$ tree /tmp/4ff81631-3c08-487a-b731-1f95c568026f
/tmp/4ff81631-3c08-487a-b731-1f95c568026f
├── Jaxb-binding.xml
├── Jaxws-binding.xml
├── service.wsdl
├── src
│   └── org
│       └── github
│           └── alien11689
│               └── example
│                   ├── CalculatorService.java
│                   ├── ICalculator.java
│                   └── schema
│                       ├── Add.java
│                       ├── AddResponse.java
│                       ├── ObjectFactory.java
│                       ├── package-info.java
│                       ├── Subtract.java
│                       └── SubtractResponse.java
└── target
    ├── org
    │   └── github
    │       └── alien11689
    │           └── example
    │               ├── CalculatorService.class
    │               ├── ICalculator.class
    │               └── schema
    │                   ├── Add.class
    │                   ├── AddResponse.class
    │                   ├── ObjectFactory.class
    │                   ├── package-info.class
    │                   ├── Subtract.class
    │                   └── SubtractResponse.class
    └── service.jar

And my service.jar contains:

$ jar tf /tmp/4ff81631-3c08-487a-b731-1f95c568026f/target/service.jar
META-INF/
META-INF/MANIFEST.MF
org/
org/github/
org/github/alien11689/
org/github/alien11689/example/
org/github/alien11689/example/schema/
org/github/alien11689/example/schema/Add.class
org/github/alien11689/example/schema/ObjectFactory.class
org/github/alien11689/example/schema/Subtract.class
org/github/alien11689/example/schema/SubtractResponse.class
org/github/alien11689/example/schema/package-info.class
org/github/alien11689/example/schema/AddResponse.class
org/github/alien11689/example/ICalculator.class
org/github/alien11689/example/CalculatorService.class

Conclusion

WSDL generation and Karaf deployers could be easily joined and simplified creation of OSGi bundles without explicite creation of jar. Provided WSDL deployer is just draft, but could be very useful when we have many WSDLs and do not want to create separate artifacts for them.

Source code of WSDL deployer is provided here.

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DDevelopment & Design

Super Confitura Man

How Super Confitura Man came to be :)

Recently at TouK we had a one-day hackathon. There was no main theme for it, you just could post a project idea, gather people around it and hack on that idea for a whole day - drinks and pizza included.

My main idea was to create something that could be fun to build and be useful somehow to others. I’d figured out that since Confitura was just around a corner I could make a game, that would be playable at TouK’s booth at the conference venue. This idea seemed good enough to attract Rafał Nowak @RNowak3 and Marcin Jasion @marcinjasion - two TouK employees, that with me formed a team for the hackathon.

Confitura 01

The initial plan was to develop a simple mario-style game, with preceduraly generated levels, random collectible items and enemies. One of the ideas was to introduce Confitura Man as the main character, but due to time constraints, this fall through. We’ve decided to just choose a random available sprite for a character - hence the onion man :)

Confitura 02

How the game is played?

Since we wanted to have a scoreboard and have unique users, we’ve printed out QR codes. A person that would like to play the game could pick up a QR code, show it against a camera attached to the play booth. The start page scanned the QR code and launched the game with username read from paper code.

The rest of the game was playable with gamepad or keyboard.

Confitura game screen

Technicalities

Writing a game takes a lot of time and effort. We wanted to deliver, so we’ve decided to spend some time in the days before the hackathon just to bootstrap the technology stack of our enterprise.

We’ve decided that the game would be written in some Javascript based engine, with Google Chrome as a web platform. There are a lot of HTML5 game engines - list of html5 game engines and you could easily create a game with each and every of them. We’ve decided to use Phaser IO which handles a lot of difficult, game-related stuff on its own. So, we didn’t have to worry about physics, loading and storing assets, animations, object collisions, controls input/output. Go see for yourself, it is really nice and easy to use.

Scoreboard would be a rip-off from JIRA Survivor with stats being served from some web server app. To make things harder, the backend server was written in Clojure. With no experience in that language in the team, it was a bit risky, but the tasks of the server were trivial, so if all that clojure effort failed, it could be rewritten in something we know.

Statistics

During the whole Confitura day there were 69 unique players (69 QR codes were used), and 1237 games were played. The final score looked like this:

  1. Barister Lingerie 158 - 1450 points
  2. Boilerdang Custardbath 386 - 1060 points
  3. Benadryl Clarytin 306 - 870 points

And the obligatory scoreboard screenshot:

Confitura 03

Obstacles

The game, being created in just one day, had to have problems :) It wasn’t play tested enough, there were some rough edges. During the day we had to make a few fixes:

  • the server did not respect the highest score by specific user, it was just overwritting a user’s score with it’s latest one,
  • there was one feature not supported on keyboard, that was available on gamepad - turbo button
  • server was opening a database connection each time it got a request, so after around 5 minutes it would exhaust open file limit for MongoDB (backend database), this was easily fixed - thou the fix is a bit hackish :)

These were easily identified and fixed. Unfortunately there were issues that we were unable to fix while the event was on:

  • google chrome kept asking for the permission to use webcam - this was very annoying, and all the info found on the web did not work - StackOverflow thread
  • it was hard to start the game with QR code - either the codes were too small, or the lighting around that area was inappropriate - I think this issue could be fixed by printing larger codes,

Technology evaluation

All in all we were pretty happy with the chosen stack. Phaser was easy to use and left us with just the fun parts of the game creation process. Finding the right graphics with appropriate licensing was rather hard. We didn’t have enough time to polish all the visual aspects of the game before Confitura.

Writing a server in clojure was the most challenging part, with all the new syntax and new libraries. There were tasks, trivial in java/scala, but hard in Clojure - at least for a whimpy beginners :) Nevertheless Clojure seems like a really handy tool and I’d like to dive deeper into its ecosystem.

Source code

All of the sources for the game can be found here TouK/confitura-man.

The repository is split into two parts:

  • game - HTML5 game
  • server - clojure based backend server

To run the server you need to have a local MongoDB installation. Than in server’s directory run: $ lein ring server-headless This will start a server on http://localhost:3000

To run the game you need to install dependencies with bower and than run $ grunt from game’s directory.

To launch the QR reading part of the game, you enter http://localhost:9000/start.html. After scanning the code you’ll be redirected to http://localhost:9000/index.html - and the game starts.

Conclusion

Summing up, it was a great experience creating the game. It was fun to watch people playing the game. And even with all those glitches and stupid graphics, there were people vigorously playing it, which was awesome.

Thanks to Rafał and Michał for great coding experience, and thanks to all the players of our stupid little game. If you’d like to ask me about anything - feel free to contact me by mail or twitter @zygm0nt

Recently at TouK we had a one-day hackathon. There was no main theme for it, you just could post a project idea, gather people around it and hack on that idea for a whole day - drinks and pizza included.

My main idea was to create something that could be fun to build and be useful somehow to others. I’d figured out that since Confitura was just around a corner I could make a game, that would be playable at TouK’s booth at the conference venue. This idea seemed good enough to attract >Conclusion