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.

You May Also Like

Phonegap / Cordova and cross domain ssl request problem on android.

In one app I have participated, there was a use case:
  • User fill up a form.
  • User submit the form.
  • System send data via https to server and show a response.
During development there wasn’t any problem, but when we were going to release production version then some unsuspected situation occurred. I prepare the production version accordingly with standard flow for Android environment:
  • ant release
  • align
  • signing
During conduct tests on that version, every time I try to submit the form, a connection error appear. In that situation, at the first you should check whitelist in cordova settings. Every URL you want to connect to, must be explicit type in:
res/xml/cordova.xml
If whitelist looks fine, the error is most likely caused by inner implementation of Android System. The Android WebView does not allow by default self-signed SSL certs. When app is debug-signed the SSL error is ignored, but if app is release-signed connection to untrusted services is blocked.



Workaround


You have to remember that secure connection to service with self-signed certificate is risky and unrecommended. But if you know what you are doing there is some workaround of the security problem. Behavior of method
CordovaWebViewClient.onReceivedSslError
must be changed.


Thus add new class extended CordovaWebViewClient and override ‘onReceivedSslError’. I strongly suggest to implement custom onReceiveSslError as secure as possible. I know that the problem occours when app try connect to example.domain.com and in spite of self signed certificate the domain is trusted, so only for that case the SslError is ignored.

public class MyWebViewClient extends CordovaWebViewClient {

   private static final String TAG = MyWebViewClient.class.getName();
   private static final String AVAILABLE_SLL_CN
= "example.domain.com";

   public MyWebViewClient(DroidGap ctx) {
       super(ctx);
   }

   @Override
   public void onReceivedSslError(WebView view,
SslErrorHandler handler,
android.net.http.SslError error) {

String errorSourceCName = error.getCertificate().
getIssuedTo().getCName();

       if( AVAILABLE_SLL_CN.equals(errorSourceCName) ) {
           Log.i(TAG, "Detect ssl connection error: " +
error.toString() +
„ so the error is ignored”);

           handler.proceed();
           return;
       }

       super.onReceivedSslError(view, handler, error);
   }
}
Next step is forcing yours app to  use custom implementation of WebViewClient.

public class Start extends DroidGap
{
   private static final String TAG = Start.class.getName();

   @Override
   public void onCreate(Bundle savedInstanceState)
   {
       super.onCreate(savedInstanceState);
       super.setIntegerProperty("splashscreen", R.drawable.splash);
       super.init();

       MyWebViewClient myWebViewClient = new MyWebViewClient(this);
       myWebViewClient.setWebView(this.appView);

       this.appView.setWebViewClient(myWebViewClient);
       
// yours code

   }
}
That is all ypu have to do if minSdk of yours app is greater or equals 8. In older version of Android there is no class
android.net.http.SslError
So in class MyCordovaWebViewClient class there are errors because compliator doesn’t see SslError class. Fortunately Android is(was) open source, so it is easy to find source of the class. There is no inpediments to ‘upgrade’ app and just add the file to project. I suggest to keep original packages. Thus after all operations the source tree looks like:

Class SslError placed in source tree. 
 Now the app created in release mode can connect via https to services with self-signed SSl certificates.