REST client inside of OSGi application - java

I need to integrate a REST client into an existing OSGi application implemented using Apache Felix. The REST service is based on RESTeasy implementation (version 2.3.2.Final) of JAX-RS. I created a separate bundle with clients' dependencies, exporting required RESTeasy packages and importing them in the bundle where the client is used, but unfortunately I cannot get it working inside of the OSGi context.
I tried two different approaches. First one using the generic ClientRequest:
ClientRequest request = new ClientRequest(MyService.URL_TEST+"/stats");
request.body(javax.ws.rs.core.MediaType.APPLICATION_XML, stats);
ClientResponse<String> response = request.post(String.class);
The error that I get in this case is pretty weird:
[java] java.lang.RuntimeException: java.lang.ClassCastException:
org.jboss.resteasy.client.core.executors.ApacheHttpClient4Executor cannot be cast to
org.jboss.resteasy.client.ClientExecutor
where I it is known for sure that ApacheHttpClient4Executor implements the ClientExecutor interface.
When I try to use my own REST client wrapper around RESTeasy like this:
MyService myService = MyServiceClient.getInstance();
myService.saveStatistics(stats);
I get a different exception:
[java] java.lang.LinkageError: ClassCastException: attempting to
castjar:file:/D:/Development/Eclipses/eclipse_4.2_j2ee_x64/lib/jaxrs-api-2.3.2.Final.jar
!/javax/ws/rs/ext/RuntimeDelegate.classtobundle:
//78.0:1/javax/ws/rs/ext/RuntimeDelegate.class
As far as I understand, the LinkageError most probably has to do with the way RESTeasy initializes the RuntimeDelegate using some classloader tricks, which probably fall under the restrictions of OSGi framework. I get the suspicion that the java.lang.ClassCastException mentioned first has the same source.
Is there any way to get RESTeasy working inside of OSGi?
PS: discussion about a similar issue with RESTeasy, but outside of OSGi: java.lang.LinkageError: ClassCastException
Update:
these are the libraries included into restclient bundle:
activation-1.1.jar commons-codec-1.2.jar commons-httpclient-3.1.jar commons-io-2.1.jar commons-logging-1.0.4.jar flexjson-2.1.jar httpclient-4.1.2.jar httpcore-4.1.2.jar javassist-3.12.1.GA.jar jaxb-api-2.2.3.jar jaxb-impl-2.2.4.jar jaxrs-api-2.3.2.Final.jar jcip-annotations-1.0.jar jettison-1.3.1.jar jsr250-api-1.0.jar junit-4.10.jar log4j-1.2.14.jar resteasy-jaxb-provider-2.3.2.Final.jar resteasy-jaxrs-2.3.2.Final.jar resteasy-jettison-provider-2.3.2.Final.jar scannotation-1.0.3.jar slf4j-api-1.6.4.jar slf4j-log4j12-1.6.4.jar myservice-common-0.1.0.3.jar my-service-client-0.1.0.3-SNAPSHOT.jar stax-api-1.0-2.jar xmlpull-1.1.3.1.jar xpp3_min-1.1.4c.jar xstream-1.4.2.jar
These are the exports from the restclient bundle: javax.ws.rs, javax.ws.rs.ext, javax.ws.rs.core, org.jboss.resteasy.client, org.jboss.resteasy.client.cache, org.jboss.resteasy.client.extractors, org.jboss.resteasy.client.marshallers, org.jboss.resteasy.client.core.executors, javax.xml.bind.annotation, org.jboss.resteasy.plugins.providers, org.jboss.resteasy.plugins.providers.jaxb, org.jboss.resteasy.spi

Have a look at the SpringSource Bundle Repo, it's got some very useful pre-built bundles of common libraries including the Apache HTTP Client which we are using (in conjunction with gson) to do our RESTful comms.

(unfortunately a legacy module of my project still uses OSGi, but using RESTeasy 3.0.16 now)
When I need to OSGify a dependency my preferred solution now is to wrap it using the excellent Apache Ops4j Pax Tipi project.
The project provides a preconfigured Maven setup (parent POM handles the bundling) and you just have to adapt the GAV coordinates of the original project in a Tipi sub module with a org.apache.ops4j.pax.tipi prefix and build the new bundle project which draws in the original dependency, unpacks and wraps it as OSGi bundle.
You can start from an existing Tipi sub project that best matches your project setup (dependencies, etc.) and adapt any OSGi imports/exports missing (most often, these are created automatically by the maven-bundle-plugin anyway).
This worked quite well for me as long as the original project did not contain too many exotic or malformed dependencies.
However you may run into snags like transitive dependencies using the root package, as I currently experience, which can be a real show stopper (finding out which library is a real nightmare).
Unfortunately, RESTeasy seems to be affected by this, as I get exactly the same error (default package , even after declaring non-test and non-provided dependencies as optional:
The default package '.' is not permitted by the Import-Package syntax.
Upgrading the maven-bundle-plugin to the latest release 3.0.1 yields a different error (even less helpful):
[ERROR] Bundle org.ops4j.pax.tipi:org.ops4j.pax.tipi.resteasy-jaxrs:bundle:3.0.16.Final.1 : Can not parse name from bundle native code header:
[ERROR] Error(s) found in bundle configuration
Update seems to be solved by upping Tipi version in POM to 1.4.0, testing...

Is RESTEasy mandatory ?
I personally use jersey in OSGi and it is working perfectly, both as client and server.

This problem isn't limited to RESTeasy. It also occurs with Jersey.
It is occurring because you have two copies of the JAX-RS classes on the classpath.
You can see this in the LinkageError:
[java] java.lang.LinkageError: ClassCastException: attempting to cast jar:file:/D:/Development/Eclipses/eclipse_4.2_j2ee_x64/lib/jaxrs-api-2.3.2.Final.jar!/javax/ws/rs/ext/RuntimeDelegate.class to bundle://78.0:1/javax/ws/rs/ext/RuntimeDelegate.class
i.e. one copy is coming from:
D:/Development/Eclipses/eclipse_4.2_j2ee_x64/lib/jaxrs-api-2.3.2.Final.jar
and the other from the OSGI bundle.
This causes problems for the RuntimeDelegate class, which by default uses the system class loader to create the RuntimeDelegate implementation (see javax.ws.rs.ext.FactoryFinder).
The problem can also occur if the same jar is loaded via two different class loaders.
There are a couple of workarounds:
remove the jaxrs-api-2.3.2.Final.jar from the system class path
set the thread context class loader to that of your bundle, prior to making any JAX-RS calls.
The FactoryFinder will use this to load the RuntimeDelegate.
To avoid polluting your code with calls to Thread.currentThread().setContextClassLoader(myBundleClassLoader), you can wrap your JAX-RS client using a Proxy. e.g. see the Thread context classloader section of https://puredanger.github.io/tech.puredanger.com/2007/06/15/classloaders/

Related

LogConfigurationException when using HttpClient

When my code executes this line:
DefaultHttpClient httpclient = new DefaultHttpClient();
I'm getting this Exception:
org.apache.commons.logging.LogConfigurationException: Class org.apache.commons.logging.impl.Log4JLogger does not implement Log
does somebody know how can I solve that?
Maybe is not important (or maybe it is), but the app is a plugin for Jira, and is using Maven for the dependencies.
Thanks !
EDIT:
EDIT 2:
Could this be related with OSGi from Jira?
How can I use commons-logging in an OSGi environment?
From here:
http://wiki.apache.org/commons/Logging/FrequentlyAskedQuestions
Commons-logging was not designed with OSGi in mind. This is why it is
difficult to get commons-logging working in OSGi environments:
LogFactory loads Log implementations by name (see
Class.forName(String)). This is usually not possible in OSGi since
every bundle classloader can only see the classes a bundle defines
imports for. The bundle class loader that loads the commons-logging
bundle will not have access to user provided
commons-logging.properties files. commons-logging-api.jar contains
classes that are also included in commons-logging.jar. This is
contrary to traditional OSGi application architectures where one
bundle defines an API and other bundles provide implementations for
that API. There alternatives to using commons-logging directly in OSGi
are:
Rebundled versions that contain proper OSGi meta data are available
from Apache Felix, SpringSource and Eclipse Orbit. Using Pax logging.
Further information about this topic is available in the archives of
the commons dev ML and the felix dev ML and in Jira.
and when I try to access to the OSGi tab from Jira (going to JIRASERVER/plugins/servlet/upm/osgi#osgi) I can see an exception:
classNotFoundException: org.apache.commons.logging.impl.SLF4JLogFactory
And also I can see from the IDE (when searching for Log4JLogger class) that I have two definitions:
package org.apache.commons.logging.impl.Log4JLogger
public class Log4JLogger implements Log, Serializable {
and
package com.atlassian.extras.common.log;
class Log4jLogger implements com.atlassian.extras.common.log.Logger.Log {
this is really confusing....
I'm not sure, but could it be that the logger you configured does not correspond to the logger in your pom dependencies? Perhaps a different version?

Using Coda Hale Yammer Metrics library in Websphere Application Server 7

I am trying to add metrics library to existing webservice on WAS 7. I am getting below error
Error 404: javax.servlet.UnavailableException: SRVE0203E: Servlet [AdminServlet]: com.yammer.metrics.reporting.AdminServlet was found, but is missing another required class. SRVE0206E: This error typically implies that the servlet was originally compiled with classes which cannot be located by the server. SRVE0187E: Check your class path to ensure that all classes required by the servlet are present.SRVE0210I: This problem can be debugged by recompiling the servlet using only the classes in the application's runtime class path SRVE0234I
What are the other run-time dependencies required for metrics-servlet-2.2.0?
I have metrics-core-2.2.0.jar and metrics-servlet-2.2.0.jar in my WEB-INF\lib folder.
Threads, ping and healthcheck servlets work fine.
I think your missing some more required jars, are you not using maven or gradle for dependency management
Please refer here to know all required jars that metrics-servlet-2.2.0.jar depends on. http://mvnrepository.com/artifact/com.yammer.metrics/metrics-servlets/3.0.0-BETA1
My suggestion is, it is always difficult to maintain dependencies without Maven/Gradle or any other build tools :).

Unable to add jar to OSGi bundle

Yet another silly question. I am sure it is something easy, but that already took me a lot of time and I don't get it working ;(
I have a written a working prototype to make a rest call to a server. To do this I utilize "jersey-client-1.14.jar". That works quite well by adding it to the eclipse projects class path.
Now I am trying to do the same in an OSGi bundle. These were the steps I did:
I created a /lib folder in my OSGi bundle project.
Added the jersey-client-1.14.jar in that folder.
Added the jar in the MANIFEST.MF in the classpath: Bundle-ClassPath: ., lib/jersey-client-1.14.jar
Checked that it was also correctly added to the projects classpath.
In the Eclipse workspace I have no compiling errors.
At runtime I have the phenomenon that I get a classdef not found exception when creating the jersey client with Client.create();
!ENTRY org.eclipse.equinox.event 4 0 2012-11-08 23:14:43.975
!MESSAGE Exception while dispatching event org.osgi.service.event.Event [topic=openhab/command/Hue_Bulb_2] to handler org.openhab.binding.hue.internal.HueBinding#70f5f42b
!STACK 0
java.lang.NoClassDefFoundError: Could not initialize class com.sun.jersey.spi.service.ServiceFinder
at com.sun.jersey.api.client.Client.init(Client.java:213)
at com.sun.jersey.api.client.Client.access$000(Client.java:118)
at com.sun.jersey.api.client.Client$1.f(Client.java:191)
at com.sun.jersey.api.client.Client$1.f(Client.java:187)
at com.sun.jersey.spi.inject.Errors.processWithErrors(Errors.java:193)
at com.sun.jersey.api.client.Client.(Client.java:187)
at com.sun.jersey.api.client.Client.(Client.java:159)
at com.sun.jersey.api.client.Client.create(Client.java:669)
at org.openhab.binding.hue.internal.bridge.HueBridge.getSettingsJson(HueBridge.java:64)
at org.openhab.binding.hue.internal.bridge.HueBridge.pairBridgeIfNecessary(HueBridge.java:19)
at org.openhab.binding.hue.internal.HueBinding.receiveCommand(HueBinding.java:37)
at org.openhab.core.events.AbstractEventSubscriber.handleEvent(AbstractEventSubscriber.java:62)
at org.eclipse.equinox.internal.event.EventHandlerWrapper.handleEvent(EventHandlerWrapper.java:197)
at org.eclipse.equinox.internal.event.EventHandlerTracker.dispatchEvent(EventHandlerTracker.java:197)
at org.eclipse.equinox.internal.event.EventHandlerTracker.dispatchEvent(EventHandlerTracker.java:1)
at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230)
at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:148)
at org.eclipse.equinox.internal.event.EventAdminImpl.dispatchEvent(EventAdminImpl.java:135)
at org.eclipse.equinox.internal.event.EventAdminImpl.sendEvent(EventAdminImpl.java:78)
at org.eclipse.equinox.internal.event.EventComponent.sendEvent(EventComponent.java:39)
at org.openhab.core.internal.events.EventPublisherImpl.sendCommand(EventPublisherImpl.java:76)
at org.openhab.ui.webapp.internal.servlet.CmdServlet.service(CmdServlet.java:115)
at org.eclipse.equinox.http.servlet.internal.ServletRegistration.service(ServletRegistration.java:61)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:128)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:60)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:598)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:486)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:231)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1065)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:413)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:192)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:999)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:250)
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:149)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:111)
at org.eclipse.jetty.server.Server.handle(Server.java:350)
at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:454)
at org.eclipse.jetty.server.AbstractHttpConnection.headerComplete(AbstractHttpConnection.java:890)
at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:944)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:630)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:230)
at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:77)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:606)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:46)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:603)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:538)
at java.lang.Thread.run(Thread.java:680)
23:14:43.992 ERROR OSGi[:98] - Exception while dispatching event org.osgi.service.event.Event [topic=openhab/command/Hue_Bulb_2] to handler org.openhab.binding.hue.internal.HueBinding#70f5f42b
java.lang.NoClassDefFoundError: Could not initialize class com.sun.jersey.spi.service.ServiceFinder
at com.sun.jersey.api.client.Client.init(Client.java:213)
at com.sun.jersey.api.client.Client.access$000(Client.java:118)
at com.sun.jersey.api.client.Client$1.f(Client.java:191)
at com.sun.jersey.api.client.Client$1.f(Client.java:187)
at com.sun.jersey.spi.inject.Errors.processWithErrors(Errors.java:193)
at com.sun.jersey.api.client.Client.(Client.java:187)
at com.sun.jersey.api.client.Client.(Client.java:159)
at com.sun.jersey.api.client.Client.create(Client.java:669)
at org.openhab.binding.hue.internal.bridge.HueBridge.getSettingsJson(HueBridge.java:64)
at org.openhab.binding.hue.internal.bridge.HueBridge.pairBridgeIfNecessary(HueBridge.java:19)
at org.openhab.binding.hue.internal.HueBinding.receiveCommand(HueBinding.java:37)
You'll also need to add jersey-core to you bundle's classpath, as jersey-client has it as a dependency.
You might alos have to add other dependencies if needed. The process is rather easy if not pleasant:
Add a jar
Run the app
See what class is not found, find the jar where that class lives, add it to the bundle classpath, go back to 2
One thing though: Jersey jars are OSGi-ready, so you might as well just add jersey-client.jar and jersey-core.jar to your taget platform and import the required packages.
Looking at your secondary queries I think you just want to know what is going on :-)
OSGi fences JARs to create modules. By default, the fence is impenetrable, no classes outside the bundle (the jar) are visible (being able to load a class from) to classes on the inside, and outsiders cannot see anything inside the bundle. The advantage should be obvious: you can change the inside to your hearts delight since nothing is known outside.
However, in real life you need some holes in the fence to be able to collaborate with others. In your case a bundle tries to load com.sun.jersey.spi.service.ServiceFinder but it runs into the fence because there is no appropriate hole.
The "holes" in OSGi are packages, these are the shared atoms. You list these packages in the manifest. The Import-Package header indicates the packages that you need to see from the outside world and the Export-Package header defines what packages (and under what version) the packages are visible to other bundles.
Obviously you do not want to manually calculate the imports since these are already in your class files, for this reason there is a tool bnd (I am the author) that can be used from maven, ant, gradle, etc. It takes a recipe and calculates the resulting bundle with proper metadata. This tool is extensively supported with the bndtools Eclipse plugin, which is a very nice environment to learn more about OSGi and these issues.
Sir, in eclipse you have been added different package like.
com.sun.jersey.spi.service.ServiceFinder . to start ur service you have to start other service. on which you bundle is dependent.
like i have an jar, which is depependent on rxtxcomm_api-2.1.7.jar.
i had to initialize it or you can say intiat it. before my service. please check it.
Embedding jars is a bad style in OSGi. Generally you should only do this if there is no other way. Embedding jars will easily lead to classpath problems as packages then may come from different bundles. Is there a special reason why you want to embed the jar?
Jersey is fully OSGi ready since version 1.2. See the documentation for examples how to use it.
Most OSGi containers come with a JAX-RS implementation out-of-the-box - being Jersey or what-not. For instance, we're using Apache ServiceMix, which conveniently provides Apache CXF.
What container are you using?
Do you really have to bundle Jersey with your application?
If you need to bundle Jersey for whatever reason, can you please provide an example of your manifest file.
Have you considered using the Maven-Bundle-Plugin?

java.util.logging, ResourceBundles, SAAJ: exception on loading Glassfish OSGi webapp bundle

I'm being driven out of my mind by the following exception:
java.lang.IllegalArgumentException:
com.sun.xml.messaging.saaj.soap.LocalStrings != com.sun.xml.internal.messaging.saaj.soap.LocalStrings
at java.util.logging.Logger.getLogger(Logger.java:357)
at com.sun.xml.internal.messaging.saaj.soap.SAAJMetaFactoryImpl.<clinit>(SAAJMetaFactoryImpl.java:41)
It's occurring when I try to deploy a WAB (web application OSGi bundle) to Glassfish (3.1.1).
I'm trying to use an up-to-date version of SAAJ (com.sun.xml.messaging.saaj...) rather than the old JDK one (which is the com.sun.xml.internal.saaj... one), by putting the string com.sun.xml.messaging.saaj.soap.ver1_1.SOAPMessageFactory1_1Impl in the file META-INF/services/javax.xml.soap.MessageFactory.
It appears there is some logging going on before the OSGi classloading kicks in, and therefore the 'wrong' ResourceBundle is being returned during initialization of the static log field of com.sun.xml.messaging.saaj.soap.MessageFactoryImpl (SAAJ's implementation of javax.xml.soap.MessageFactory).
Anyone seen this / any workarounds on offer?
Never got to the bottom of this, but manifest voodoo eventually made it go away (with all of the javax.xml.ws / javax.ws.rs packages in Import-Package rather than on the bundle classpath WEB-INF/lib).
It was also possible to work around it by using
-Djavax.xml.soap.MessageFactory=com.sun.xml.messaging.saaj.soap.ver1_1.SOAPMessageFactory1_1Impl
on Glassfish startup, though obviously this forces that implementation on all users of MessageFactory.
See: JDK-6741342 : Logger.getLogger() throws java.lang.IllegalArgumentException on saaj classes.
Instead, it's related to the introduction of saaj into JDK 6.....and the workaround involved re-ordering jars.

web client for web service

I've a web-service that works fine when I access them from a J2SE (desktop) application. To access this service I do follow:
generate stub classes by wsdl link using java wsimport tool
then I create service using generated classes and run one of wsdl operations.It looks like this:
MyWebServiceService webService = new MyWebServiceService();
MyWebService port = webService.getMyWebServicePort();
webService.run("XYZ");
As I sad it work fine when I use it in a standalone application.
But...when I try to access web-service in the same way but from servlet-client, using generated stubs I get following error:
java.lang.ClassCastException: com.sun.xml.bind.v2.runtime.JAXBContextImpl cannot be cast to com.sun.xml.bind.api.JAXBRIContext
org.jboss.ws.metadata.umdm.EndpointMetaData.eagerInitializeAccessors(EndpointMetaData.java:686)
org.jboss.ws.metadata.umdm.EndpointMetaData.initializeInternal(EndpointMetaData.java:567)
org.jboss.ws.metadata.umdm.EndpointMetaData.eagerInitialize(EndpointMetaData.java:553)
org.jboss.ws.metadata.builder.jaxws.JAXWSClientMetaDataBuilder.rebuildEndpointMetaData(JAXWSClientMetaDataBuilder.java:314)
org.jboss.ws.core.jaxws.spi.ServiceDelegateImpl.getPortInternal(ServiceDelegateImpl.java:271)
org.jboss.ws.core.jaxws.spi.ServiceDelegateImpl.getPort(ServiceDelegateImpl.java:202)
javax.xml.ws.Service.getPort(Service.java:143...
I've searched google long time but found nothing helpful topics. Some topics show examples accessing web-services from servlet, but unfortunately I can't do this...( And don't know what is cause of trouble.
Application server: jboss 4.2.3GA
Is it possible to connect web-service from servlet? How?
I've tried use #WebServiceRef annotation, but it seem web-container can't inject web-service stub. And I think that container must not do this itself, because stub classes have already been generated by wsimport tool, and its enouph to use this classes for accessing of web-service.
Stub classes were generated using the following command:
wsimport -keep -p com.myhost.ws http://www.myhost.com/services/MyWebService?wsdl
Did you make sure your classpath does not contain multiple JAX-B Jars with differing versions ? The exception looks like a version conflict to me. Application servers usually have some kind of "endorsed" lib directory that holds JARS that are always added in front of web application classpaths. Maybe your app server has a conflicting JAX-B implementation there ?
If you use Maven to package your application, make sure transitive dependencies don't pull in unwanted JAX-B Jars (use 'mvn dependency:tree' to check this).
This definitely sounds like a JAXB conflict to me. Check out the jaxb versions that you have in your war and make sure that they are not conflicting with a jaxb jar that Jboss may have in its lib directory.
Addytionally if jbossws-native library was installed correctly the following packages should be deleted from jboss_home/lib/endorsed directory:
jboss-jaxrpc.jar
jboss-jaxws-ext.jar
jboss-jaxws.jar
jboss-saaj.jar
Otherwise you don't have ability to connect to web service through EJB or servlet.

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