Thank you very much for your answer. I will look further into R Service Bus.
In the meantime, I have posted an issue on GitHub https://github.com/s-u/rJava/issues/32 where I describe a way to reproduce the unexpected behaviour. Kind regards, Ben Le 30 sept. 2014 � 12:23, Mohan Radhakrishnan <radhakrishnan.mo...@gmail.com> a �crit : > Hi, > You could ask the author or post an issue here > .(https://github.com/s-u/rJava) > I had faced a problem and I got a response from him. > > In my case I am streaming JVM data and > this(http://www.openanalytics.eu/r-service-bus) may be a better idea. I > haven't still tried this. > > Thanks, > Mohan > > On Fri, Sep 26, 2014 at 5:25 PM, Beno�t Thi�bault <thieba...@artenum.com> > wrote: > Hi everyone, > > I want to call a Java application from R and have encountered some problems > with the way rJava deals with the system class loader. > > To run my application, I use the following R script: > > > library(rJava) > > .jinit() > > .jaddClassPath("myApp.jar") > > rWrapper <- .jnew("org/test/RWrapper") > > .jcall(rWrapper,"V","start") > > My Java application has a plugins loading mechanism that uses a specific > PluginClassLoader to load plugins stored in additional JAR files (e.g. > plugin.jar). This PluginClassLoader is programed so that it knows and loads > the plugins JARs. As any Java classloader, it is a child of the system class > loader. > > Finally, plugins not only use classes stored in their plugin.jar file, they > also depend on classes contained in the main myApp.jar file (the Plugin > interface is for example defined in the myApp.far) > > In a pure Java environment, myApp.jar is known from the system class loader > (it is in the classpath) and thus the PluginClassLoader can load classes from > the plugin (it knows both about the plugin.jar and the myApp.jar files) > > In the R context however, using the above script, its the RJavaClassLoader > that knows about the myApp.jar file. The org.test.RWrapper class is > instatiated by the RJavaClassLoader. The system class loader however does not > know about myApp.jar anymore. Neither does the PluginClassLoader. So when the > PluginClassLoader loads a plugin class, it can only load classes that are in > the plugin.jar file and as soon as a class from the myApp.jar file is > required by the plugin, it crashes with a java.lang.NoClassDefFoundError > message. > > My question is: how can I force rJava to load the classpath in the system > classloader and not only in the RJavaClassLoader? > > I cannot make the PluginClassLoader know the RJavaClassLoader as my > application also has to run in a non-R environment. > > Thanks for your time, > > Kind regards, > > Ben > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > -- Dr Beno�t Thi�bault Project Manager Artenum Toulouse - Science & Groupware http://www.artenum.com B�timent Calfocenter 10, rue Marguerite-Long 31320 Castanet-Tolosan France Phone: +33 (0)5 82 95 19 00 [[alternative HTML version deleted]]
______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
