This is a problem in Java. I think you cannot dynamically modify the initial system class loader.
What most apps do is check for the thread context class loader when dynamically loading classes. We can check and make sure that one is set, but if Closure does not respect that, we have a problem. Then Closure is not built for dynamic class loading. On Thu, Dec 10, 2015 at 5:15 PM, Matthias J. Sax <mj...@apache.org> wrote: > Would it make sense (if possible?) for Flink to add the user jar > dynamically to it's own classpath so Clojure can find it? Or somehow > modify Clojure's class loader? > > The jars in lib are added to the classpath at startup. This makes it > practically impossible to execute a Flink program that is written in > Clojure right now... > > > On 12/10/2015 05:09 PM, Aljoscha Krettek wrote: > > Clojure is not considering the user-jar when trying to load the class. > > > >> On 10 Dec 2015, at 17:05, Matthias J. Sax <mj...@apache.org> wrote: > >> > >> Hi Squirrels, > >> > >> I was playing with a Flink Clojure WordCount example today. > >> https://github.com/mjsax/flink-external/tree/master/flink-clojure > >> > >> After building the project with "mvn package" I tried to submit it to a > >> local cluster. Before I started the cluster, I manually copied > >> "clojure-1.5.1.jar" into Flink's lib folder. > >> > >>> cp ~/.m2/repository/org/clojure/clojure/1.5.1/clojure-1.5.1.jar lib/ > >>> bin/start-local.sh > >> > >> However, when submitting the jar, I get an exception: > >> > >>> bin/flink run -c org.apache.flink.clojure.WordCount > >> > ~/workspace_flink/flink-external/flink-clojure/target/flink-clojure-0.10.0.jar > >> > >> > >>> ------------------------------------------------------------ > >>> The program finished with the following exception: > >>> > >>> org.apache.flink.client.program.ProgramInvocationException: The > program's entry point class 'org.apache.flink.clojure.WordCount' threw an > error during initialization. > >>> at > org.apache.flink.client.program.PackagedProgram.loadMainClass(PackagedProgram.java:585) > >>> at > org.apache.flink.client.program.PackagedProgram.<init>(PackagedProgram.java:195) > >>> at > org.apache.flink.client.CliFrontend.buildProgram(CliFrontend.java:784) > >>> at org.apache.flink.client.CliFrontend.run(CliFrontend.java:288) > >>> at > org.apache.flink.client.CliFrontend.parseParameters(CliFrontend.java:1050) > >>> at org.apache.flink.client.CliFrontend.main(CliFrontend.java:1103) > >>> Caused by: java.lang.ExceptionInInitializerError > >>> at java.lang.Class.forName0(Native Method) > >>> at java.lang.Class.forName(Class.java:278) > >>> at > org.apache.flink.client.program.PackagedProgram.loadMainClass(PackagedProgram.java:578) > >>> ... 5 more > >>> Caused by: java.io.FileNotFoundException: Could not locate > org/apache/flink/clojure/WordCount__init.class or > org/apache/flink/clojure/WordCount.clj on classpath: > >>> at clojure.lang.RT.load(RT.java:443) > >>> at clojure.lang.RT.load(RT.java:411) > >>> at clojure.core$load$fn__5018.invoke(core.clj:5530) > >>> at clojure.core$load.doInvoke(core.clj:5529) > >>> at clojure.lang.RestFn.invoke(RestFn.java:408) > >>> at clojure.lang.Var.invoke(Var.java:415) > >>> at org.apache.flink.clojure.WordCount.<clinit>(Unknown Source) > >>> ... 8 more > >> > >> I am not sure why the class is not found. It is contained in the jar > >> file. I can fix this error by copying the user jar > >> (flink-clojure-0.10.0.jar) into Flink's lib-folder. > >> > >> It seems, that Flink is not looking into the user-jar when loading this > >> class. Can anybody explain why? > >> > >> Thx. > >> > >> -Matthias > >> > > > >
