Re: [Py4j-users] Help Requested: error when accessing jvm for basic sample
Status: Beta
Brought to you by:
barthe
Menu
▾
▴
Re: [Py4j-users] Help Requested: error when accessing jvm for basic sample
|
From: Barthelemy D. <ba...@cs...> - 2011-04-19 15:27:25
|
Ahhh... sorry, I'm not often working on Windows and I just found out that the doc is incorrect: The jar file should be in: Python27\Lib\site-packages\Py4J-0.6-py2.7.egg\share\py4j I'll have to check whether it is caused by Windows or easy_install (I usually use pip). Barthélémy On Tue, April 19, 2011 11:13 am, Sean Silvestri wrote: > Interesting I did the easy install option but cant seem to find the > py4j.jar file on my system. could it be in another location other than > python27\share as that directory doesnt exist. cheers, Sean > > > On Tue, Apr 19, 2011 at 2:55 AM, Barthelemy Dagenais <ba...@cs...> > wrote: > >> Hi Sean, >> >> >> The way Py4J works is that python code is executed in a Python >> interpreter and Java code is invoked by a Java Virtual Machine. Both the >> Python >> interpreter and the JVM must be started prior to using Py4J. In other >> words, Py4J won't start a JVM to execute code in a jar file. >> >> >> To run the example, first, locate the py4j.jar and your jar and execute >> this command (using the right path): >> >> java -cp path\to\py4j.jar;path\to\yourlib.jar \ >> py4j.examples.AdditionApplication >> >> Then, open a python interpreter and try the example code, it should >> work. >> >> You should also be able to access the code in your jar file. >> >> >> Hope this helps, >> Barthélémy >> >> >> On 04/18/2011 08:43 PM, Sean Silvestri wrote: >> >>> >>> Hi Barthelemy, >>> Interesting, I did not start any Java program. I must have >>> misunderstood the premise of the module. My main goal is to simply call >>> into a java jar file that I've registered e.g. the classpath. >>> >>> Since that was not working I just resorted to the basic sample on the >>> web site using the .java.util.Random class (see below) I'm simply >>> wanting to interface with a jar file in order to call the java >>> methods. gateway = JavaGateway() # connect to the >>> JVM >>> >>>>>> >>>>>> random = gateway.jvm.java.util.Random() # create a >>>>>> java.util.Random instance number1 = random.nextInt(10) >>>>>> # call the Random.nextInt >>>>>> method number2 = random.nextInt(10) print(number1,number2) >>> >>> (2, 7) >>> >>> >>> I had also turned off my firewall but still had gotten the error i >>> had mentiond ( [Errno 10061] No connection could be made because the >>> target machine actively refused it). >>> >>> What would be the steps to be able to call java code situated in a >>> .jar file from a python script using py4j? >>> many thanks, Sean >>> >>> >>> >>> >>> On Mon, Apr 18, 2011 at 5:21 PM, Barthelemy >>> Dagenais<ba...@cs...> >>> wrote: >>> >>>> >>>> Hi Sean, >>>> >>>> >>>> this error means that the python interpreter cannot connect to the >>>> jvm either because: >>>> >>>> 1- The jvm is not yet started so nothing is listening on the >>>> default py4j port. >>>> >>>> 2- You have a firewall blocking the port. >>>> >>>> >>>> You need to start the java program in the example and then, you can >>>> start your python interpreter (not the other way around). >>>> >>>> If you don't have a firewall and if you started the Java program >>>> before running the interpreter, we will need more information to >>>> help you (e.g., how did you start the Java program, what is the >>>> output of the "netstat" command in a command prompt after starting >>>> the Java program, etc.). >>>> >>>> Barthélémy >>>> >>>> >>>> On Mon, April 18, 2011 8:07 pm, Sean Silvestri wrote: >>>> >>>>> >>>>> HI All, >>>>> I'm just getting started with Py4J, basically just trying to call >>>>> a jar. I'm having trouble with the basic sample however: >>>>> >>>>> >>>>>>>> from py4j.java_gateway import JavaGateway gateway = >>>>>>>> JavaGateway() >>>>>>>> # connect to the JVM >>>>>>>> random = gateway.jvm.java.util.Random() # create a >>>>>>>> java.util.Random instance number1 = random.nextInt(10) # >>>>>>>> call the Random.nextInt method number2 = random.nextInt(10) >>>>>>>> print(number1,number2) >>>>> >>>>> (2, 7) >>>>> >>>>> >>>>>>>> addition_app = gateway.entry_point # get the >>>>>>>> AdditionApplication instance >>>>>>>> addition_app.addition(number1,number2) # call the >>>>>>>> addition method >>>>>>>> >>>>> 9 >>>>> >>>>> >>>>> >>>>> I keep getting the following error: [Errno 10061] No connection >>>>> could be made because the target machine actively refused it >>>>> >>>>> I'm on python 2.71 for windows i have jre6 se installed have set >>>>> path. cheers, Sean >>>>> >>>>> >>>>> >>>>> ----------------------------------------------------------------- >>>>> -------- >>>>> ----- >>>>> Benefiting from Server Virtualization: Beyond Initial Workload >>>>> Consolidation -- Increasing the use of server virtualization is a >>>>> top priority.Virtualization can reduce costs, simplify management, >>>>> and improve application availability and disaster protection. >>>>> Learn more about >>>>> boosting the value of server virtualization. >>>>> http://p.sf.net/sfu/vmware-sfdev2dev >>>>> _______________________________________________ >>>>> Py4j-users mailing list >>>>> Py4...@li... >>>>> https://lists.sourceforge.net/lists/listinfo/py4j-users >>>>> >>>>> >>>>> >>>> >>>> >>>> >> >> > |
