Gaurav Dasgupta
2013-Jan-16 12:32 UTC
[Rd] How to call Java main method using rJava package?
Hi, I am trying to integrate my Java program with R using rJava package. I want to execute the whole Java program from R. The main() method in my Java code calls all the other defined methods. So, I guess I have to call the main() method in .jcall. An example Java code: *class A { public static int mySum(int x, int y) { return x+y; } public static void main (String[] arg) { System.out.println("The sum is " + mySum(2, 4)); } }* I can do the following to call the mySum() method: *.jcall(obj, "I", "mySum", as.integer(2), as.integer(4))* This will give the output *6*. But can some one explain me that how exactly I can execute this program to print *The sum is 6* from R? OR how can I call the main method? I am a beginner in R. Thanks, Gaurav [[alternative HTML version deleted]]
Simon Urbanek
2013-Jan-16 15:16 UTC
[Rd] How to call Java main method using rJava package?
On Jan 16, 2013, at 7:32 AM, Gaurav Dasgupta wrote:> Hi, > > I am trying to integrate my Java program with R using rJava package. I want > to execute the whole Java program from R. The main() method in my Java code > calls all the other defined methods. So, I guess I have to call the main() > method in .jcall. > > An example Java code: > > *class A { > public static int mySum(int x, int y) { > return x+y; > } > public static void main (String[] arg) { > System.out.println("The sum is " + mySum(2, 4)); > } > }* > > I can do the following to call the mySum() method: > *.jcall(obj, "I", "mySum", as.integer(2), as.integer(4))* > This will give the output *6*. > > But can some one explain me that how exactly I can execute this program to > print *The sum is 6* from R? OR how can I call the main method?.jcall("A","V","main",.jarray(list(), "java/lang/String") But note that System.out is sent to stdout by Java so it won't output in the R console as R output so you should really avoid it. You may consider using the stats-rosuda-devel mailing list for rJava questions. Cheers, Simon> I am a beginner in R. > > Thanks, > Gaurav > > [[alternative HTML version deleted]] > > ______________________________________________ > R-devel at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > >