How to execute a R script file from java

Question

I would like to call an R script from Java. I have done google searches on the topic, but almost all of the results I have seen would require me to add a dependency to some third party library. Can anyone show me a good way to accomplish the same thing without adding any dependencies to my code?

I'm setting up a new application which runs R script file from java using the following line

Runtime.getRuntime().exec("C:\\Users\\Thiru\\Desktop helloWorld.R");

but when I run the application I am getting following exception:

SEVERE: Servlet.service() for servlet [RenjinServlet] in context with 
path 
[/REngineCheck] threw exception
java.io.IOException: Cannot run program "C:\Users\Thiru\Desktop": 
CreateProcess error=5, Access is denied
at java.lang.ProcessBuilder.start(Unknown Source)
at java.lang.Runtime.exec(Unknown Source)
at java.lang.Runtime.exec(Unknown Source)
at java.lang.Runtime.exec(Unknown Source)
at org.r.Check.RenjinServlet.doGet(RenjinServlet.java:102)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at 

org.apache.catalina.core.ApplicationFilterChain.internalDoFilter 
(ApplicationFilterChain.java:291)
at 
org.apache.catalina.core.ApplicationFilterChain.doFilter
(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter (WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter 
(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter 
(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke 
(StandardWrapperValve.java:217)
at org.apache.catalina.core.StandardContextValve.invoke 
(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke 
(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke 
(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke 
(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke 
(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke 
(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service 
(CoyoteAdapter.java:518)
at org.apache.coyote.http11.AbstractHttp11Processor.process 
(AbstractHttp11Processor.java:1091)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process 
(AbstractProtocol.java:673)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun 
(NioEndpoint.java:1500)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run 
 (NioEndpoint.java:1456)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run 
  (TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
Caused by: java.io.IOException: CreateProcess error=5, Access is denied
at java.lang.ProcessImpl.create(Native Method)
at java.lang.ProcessImpl.<init>(Unknown Source)
at java.lang.ProcessImpl.start(Unknown Source)
... 28 more

Answer 1

You should set up your path in a bracket like

("your_path\Rscript.exe your_path\filename.R")

If you set the environment, you can use Rscript

Example:

Runtime.getRuntime().exec("C:\\Program Files\\R\\R-3.6.1\\bin\\x64\\Rscript.exe C:\\Users\\Thiru\\Desktop\\helloWorld.R");