Where is the error message

[yudalang3]

This is my java code:

	public String launch() throws Exception {
//		Launcher.main(null);
//		Launcher4Dev.main(null);

		System.err.println("Error:" + new File("").getAbsolutePath());
		System.out.println("Output:" + new File("").getAbsolutePath());

		new InputMismatchException("fejfoejfwef").printStackTrace();

		return "Hello this is eGPS for R!";
	}

But I run it in the R:

  setLib_and_launchJVM();
  tryCatch(
    expr = {
      instance <- .jnew(launchClass)
      words <- .jcall(obj = instance, returnSig = "S", method = "launch")
      cat('The words of eGPS Java is: ', words, '\n');

    }
    ,
    Exception = function(e) {
      e$printStackTrace()
    }
  )

I can not see any error messages????

[s-u]

By default (i.e. unless setOut or setErr is used) System.out goes to stdout and System.err goes to stderr. Stack traces also go to stderr. What exactly happens with those depends on the GUI you use and any re-directs. if you run R in a shell without any re-directs then you will see both in the console:

$ R --silent
> library(rJava)
> .jinit(".")
> .jnew("Test")$launch()
Error:/private/tmp
Output:/private/tmp
java.util.InputMismatchException: fejfoejfwef
	at Test.launch(Test.java:10)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at RJavaTools.invokeMethod(RJavaTools.java:399)
[1] "Hello this is eGPS for R!"

[yudalang3]

I think I already got it, But must people use R in the Rstudio. So we can not get the error or the std.