Problem passing String[][] from Java to R using rJava

Question

Is it possible to return from Java a String[][] to R using rJava?

I call the method

public String[][] readFromTable(String tableName, String security,
        String[] fields, String startTime, String endTime, boolean reverse)

from R with

   out <- .jcall(obj, "[[S", "readFromTable", tableName, security, .jarray(fields),
    start, end, reverse)

When I change the return type of the method to String[] everything works just fine, I experimented with the parameters and I am pretty sure that the problem is the String[][].

Has anyone got an idea?

EDIT 1:
Sorry, I forgot the error message:
Error in .jcall(obj, "[[S", "readFromTable", tableName, security, .jarray(fields), : method readFromTable with signature (Ljava/lang/String;Ljava/lang/String;[Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Z)[[S not found

EDIT 2
I just figured out that it works if I return a Double[][]...so maybe there is a bug in the String JNI implementation in the rJava package but that's hard to believe

I also tried it with [[Ljava/lang/String instead of [[S but that does not work either... — Tobi
– Tobi, Commented Aug 30, 2011 at 15:06

Vineeth Mohan · Accepted Answer · 2012-09-17 12:20:03Z

1

[[Ljava/lang/String;

This will work

answered Sep 17, 2012 at 12:20

Vineeth Mohan

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Comments

Matthias · Accepted Answer · 2012-06-06 14:55:39Z

0

Have you tried to play with the .jarray? It was an issue of my problems.

.jarray(fields, contents.class="Ljava/lang/String")

edited Jun 6, 2012 at 14:55

Matthias

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answered Jun 6, 2012 at 12:39

Drey

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