rJava (version 0.4-3)

jarray: Creates a Java array from a vector

Description

.jarray takes a vector (or a list of Java references) as its argument, creates a Java array containing the elements of the vector (or list) and returns a reference to such newly created array.

Usage

.jarray(x, contents.class = NULL)

Arguments

x

vector or a list of Java references

contents.class

common class of the contained objects, see details

Value

• Returns a Java object reference (jobjRef) of a null object having the specified object class.

Details

The input can be either a vector of some sort (such as numeric, integer, logical, ...) or a list of Java references. The contents is pushed to the Java side and a corresponding array is created. The type of the array depends on the input vector type. For example numeric vector creates double[] array, integer vector creates int[] array, character vector String[] array and so on. If x is a list, it must contain Java references only (or NULLs which will be treaded as NULL references).

The contents.class parameter is used only if x is a list of Java object references and it can specify the class that will be used for all objects in the array. If set to NULL no assumption is made and java/lang/Object will be used. Use with care and only if you know what you're doing - you can always use .jcast to cast the entire array to another type even if you use a more general object type.

The result is a reference to the newly created array.

The inverse function which fetches the elements of an array reference is .jevalArray.

Examples

a <- .jarray(1:10)
a
.jevalArray(a)
b <- .jarray(c("hello","world"))
b
c <- .jarray(list(a,b))
c