rJava: jreflection – R documentation

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jreflection

Simple helper functions for Java reflection

Description

.jconstructors returns a character vector with all constructors for a given class or object. .jmethods returns a character vector with all methods for a given class or object. .jfields returns a character vector with all fields (aka attributes) for a given class or object.

Usage

.jconstructors(o, as.obj = FALSE, class.loader=.rJava.class.loader)
.jmethods(o, name = NULL, as.obj = FALSE, class.loader=.rJava.class.loader)
.jfields(o, name = NULL, as.obj = FALSE, class.loader=.rJava.class.loader)

Arguments

`o`	Name of a class (either notation is fine) or an object whose class will be queried
`name`	string, regular expression of the method/field to look for
`as.obj`	if `TRUE` then a list of Java objects is returned, otherwise a character vector (obtained by calling `toString()` on each entry).
`class.loader`	optional, class loader to use for class look up if needed (i.e., if `o` is a string)

Details

There first two functions are intended to help with finding correct signatures for methods and constructors. Since the low-level API in rJava doesn't use reflection automatically, it is necessary to provide a proper signature. That is somewhat easier using the above methods.

Value

Returns a character vector (if as.obj is FALSE) or a list of Java objects. Each entry corresponds to the Constructor resp. Method resp. Field object. The string result is constructed by calling toString() on the objects.

Examples

## Not run: 
.jconstructors("java.util.Vector")
v <- .jnew("java.util.Vector")
.jmethods(v, "add")

## End(Not run)

rJava

Low-Level R to Java Interface

v1.0-4

LGPL-2.1

Authors

Simon Urbanek <simon.urbanek@r-project.org>

Initial release