rmaven

Execute Java’s build tools, Apache Maven, from within R. This enables users to locally install Java libraries and use them from within R, and compile Java code from source, all as part of R package development.

Installation

Released versions of rmaven are available on r-universe.

# Enable repository from terminological r-universe
options(repos = c(
  terminological = 'https://terminological.r-universe.dev',
  CRAN = 'https://cloud.r-project.org'))
  
install.packages("rmaven")

The unstable development version is available from GitHub with:

# install.packages("devtools")
devtools::install_github("terminological/rmaven")

The package assumes a Java installation is present, which is required for Maven to run. The location of the Java installation should be detected automatically, however if not if can be set as an option: e.g. options("rmaven.java_home"="/usr/lib/jvm/java-9-oracle").

Example

When using rmaven the work-flow involved in using a Java library in R is to first fetch it from the Maven repositories. The second step is to add jars from the local Maven repository to the rJava class path, and third using rJava, create an R interface to the Java class you want to use (in this case the StringUtils class). Finally you can call the static Java method, using rJava, in this case StringUtils.rotate(String s, int distance).

library(rmaven)
start_jvm()

# step 1
dynamic_classpath = resolve_dependencies(
  groupId = "org.apache.commons", 
  artifactId = "commons-lang3", 
  version="3.12.0"
)

# step 2
rJava::.jaddClassPath(dynamic_classpath)

# step 3
StringUtils = rJava::J("org.apache.commons.lang3.StringUtils")

# step 4
StringUtils$rotate("ABCDEF",3L)

Check the documentation for more examples.