In petermeissner/javahelloworld: Minimal and Toy Example of some Java Code Packaged up for R

github_user_name   <- "petermeissner"
codecov_user_name  <- github_user_name
travis_user_name   <- github_user_name
appveyor_user_name <- github_user_name

knitr::opts_chunk$set(
  fig.path = "man/figures/README-"
)

options("width"=110)

# get package info
tmp <- packageDescription( "javahelloworld" )
#tmp <- packageDescription( basename(getwd()) )

package_name <- tmp$Package

cat("#", tmp$Title)

Status

filelist.R   <- list.files("R", recursive = TRUE, pattern="\\.R$", ignore.case = TRUE, full.names = TRUE)
filelist.tests   <- list.files("tests", recursive = TRUE, pattern="\\.R$", ignore.case = TRUE, full.names = TRUE)
filelist.cpp <- list.files("src", recursive = TRUE, pattern="\\.cpp$", ignore.case = TRUE, full.names = TRUE)
lines.R      <- unlist(lapply(filelist.R, readLines))
lines.tests  <- unlist(lapply(filelist.tests, readLines))
lines.cpp    <- unlist(lapply(filelist.cpp, readLines))
length.R     <- length(grep("(^\\s*$)|(^\\s*#)|(^\\s*//)", lines.R,  value = TRUE, invert = TRUE))
length.tests <- length(grep("(^\\s*$)|(^\\s*#)|(^\\s*//)", lines.tests,  value = TRUE, invert = TRUE))
length.cpp   <- length(grep("(^\\s*$)|(^\\s*#)|(^\\s*//)", lines.cpp,  value = TRUE, invert = TRUE))

lines of R code: r length.R, lines of test code: r length.tests

Version

source_files <-
  grep(
    "/R/|/src/|/tests/",
    list.files(recursive = TRUE, full.names = TRUE),
    value = TRUE
  )
last_change <-
  as.character(
    format(max(file.info(source_files)$mtime), tz="UTC")
  )

cat(tmp$Version, "(",last_change,")")

Description

cat(tmp$Description)

License

cat(tmp$License, "<br>")
cat(tmp$Author)

Citation

cat("```r\n")
cat("citation(\"",package_name,"\")", sep = "")
cat("\n```\n")

cat("```r\n")
print_text <- capture.output(print(citation(package_name), style = "text"))
cat(gsub("_", "", print_text))
cat("\n```\n")

BibTex for citing

cat("```r\n")
cat("toBibtex(citation(\"",package_name,"\"))", sep = "")
cat("\n```\n")

cat("```\n")
cat(as.character(toBibtex(citation(package_name))), sep = "\n")
cat("\n```\n")

Installation

Stable version from CRAN:

cat("```r\n")
cat("install.packages(\"",package_name,"\")", sep = "")
cat("\n```\n")

Usage

starting up

library(javahelloworld)

calling Java?

test_method_call

let it run

test_method_call

How To Build an R/Java Package

• make R package
• install/use default maven (+ e.g. VSCode)
• add on.load function with rJava initialization to zzz.R file
• DESCRIPTION SystemRequirements: Java
• source: https://cran.r-project.org/web/packages/helloJavaWorld/index.html
• source: https://cran.r-project.org/web/packages/helloJavaWorld/vignettes/helloJavaWorld.pdf
• fix path and JAVA_HOME until package builds
• add package path to maven pom file
• add Java wrapper to R package
• ?Control Logging?:
• https://docs.oracle.com/javase/7/docs/api/java/util/logging/LogManager.html
• https://github.com/hrbrmstr/htmlunitjars/blob/master/R/logging.r

petermeissner/javahelloworld documentation built on Oct. 18, 2020, 8:35 p.m.