add java_get_home

NAMESPACE

@@ -8,6 +8,7 @@ export(java_clear)
 export(java_download)
 export(java_env_set)
 export(java_env_unset)
+export(java_get_home)
 export(java_install)
 export(java_list)
 export(java_quick_install)

NEWS.md

@@ -6,6 +6,8 @@
 
 - New function `java_build_env_set()` that sets the environment (either temporarily in the current session or in `./.Rprofile` file of the current working directory) to build `rJava` from source on `macOS`, `Linux` and `Windows` platforms. It uses the current value of `JAVA_HOME` environment variable by default, so that it is more convenient to use after `java_quick_install()` or `use_java()` commands. After running `java_build_env_set()`, users can install `rJava` from source with `install.packages("rJava", type = "source")` without any additional configuration. However, users will still need some system dependencies, e.g. on Linux they will need: libpcre2-dev, libdeflate-dev, libzstd-dev, liblzma-dev, libbz2-dev, zlib1g-dev, libicu-dev. A system message with a suggested `apt-get` command is printed. On Windows, `Rtools` must be installed. On `macOS`, `Xcode Command Line Tools` must be installed. See the new vignette `Install 'rJava' from source` for more details.
 
+- New function `java_get_home()` to get currently set `JAVA_HOME`. This is just a shortcut to `Sys.getenv("JAVA_HOME")`, as it is faster to type and can be even faster then used with autocomplete.
+
 ## Improvements
 
 - `java_quick_install()` now also invisibly returns the path to `JAVA_HOME`.

R/java_env.R

@@ -485,3 +485,17 @@ java_env_unset <- function(
     }
   }
 }
+
+#' @title Get JAVA_HOME
+#' @description Get the current JAVA_HOME environment variable.
+#' @return The value of the JAVA_HOME environment variable.
+#' @export
+#' @examples
+#' java_get_home()
+java_get_home <- function() {
+  java_home <- Sys.getenv("JAVA_HOME", unset = NA)
+  if (is.na(java_home) || java_home == "") {
+    return("")
+  }
+  java_home
+}

_pkgdown.yml

@@ -57,6 +57,7 @@ reference:
     contents:
       - java_check_version_cmd
       - java_check_version_rjava
+      - java_get_home
   - title: "Fine-grained Control"
     desc: >
       Control every step of `Java` download, unpacking and installation

tests/testthat/test-java_env.R

@@ -0,0 +1,16 @@
+test_that("java_get_home() gets JAVA_HOME", {
+  withr::with_envvar(
+    c("JAVA_HOME" = "/path/to/java"),
+    expect_equal(java_get_home(), "/path/to/java")
+  )
+})
+
+test_that("java_get_home() returns empty string when JAVA_HOME is not set", {
+  withr::with_envvar(
+    c("JAVA_HOME" = NA),
+    {
+      Sys.unsetenv("JAVA_HOME")
+      expect_equal(java_get_home(), "")
+    }
+  )
+})