Set the JAVA_HOME and PATH environment variables to a given path

Sets the JAVA_HOME and PATH environment variables for command-line Java tools and rJava initialization. See details for important information about rJava timing.

Usage

java_env_set(
  where = c("session", "both", "project"),
  java_home,
  project_path = NULL,
  quiet = FALSE
)

Arguments

where: Where to set the JAVA_HOME: "session", "project", or "both". Defaults to "session" and only updates the paths in the current R session. When "both" or "project" is selected, the function updates the .Rprofile file in the project directory to set the JAVA_HOME and PATH environment variables at the start of the R session.
java_home: The path to the desired JAVA_HOME.
project_path: A character vector of length 1 containing the project directory where Java should be installed. If not specified or NULL, defaults to the current working directory.
quiet: A logical value indicating whether to suppress messages. Can be TRUE or FALSE.

Value

Nothing. Sets the JAVA_HOME and PATH environment variables.

Additional Details

To use a different Java version with rJava-dependent packages, you must:

Set JAVA_HOME using this function BEFORE loading rJava or any package that imports it
Restart your R session if you already loaded rJava with the wrong Java version

rJava Path-Locking

Important for rJava Users: This function sets environment variables (JAVA_HOME, PATH) that affect both command-line Java tools and rJava initialization. However, due to rJava's path-locking behavior when .jinit is called (see https://github.com/s-u/rJava/issues/25, https://github.com/s-u/rJava/issues/249, and https://github.com/s-u/rJava/issues/334), this function must be called BEFORE .jinit is invoked. Once .jinit initializes, the Java version is locked for that R session and cannot be changed without restarting R.

.jinit is invoked (and Java locked) when you:

Explicitly call library(rJava)
Load any package that imports rJava (which auto-loads it as a dependency)
Even just use IDE autocomplete with rJava:: (this triggers initialization!)
Call any rJava-dependent function

Once any of these happen, the Java version used by rJava for that session is locked in. For command-line Java tools that don't use rJava, this function can be called at any time to switch Java versions for subsequent system calls.

Examples

# \donttest{
# download, install Java 17
java_17_distrib <- java_download(version = "17", temp_dir = TRUE)
#> Detected platform: linux
#> Detected architecture: x64
#> You can change the platform and architecture by specifying the `platform` and
#> `arch` arguments.
#> File already cached: amazon-corretto-17.0.17.10.1-linux-x64.tar.gz
java_home <- java_install(
  java_distrib_path = java_17_distrib,
  project_path = tempdir(),
  autoset_java_env = FALSE
)
#> Java distribution amazon-corretto-17.0.17.10.1-linux-x64.tar.gz already
#> unpacked at
#> /home/runner/.cache/R/rJavaEnv/installed/linux/x64/Corretto/native/17
#> Java NA (amazon-corretto-17.0.17.10.1-linux-x64.tar.gz) for linux x64 installed
#> at /home/runner/.cache/R/rJavaEnv/installed/linux/x64/Corretto/native/17 and
#> symlinked to /tmp/RtmpBxf86B/rjavaenv/linux/x64/Corretto/native/NA

# now manually set the JAVA_HOME and PATH environment variables in current session
java_env_set(
  where = "session",
  java_home = java_home
)
#> ℹ You have rJava loaded in the current session. rJava gets locked to the Java version that was active when it was first initialized.rJava is initialized when you: (1) call `library(rJava)`, (2) load a package that imports rJava, (3) use IDE autocomplete with `rJava::`, or (4) call any rJava function.This path-locking is a limitation of rJava itself. See: https://github.com/s-u/rJava/issues/25, https://github.com/s-u/rJava/issues/249, and https://github.com/s-u/rJava/issues/334Unless you restart the R session or run your code in a new R subprocess (using targets or callr), the new `JAVA_HOME` and `PATH` will not take effect.
#> ✔ Current R Session: JAVA_HOME and PATH set to /home/runner/.cache/R/rJavaEnv/installed/linux/x64/Corretto/native/17
#> ℹ On Linux, for rJava to work correctly, `libjvm.so` was dynamically loaded in
#>   the current session.
#>   To make this change permanent for installing rJava-dependent packages from
#>   source, you may need to reconfigure Java.
#>   See <https://solutions.posit.co/envs-pkgs/using-rjava/#reconfigure-r> for
#>   details.
#>   If you have admin rights, run the following in your terminal:
#>   `R CMD javareconf
#>   JAVA_HOME=/home/runner/.cache/R/rJavaEnv/installed/linux/x64/Corretto/native/17`
#>   If you do not have admin rights, run:
#>   `R CMD javareconf
#>   JAVA_HOME=/home/runner/.cache/R/rJavaEnv/installed/linux/x64/Corretto/native/17
#>   -e`

# or set JAVA_HOME and PATH in the spefific projects' .Rprofile
java_env_set(
  where = "project",
  java_home = java_home,
  project_path = tempdir()
)
#> ✔ Current R Project/Working Directory: JAVA_HOME and PATH set to '/home/runner/.cache/R/rJavaEnv/installed/linux/x64/Corretto/native/17' in .Rprofile at '/tmp/RtmpBxf86B'
#> ℹ On Linux, for rJava to work correctly, `libjvm.so` was dynamically loaded in
#>   the current session.
#>   To make this change permanent for installing rJava-dependent packages from
#>   source, you may need to reconfigure Java.
#>   See <https://solutions.posit.co/envs-pkgs/using-rjava/#reconfigure-r> for
#>   details.
#>   If you have admin rights, run the following in your terminal:
#>   `R CMD javareconf
#>   JAVA_HOME=/home/runner/.cache/R/rJavaEnv/installed/linux/x64/Corretto/native/17`
#>   If you do not have admin rights, run:
#>   `R CMD javareconf
#>   JAVA_HOME=/home/runner/.cache/R/rJavaEnv/installed/linux/x64/Corretto/native/17
#>   -e`

# }