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. Configure Java before loading rJava, including before requireNamespace("rJava") or loading packages that import it. Loading the namespace can resolve and lock the JVM library path even before .jinit() starts the JVM. See https://github.com/s-u/rJava/issues/334 and https://github.com/s-u/rJava/issues/25.

Once rJava has loaded, restart R before selecting another JVM, or use with_rjava_env() to run with a different JVM in a fresh R process. java_check_compatibility() does not load rJava or initialize a JVM. java_check_version_rjava() performs its probe in a separate R process.

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: native-amazon-corretto-17.0.21.0.11-linux-x64.tar.gz
java_home <- java_install(
  java_distrib_path = java_17_distrib,
  project_path = tempdir(),
  autoset_java_env = FALSE
)
#> Java distribution native-amazon-corretto-17.0.21.0.11-linux-x64.tar.gz already
#> unpacked at
#> /home/runner/.cache/R/rJavaEnv/installed/linux/x64/Corretto/native/17
#> Java 17 (native-amazon-corretto-17.0.21.0.11-linux-x64.tar.gz) for linux x64
#> installed at
#> /home/runner/.cache/R/rJavaEnv/installed/linux/x64/Corretto/native/17 and
#> symlinked to /tmp/Rtmp7ZJxYe/rjavaenv/linux/x64/Corretto/native/17

# 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.Loading rJava can lock the JVM library path even before .jinit() starts the JVM.Set Java before loading rJava. To change its JVM, restart R or use `with_rjava_env()`.See https://github.com/s-u/rJava/issues/334
#> ✔ 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/Rtmp7ZJxYe'
#> 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`

# }