rtika (version 1.23)

java: System Command to Run Java

Description

Gets the system command needed to run Java from the command line, as a string. Typically, this is the string: 'java'. However, if the R session has the JAVA_HOME environmental variable set, it will use that to locate java instead. This can be persisted over sessions (see the Details below).

Usage

java()

Value

The system command needed to invoke Java, as a string.

Details

This function is used by all of the tika() functions internally as the default value to its java parameter.

This function tries to find an environmental variable using Sys.getenv("JAVA_HOME"). It looks for the java executable inside the bin directory in the JAVA_HOME directory.

If you want to use a specific version of Java, set the JAVA_HOME variable using Sys.setenv(JAVA_HOME = 'my path'), where 'my path' is the path to a folder that has a bin directory with a java executable.

For example, on Windows 10 JAVA_HOME might be C:/Program Files (x86)/Java/jre1.8.0_171. On Ubuntu and OS X, it might be the /usr directory.

The JAVA_HOME variable can also be set to persist over sessions. Add the path to the .Rprofile by adding Sys.setenv(JAVA_HOME = 'my path'), and it will use that every time R is started.

Examples

# NOT RUN {
# Typically, this function returns the string 'java'.
# If JAVA_HOME is set, it's a path to java in a 'bin' folder.
java()
# }