This is documentation for Mathematica 7, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.1)

InstallJava

InstallJava[]
launches the Java runtime and prepares it to be used from Mathematica.
  • Only one Java runtime is ever launched; subsequent calls to InstallJava after the first have no effect.
  • The following options can be given:
ClassPathAutomaticuse the specified directories and .jar files
CommandLineAutomaticspecify a command line to launch the JVM