function asdf_update_java_home --on-event fish_prompt
  set --local java_path (asdf which java)
  if test -n "$java_path"
    set --local full_path (builtin realpath "$java_path")
    
    # `builtin realpath` returns $JAVA_HOME/bin/java, so we need two `dirname` calls
    # in order to get the correct JAVA_HOME directory
    set -gx JAVA_HOME (dirname (dirname "$full_path"))
    set -gx JDK_HOME "$JAVA_HOME"
  end
end