Set current jvm

select_jvm.rb

#!/usr/bin/env jruby

require 'java'
JVMS = ["/home/sebastien/dev/jdk1.6.0_25",
        "/home/sebastien/dev/jdk1.6.0_30",
        "/home/sebastien/dev/jdk1.7.0_02"]


current_java_home = ENV['JAVA_HOME']
if ARGV.size != 1 
  puts "Usage: select_jvm.rb <number>"
  exit
end

arg = ARGV[0]
if arg == "--help" || arg == "-h"
  puts "Usage: select_jvm.rb <number>"
  puts "List of JVMs:"
  JVMS.each_with_index do |jvm, index|
    puts "#{index+1}) #{jvm}"
  end
else
  selection = ARGV[0].to_i-1
  selected_jvm = JVMS[selection]
  if selected_jvm != current_java_home
    current_path = ENV['PATH']
    ENV['PATH'] = current_path.gsub(File.join(current_java_home, 'bin'), File.join(selected_jvm, 'bin'))
    ENV['JAVA_HOME'] = selected_jvm
  end
end

`java -version`