JRuby programs

InternationalizationEx.java

import java.util.*;
public class InternationalizationEx
{
  public static void main(String[] args)
  {
    String lang, country;
    Locale cLocale;
    ResourceBundle msg;

    lang = new String("de");
    country = new String("DE");

    cLocale = new Locale(lang, country);
    msg = ResourceBundle.getBundle("MessagesBundle", cLocale);

    System.out.println(msg.getString("greetings"));
    System.out.println(msg.getString("welcome"));
  }
}

jruby04.rb

require 'java'
java_import java.lang.System
puts System.get_property("os.name")

jruby05.rb

require 'java'
java_import 'java.lang.String' do |package,name|
  "J#{name}"
end

ResourceBundle = java.util.ResourceBundle
Locale = java.util.Locale

lang = JString.new 'de'
country = JString.new 'DE'

cLocale = Locale.new lang, country
msg = ResourceBundle.get_bundle 'MessagesBundle', cLocale

puts msg.get_string 'greetings'
puts msg.get_string 'welcome'

jruby05m.rb

require 'java'
java_import('java.lang.String') do |package,name|
  "J#{name}"
end

ResourceBundle = java.util.ResourceBundle
Locale = java.util.Locale

lang = JString.new 'pt'
country = JString.new 'BR'

cLocale = Locale.new lang, country
msg = ResourceBundle.get_bundle 'MessagesBundle', cLocale

puts msg.get_string 'greetings'
puts msg.get_string 'welcome'

jruby06.rb

require 'java'
JFrame = javax.swing.JFrame  
JLabel = javax.swing.JLabel  
frame  = JFrame.new  
jlabel = JLabel.new 'Hello World'  
frame.add jlabel
frame.set_default_close_operation JFrame::EXIT_ON_CLOSE
frame.pack
frame.set_size 200, 200
frame.set_visible true

jruby07.rb

# Extending a Java class
class MyButtons < Java::java.awt.Frame
  def initialize(title)
    super(title)
    button = Java::java.awt.Button.new('OK')
    panel = Java::java.awt.Panel.new
    panel.add(button)
    button.add_action_listener ClickAction.new
    add(panel, Java::java.awt.BorderLayout::SOUTH)
    set_visible(true)
  end
end

class ClickAction 
  # Implementing a Java interface
  include Java::java.awt.event.ActionListener
  
  def actionPerformed(e)
    puts 'Button is Pressed'
  end
end

mb = MyButtons.new('Sample Swing app')