# File lib/jmx4r.rb, line 129
    def self.connection(args={})
      if args.has_key? :host or args.has_key? :port
        return create_connection(args)
      else
        @@connection ||= MBean.establish_connection(args)
      end
    end

# File lib/jmx4r.rb, line 163
    def self.create_connection(args={})
      host= args[:host] || "localhost"
      port = args[:port] || 3000
      username = args[:username]
      password = args[:password]
      credentials = args[:credentials]
      provider_package = args[:provider_package]
      
      # host & port are not taken into account if url is set (see issue #7)
      standard_url = "service:jmx:rmi:///jndi/rmi://#{host}:#{port}/jmxrmi"
      url = args[:url] || standard_url
      
      unless credentials
        if !username.nil? and username.length > 0
          user_password_credentials = [username, password]
          credentials = user_password_credentials.to_java(:String)
        end
      end
      
      env = HashMap.new
      env.put(JMXConnector::CREDENTIALS, credentials) if credentials
      # only fill the Context and JMXConnectorFactory properties if provider_package is set
      if provider_package
        env.put(Context::SECURITY_PRINCIPAL, username) if username
        env.put(Context::SECURITY_CREDENTIALS, password) if password
        env.put(JMXConnectorFactory::PROTOCOL_PROVIDER_PACKAGES, provider_package)
      end

      # the context class loader is set to JRuby's classloader when
      # creating the JMX Connection so that classes loaded using 
      # JRuby "require" (and not from its classpath) can also be 
      # accessed (see issue #6)
      begin
        context_class_loader = JThread.current_thread.context_class_loader
        JThread.current_thread.context_class_loader = JRuby.runtime.getJRubyClassLoader
        
        connector = JMXConnectorFactory::connect JMXServiceURL.new(url), env
        MBeanServerConnectionProxy.new connector
      ensure
        # ... and we reset the previous context class loader
        JThread.current_thread.context_class_loader = context_class_loader
      end
    end

# File lib/jmx4r.rb, line 118
    def self.establish_connection(args={})
      @@connection ||= create_connection args
    end

# File lib/jmx4r.rb, line 218
    def self.find_all_by_name(name, args={})
      object_name = ObjectName.new(name)
      connection = args[:connection] || MBean.connection(args)
      object_names = connection.queryNames(object_name, nil)
      object_names.map { |on| MBean.new(on, connection) }
    end

# File lib/jmx4r.rb, line 228
    def self.find_by_name(name, args={})
      connection = args[:connection] || MBean.connection(args)
      MBean.new ObjectName.new(name), connection
    end

# File lib/jmx4r.rb, line 66
    def initialize(object_name, connection=nil)
      @connection = connection || @@connection
      @object_name = object_name
      info = @connection.getMBeanInfo @object_name
      @attributes = Hash.new
      info.attributes.each do | mbean_attr |
        @attributes[mbean_attr.name.snake_case] = mbean_attr.name
        self.class.instance_eval do 
          define_method mbean_attr.name.snake_case do
            @connection.getAttribute @object_name, "#{mbean_attr.name}"
          end
        end
        if mbean_attr.isWritable
          self.class.instance_eval do
            define_method "#{mbean_attr.name.snake_case}=" do |value| 
              attr = Attribute.new mbean_attr.name, value
              @connection.setAttribute @object_name, attr
            end
          end
        end
      end
      @operations = Hash.new
      info.operations.each do |mbean_op|
        param_types = mbean_op.signature.map {|param| param.type}
        @operations[mbean_op.name.snake_case] = [mbean_op.name, param_types]
      end
    end

# File lib/jmx4r.rb, line 233
    def self.pretty_print (object_name, args={})
      connection = args[:connection] || MBean.connection(args)
      info = connection.getMBeanInfo ObjectName.new(object_name)
      puts "object_name: #{object_name}"
      puts "class: #{info.class_name}"
      puts "description: #{info.description}"
      puts "operations:"
      info.operations.each do | op |
        puts "  #{op.name}"
        op.signature.each do | param |
          puts "    #{param.name} (#{param.type} #{param.description})"
        end
        puts "    ----"
        puts "    description: #{op.description}"
        puts "    return_type: #{op.return_type}"
        puts "    impact: #{op.impact}"
      end
      puts "attributes:"
      info.attributes.each do | attr |
        puts "  #{attr.name}"
        puts "    description: #{attr.description}"
        puts "    type: #{attr.type}"
        puts "    readable: #{attr.readable}"
        puts "    writable: #{attr.writable}"
        puts "    is: #{attr.is}"
      end
    end

# File lib/jmx4r.rb, line 122
    def self.remove_connection(args={})
      if @@connection
        @@connection.close rescue nil
      end
      @@connection = nil
    end