state.rb

# state.rb 状态模式
class Connection
  attr_accessor :state
  def initialize
    @state = TCPClose.new
  end

  def reset
    @state = TCPClose.new
  end

  def disconnect
    state.disconnect(self)
  end

  def connect
    state.connect(self)
  end

end

class TCPOpen
  def disconnect(tcp)
    puts "正在断开"
    tcp.state = TCPClose.new
  end

  def connect(tcp)
    puts "已经连着了, 不用再连"
  end
end

class TCPClose
  def disconnect(tcp)
    puts "根本就没连上"
  end

  def connect(tcp)
    puts "正在连接"
    tcp.state = TCPOpen.new
  end
end


if __FILE__ == $0
    c = Connection.new
    c.disconnect
    c.connect
    c.connect
    c.disconnect
    c.connect
    c.reset
    c.disconnect
end

=begin

根本就没连上
正在连接
已经连着了, 不用再连
正在断开
正在连接
根本就没连上

=end