added storage adapter

lib/weixin_authorize/adapter/storage.rb

+# encoding: utf-8
+module WeixinAuthorize
+
+  class Storage
+
+    attr_accessor :storage
+
+    def initialize(storage)
+      @storage = storage
+    end
+
+    def self.init_with(storage)
+      if storage.is_a? Client
+        ObjectStorage.new(storage)
+      else
+        RedisStorage.new(storage)
+      end
+    end
+
+    def valid?
+      raise NotImplementedError, "Subclasses must implement a valid? method"
+    end
+
+    def token_expired?
+      raise NotImplementedError, "Subclasses must implement a token_expired? method"
+    end
+
+    def authenticate
+      raise NotImplementedError, "Subclasses must implement a authenticate method"
+    end
+
+    def get_access_token
+
+    end
+  end
+
+  class RedisStorage < Storage
+
+    def valid?
+     storage.del(storage.redis_key)
+    end
+
+    def token_expired?
+      storage.hvals(redis_key).empty?
+    end
+
+    def authenticate
+
+    end
+
+  end
+
+  class ObjectStorage < Storage
+
+    def valid?
+
+    end
+
+    def token_expired?
+      # 如果当前token过期时间小于现在的时间，则重新获取一次
+      stoage.expired_at <= Time.now.to_i
+    end
+
+    def authenticate
+
+    end
+  end
+
+end