diff --git a/app/helpers/system_log_helper.rb b/app/helpers/system_log_helper.rb
new file mode 100644
index 000000000..4528143ef
--- /dev/null
+++ b/app/helpers/system_log_helper.rb
@@ -0,0 +1,57 @@
+module SystemLogHelper
+    class SystemLog
+      class << self
+        # 分页（支持多关键字查询）
+        def logo_data(page,per,search)
+          logs = find_all_logs
+
+          # 根据search参数来决定是否需要查询
+          keywords = search
+          if keywords && !keywords.strip.blank?
+            # 把keywords转化成正则表达式数组
+            keywords = keywords.strip.split(/\s+/).collect! {|w| Regexp.new(w, 'i')}
+            # 一条记录应该匹配每个关键字
+            logs = logs.find_all do |log|
+              keywords.all? { |r| log =~ r }
+            end
+            logs = Kaminari.paginate_array(logs).page(page).per(per).collect! {|log| parse(log)}
+            logs.collect! do |log|
+              keywords.each { |r| log.gsub!(r, '<span class="search_results">\0</span>')}
+              log
+            end
+          else
+            logs = Kaminari.paginate_array(logs).page(page).per(per).collect! {|log| parse(log)}
+          end
+          logs
+        end
+
+        #清除日誌
+        def clear
+          File.open(logfile_path, 'w') do |f|
+            f.print ''
+          end
+        end
+
+        #讀取日誌
+        private
+        def find_all_logs
+          File.open(logfile_path) do |f|
+            #打开文件，并按照正则表达式切分，逆序，最新一个记录可以扔掉（因为最新的记录永远都是访问System_log)
+            f.read.split("Processing").reverse[1..-1]
+          end
+        end
+
+        # 日志文件的路径，一般在Rails.root/log下，根据环境配置
+        # 依次记录到product.log development.log test.log中
+        def logfile_path
+          File.join(Rails.root, "log", "#{Rails.env}.log")
+        end
+
+        #替換換行符
+        def parse(log)
+          ERB::Util.html_escape(log.gsub(/\e\[[\d;m]+/, '')).gsub("\n", "<br/>")
+        end
+      end
+    end
+  end
+
diff --git a/app/models/document.rb b/app/models/document.rb
index e2e0a8d00..48a0151eb 100644
--- a/app/models/document.rb
+++ b/app/models/document.rb
@@ -81,7 +81,5 @@ class Document < ActiveRecord::Base
     update_document(self.user,2,self.project)
   end
 
-  def expire_cache
-    ActionController::Base.new.expire_fragment('activities')
-  end
+
 end