有时要为每一篇文章统计其点击次数,如果每一次浏览都要更新一次库的话,那性能在访问量很大的情况下,服务器的压力就会很大了,比较好一点的方法就是先将要更新的数据缓存起来,然后每隔一段时间再利用数据库的批量处理,批量更新库。源码如下:<wbr><br><br><br><br> CountBean.java<br><br><br><br><br><br> package<wbr>com.tot.count;<br><br><br><br><br><br> public<wbr>class<wbr>CountBean<wbr>{<br><br> private<wbr>String<wbr>countType;<br><br> int<wbr>countId;<br><br> <br><br> public<wbr>CountBean()<wbr>{}<br><br> public<wbr>void<wbr>setCountType(String<wbr>countTypes){<br><br> this.countType=countTypes;<br><br> }<br><br> public<wbr>void<wbr>setCountId(int<wbr>countIds){<br><br> this.countId=countIds;<br><br> }<br><br> public<wbr>String<wbr>getCountType(){<br><br> return<wbr>countType;<br><br> }<br><br> public<wbr>int<wbr>getCountId(){<br><br> return<wbr>countId;<br><br> }<br><br> }<br><br> CountCache.java<br><br><br><br><br><br><br><br> package<wbr>com.tot.count;<br><br> import<wbr>java.util.*;<br><br><br><br> public<wbr>class<wbr>CountCache<wbr>{<br><br> public<wbr>static<wbr>LinkedList<wbr>list=new<wbr>LinkedList();<wbr><br><br> <br><br> public<wbr>CountCache()<wbr>{}<br><br> public<wbr>static<wbr>void<wbr>add(CountBean<wbr>cb){<br><br> if(cb!=null){<br><br> list.add(cb);<br><br> }<br><br> }<br><br> }<br><br><br><br> CountControl.java<br><br><br><br> <br><br><br><br> package<wbr>com.tot.count;<br><br> import<wbr>tot.db.DBUtils;<br><br> import<wbr>java.sql.*;<br><br><br><br> public<wbr>class<wbr>CountControl{<wbr><br><br> private<wbr>static<wbr>long<wbr>lastExecuteTime=0;//上次更新时间 <br><br> private<wbr>static<wbr>long<wbr>executeSep=60000;//定义更新间隔时间,单位毫秒<br><br> <br><br> public<wbr>CountControl()<wbr>{}<br><br> public<wbr>synchronized<wbr>void<wbr>executeUpdate(){<br><br> Connection<wbr>conn=null;<br><br> PreparedStatement<wbr>ps=null;<br><br> try{<br><br> conn<wbr>=<wbr>DBUtils.getConnection();<wbr><br><br> conn.setAutoCommit(false);<br><br> ps=conn.prepareStatement("update<wbr>t_news<wbr>set<wbr>hits=hits+1<wbr>where<wbr>id=?");<br><br> for(int<wbr>i=0;i<CountCache.list.size();i++){<br><br> CountBean<wbr>cb=(CountBean)CountCache.list.getFirst();<br><br> CountCache.list.removeFirst();<wbr><br><br> ps.setInt(1,<wbr>cb.getCountId());<br><br> ps.executeUpdate();⑴<br><br> //ps.addBatch();⑵<br><br> }<br><br> //int<wbr>[]<wbr>counts<wbr>=<wbr>ps.executeBatch();⑶<br><br> conn.commit();<br><br> }catch(Exception<wbr>e){<br><br> e.printStackTrace();<br><br> }<wbr>finally{<br><br> try{<br><br> if(ps!=null)<wbr>{<br><br> ps.clearParameters();<br><br> ps.close();<br><br> ps=null;<br><br> }<br><br> }catch(SQLException<wbr>e){}<br><br> DBUtils.closeConnection(conn);<br><br> }<br><br> }<br><br> public<wbr>long<wbr>getLast(){<br><br> return<wbr>lastExecuteTime;<br><br> }<br><br> public<wbr>void<wbr>run(){<br><br> long<wbr>now<wbr>=<wbr>System.currentTimeMillis();<br><br> if<wbr>((now<wbr>-<wbr>lastExecuteTime)<wbr>><wbr>executeSep)<wbr>{<br><br> //System.out.print("lastExecuteTime:"+lastExecuteTime);<br><br> //System.out.print("<wbr>now:"+now+"\n");<br><br> //<wbr>System.out.print("<wbr>sep="+(now<wbr>-<wbr>lastExecuteTime)+"\n");<br><br> lastExecuteTime=now;<br><br> executeUpdate();<br><br> }<br><br> else{<br><br> //System.out.print("wait<wbr>for<wbr>"+(now<wbr>-<wbr>lastExecuteTime)+"<wbr>seconds:"+"\n");<br><br> }<br><br> }<br><br> }<br><br> //注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释<br><br> 类写好了,下面是在JSP中如下调用。<br><br><br><br> <%<br><br> CountBean<wbr>cb=new<wbr>CountBean();<br><br> cb.setCountId(Integer.parseInt(request.getParameter("cid")));<br><br> CountCache.add(cb);<br><br> out.print(CountCache.list.size()+"<br>");<br><br> CountControl<wbr>c=new<wbr>CountControl();<br><br> c.run();<br><br> out.print(CountCache.list.size()+"<br>");<br><br> %><br><wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>