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: /qEoiL###
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CountBean.java iq=<LOx
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/* eNpGa0 eG
* CountData.java fC52nK&T8
* 3`$-
* Created on 2007年1月1日, 下午4:44 dk# LAm0<
* BH0].-)[y!
* To change this template, choose Tools | Options and locate the template under G)G5eXXX
* the Source Creation and Management node. Right-click the template and choose {+!m]-s
* Open. You can then make changes to the template in the Source Editor. Ak^g#^c*
*/ 8 YsDE_
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package com.tot.count; ]:8:|*w
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/** ??Q'| r
* =E,^ +`M
* @author TDq(%IW
*/ n3-5`Jti
public class CountBean { 2c
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private String countType; l`M{Ravvn*
int countId; sFuB[
JJ}
/** Creates a new instance of CountData */ gDa}8!+i
public CountBean() {} N^jQ\|A<
public void setCountType(String countTypes){ Tq,Kel
this.countType=countTypes; bk44qL;8
} y yW;VKN
public void setCountId(int countIds){ DY/xBwIF
this.countId=countIds; h(l4\)
} "AMbU68
public String getCountType(){ f.-b.nNf
return countType; YzNSZJPD
} Z9,-FO{#3-
public int getCountId(){ a<*q+a(*W
return countId; |C"(K-do
} !Lkk1zo
} rO4R6A
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CountCache.java D]tI's1
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/* k4T`{s}e
* CountCache.java gI~B _0x
* cPunMHD
* Created on 2007年1月1日, 下午5:01 !U::kr=t
* (E(J}r~E
* To change this template, choose Tools | Options and locate the template under >ElK8
* the Source Creation and Management node. Right-click the template and choose 2 nra@
* Open. You can then make changes to the template in the Source Editor. 0nr 5(4h
*/ POXd ,ON9
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package com.tot.count; ) KvGJo)("
import java.util.*; C*X=nezq
/** P*6h$T
* G]v BI=
* @author R<djW5 ()f
*/ p C^=?!:U
public class CountCache { Tfq7<<0$N
public static LinkedList list=new LinkedList(); WU$l@:Yo
/** Creates a new instance of CountCache */ @bRKJPU9)
public CountCache() {} #nq$^H
public static void add(CountBean cb){ $U=j<^R}a
if(cb!=null){ %fuV]
list.add(cb);
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} '2z1$zst,#
} ]Z IreI
} *3iEO>
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CountControl.java mV'-1
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/* 6%^A6U
* CountThread.java .QU]
* u']}Z%A9`
* Created on 2007年1月1日, 下午4:57 DuQW?9^232
* 3ncN)E/@
* To change this template, choose Tools | Options and locate the template under =f?vpKq40
* the Source Creation and Management node. Right-click the template and choose 9ls*L!Jw
* Open. You can then make changes to the template in the Source Editor. cY^'Cj
*/ "IHFme@^
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package com.tot.count; XEBeoOX/
import tot.db.DBUtils; 'iWDYZ?
import java.sql.*; x,NV{uG$n
/** -K (>uV!?
* mCe"=[
* @author kGmz1S}2
*/ yUjkRT&h
public class CountControl{ Q7#t#XM
private static long lastExecuteTime=0;//上次更新时间 XL7||9,(h
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ]f~!Qk!I7r
/** Creates a new instance of CountThread */ gNJdP!(t
public CountControl() {} (_]!}N
public synchronized void executeUpdate(){ M0g=gmau
Connection conn=null; -u7NBtgUh
PreparedStatement ps=null; P4zwTEk`
try{ h@z0 x4_])
conn = DBUtils.getConnection(); l<p<\,nV$
conn.setAutoCommit(false); 5$$#d_Gj
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); artn _
for(int i=0;i<CountCache.list.size();i++){ +f%"O?
CountBean cb=(CountBean)CountCache.list.getFirst(); p6aR/gFkqv
CountCache.list.removeFirst(); +$Y*1{hyOo
ps.setInt(1, cb.getCountId()); XjdHH.) S
ps.executeUpdate();⑴ dVk(R9 8
//ps.addBatch();⑵ f[
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} {kBsiSvsA;
//int [] counts = ps.executeBatch();⑶ 0@[*~H0{n
conn.commit(); ,
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}catch(Exception e){ xHqF_10S#
e.printStackTrace();
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} finally{ 4l{$dtKbI
try{ Bd7B\zM
if(ps!=null) { RO|8NC<oj
ps.clearParameters(); PxQQf I>
ps.close(); rHM^_sYRb
ps=null; |N^"?bSt
}
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}catch(SQLException e){} alB'l
DBUtils.closeConnection(conn); :|$cG~'J
} OR*JWW[]
} vcsSi%M\U
public long getLast(){ &AOGg\
return lastExecuteTime; }6BXa
} AorY#oq
public void run(){ Z#B}#*<C
long now = System.currentTimeMillis(); -`DYDIr
if ((now - lastExecuteTime) > executeSep) { I`*5z;Q!%@
//System.out.print("lastExecuteTime:"+lastExecuteTime); tjwnFqI
//System.out.print(" now:"+now+"\n"); o&&`_"18
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); '`|j{mBhG
lastExecuteTime=now; iC5HrOl6U
executeUpdate(); @0s'
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} <ch}]-_
else{ ;Ce?f=4
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); c|JQ0] K
} BWQ`8
} }^0'IAXi
} u
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//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 6r`N\ :18
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类写好了,下面是在JSP中如下调用。 Z5n-3h!+ED
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<% !yPy@eP~
CountBean cb=new CountBean(); Y.) QNTh
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Gp
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CountCache.add(cb); W^h,O+vk
out.print(CountCache.list.size()+"<br>"); i+qg*o$
CountControl c=new CountControl(); %3~miP
c.run(); #O!2
out.print(CountCache.list.size()+"<br>"); #h^nvRmON
%>