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: _CL{IY
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CountBean.java i\ "{#
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/* WI{ ;#A
* CountData.java :xtT)w
* f]]f85
* Created on 2007年1月1日, 下午4:44 M|H2kvl
* pr/'J!{^
* To change this template, choose Tools | Options and locate the template under K'V 2FTJI
* the Source Creation and Management node. Right-click the template and choose cl_TF[n?
* Open. You can then make changes to the template in the Source Editor. 7VY8CcL
*/ x%pRDytA
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package com.tot.count; NN mM#eB:4
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/** 6uqUiRs()
* 9$wAm89
* @author ##GY<\",;
*/ {m'AY)
public class CountBean { p(?g-
private String countType; vzG ABP
int countId; e,"FnW
/** Creates a new instance of CountData */ 8gAu7\p}
public CountBean() {} )P%4:P
public void setCountType(String countTypes){ E<k^S{
this.countType=countTypes; fdLBhe#9M
} ?M~
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public void setCountId(int countIds){ S eOy7
this.countId=countIds; D7gHE
} ,\x$q'
public String getCountType(){ tpZ->)1
return countType; Wj tft%
} OT@yPG
public int getCountId(){ _@K YF)
return countId; kIX)oD}c
} 86qcf"?E
} 6bUl>4
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CountCache.java j76%UG\Ga
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/* }/"4|U
* CountCache.java %/!+(7
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* YXRjx.srf
* Created on 2007年1月1日, 下午5:01 WL:0R>0
* c 6q/X*
* To change this template, choose Tools | Options and locate the template under #Wk5E2t
* the Source Creation and Management node. Right-click the template and choose z37Z%^
* Open. You can then make changes to the template in the Source Editor. -;/
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*/ =Epq%,4nG
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package com.tot.count; B:nK)"{
import java.util.*; M $uf:+F
/** A%n?}
* ST%
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* @author s??czM2O
*/ yV2e5/i
public class CountCache { [T]Bf o
public static LinkedList list=new LinkedList(); shzG
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/** Creates a new instance of CountCache */ - wWRm
public CountCache() {} ~bGC/I;W>
public static void add(CountBean cb){ %6HX*_Mr&
if(cb!=null){ ?;RD u[eD
list.add(cb); ,J&9kYz
} x`L+7,&n
} }LQ\a8]<
} $Elkhe]O %
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CountControl.java ckWkZ
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/* bRsc-Fz6
* CountThread.java ;W~4L+e
* }^9paU
* Created on 2007年1月1日, 下午4:57 I&\4C.\>
* AK;^9b-}q:
* To change this template, choose Tools | Options and locate the template under AAo0M/U'
* the Source Creation and Management node. Right-click the template and choose &?r*p0MQC
* Open. You can then make changes to the template in the Source Editor. p&O8qAaO
*/ A Iv<f9*.:
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package com.tot.count; rKT)!o'
import tot.db.DBUtils; ?Q?598MC
import java.sql.*;
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/** N%*9&FjrL
* r&Qt_
* @author b!,ja?
*/ K"^cq~
public class CountControl{ ;j!UY.i
private static long lastExecuteTime=0;//上次更新时间 ^vW$XRnt
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 5{>>,pP&
/** Creates a new instance of CountThread */ fp tIc#4
public CountControl() {} 1!1DuQ
public synchronized void executeUpdate(){ wHWma)}-z
Connection conn=null; tUv3jq)n%
PreparedStatement ps=null; F9O`HFVK
try{ 4|=vxJ
conn = DBUtils.getConnection(); wE4;Rk1
conn.setAutoCommit(false); vcM~i^24)
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); %l;*I?0H
for(int i=0;i<CountCache.list.size();i++){ 8,y{q9O
CountBean cb=(CountBean)CountCache.list.getFirst(); <r3Jf}%tT
CountCache.list.removeFirst(); W #47Cz
ps.setInt(1, cb.getCountId()); y+RRg[6|
ps.executeUpdate();⑴ PT05DH
//ps.addBatch();⑵ ftaBilkjp
} :G0+;[?N
//int [] counts = ps.executeBatch();⑶ 4i`S+`#
conn.commit(); >j:|3atb
}catch(Exception e){ F^miq^K=
e.printStackTrace(); DyIV/
} finally{ -!~vA+jw1
try{ OW#_ty_ul
if(ps!=null) { %",ULtZ+
ps.clearParameters(); ]zcV]Qj$~
ps.close(); C#h76fpH
ps=null; lz}llLb1
} Pa[?L:E
}catch(SQLException e){} p+)C$2YK
DBUtils.closeConnection(conn); #@E(<Pu4`
} sS|<&3
} >Fp&8p`am
public long getLast(){ SM$\;)L
return lastExecuteTime; G:DSWW}
} bOe<\Y$
public void run(){ :Fnzi0b
long now = System.currentTimeMillis(); BvQUn@ XE
if ((now - lastExecuteTime) > executeSep) { *w|iu^G
//System.out.print("lastExecuteTime:"+lastExecuteTime); P8IRH#ED
//System.out.print(" now:"+now+"\n"); 5Xj|:qz<(
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); #w;;D7{@m
lastExecuteTime=now; Vf$1Sj w
executeUpdate(); oc:x&`j
} 'QR4~`6I
else{ ET3,9+Gj
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); =EWD
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} /cYk+c
} NN11}E6
} GZS{&w!
//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 RyE_|]I62u
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类写好了,下面是在JSP中如下调用。 ]` K[W &
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<% WSS(Bm|B
CountBean cb=new CountBean(); ExQ--!AC=
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); w~]}acP
CountCache.add(cb); F=:c5z
out.print(CountCache.list.size()+"<br>"); aX]y`
CountControl c=new CountControl(); Lg b
c.run(); TG?fUD V
out.print(CountCache.list.size()+"<br>"); =/m}rcDN
%>