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:
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CountBean.java I4?oBq
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/* z]+L=+,,
* CountData.java S7Ty}?E@
* Ec3tfcNhR
* Created on 2007年1月1日, 下午4:44 ""a$[[ %WC
*
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* To change this template, choose Tools | Options and locate the template under H(K
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* the Source Creation and Management node. Right-click the template and choose [K\b"^=<
* Open. You can then make changes to the template in the Source Editor. 2wIJ;rh
*/ !e~[U-
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package com.tot.count; >20dK
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/** z<vh8dNl
* 4,c6VCw3+
* @author Z%B6J>;u M
*/ X(*O$B{
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public class CountBean { bNVeL$'
private String countType; w,FPL&{
int countId; &4S2fWx
/** Creates a new instance of CountData */ L}Y.xi
public CountBean() {} N\ !
public void setCountType(String countTypes){ /}m*|cG/
this.countType=countTypes; o!":mJy
} y7fy9jQ
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public void setCountId(int countIds){ SnmUh~`L~
this.countId=countIds; a~$Y;C_#<
} 3S7"P$q
public String getCountType(){ z77>W}d
return countType; }0Ns&6 )xG
} aYb97}kI
public int getCountId(){ DJ:'<"zH7
return countId; poxF`a6e+
} G_S>{<[
} G#7(6:=;,`
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CountCache.java 7
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/* R~k`KuY@!
* CountCache.java WXY'%G
* * /n8T]s
* Created on 2007年1月1日, 下午5:01 _<F)G,=
* 4A!]kj5T
* To change this template, choose Tools | Options and locate the template under jTcv&`fAz
* the Source Creation and Management node. Right-click the template and choose ZDW=>}~_y
* Open. You can then make changes to the template in the Source Editor. ;x/eb g
*/ ?l^Xauk4Pj
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package com.tot.count; kY~4AH
import java.util.*; CC`_e^~y=F
/** \toU zTT
* $3g{9)}
* @author 96(Mu% l
*/ 6^[4.D
public class CountCache { |2u=3#Jp
public static LinkedList list=new LinkedList(); ZhA_d#qH
/** Creates a new instance of CountCache */ sjg`4^!wDD
public CountCache() {} Q7$o&N{
public static void add(CountBean cb){ "a8E0b
if(cb!=null){ .PUp3X-
list.add(cb); zTw"5N
} _y^r==
} p/HDG
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} 2H)4}5H
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CountControl.java $ItjVc@U
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/* mOsp~|d
* CountThread.java MVsFi]-
* akzGJ3g
* Created on 2007年1月1日, 下午4:57 4\Y5RfLB_
* 0+* NHiH
* To change this template, choose Tools | Options and locate the template under pi?MAE*f
* the Source Creation and Management node. Right-click the template and choose +1!iwmch>
* Open. You can then make changes to the template in the Source Editor. Kf[d@L
*/ rR> X<
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package com.tot.count; o[Jzx2A<
import tot.db.DBUtils; Go)$LC0Mi
import java.sql.*; ){5Nod{}a
/** @owneSD qN
* }oRBQP^&K
* @author T$xBH
*/ 56 3mz-
public class CountControl{ tX{yR'Qhu
private static long lastExecuteTime=0;//上次更新时间 pa[/6(
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ~P1~:AT
/** Creates a new instance of CountThread */ P2-&Im`+
public CountControl() {} {_O!mI*
public synchronized void executeUpdate(){ _5jT}I<k
Connection conn=null; E^axLp>(I
PreparedStatement ps=null; 8Y?M:^f~
try{ >1Z"5F7=
conn = DBUtils.getConnection(); 'rcqy1-&
conn.setAutoCommit(false); v3I^81
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ,yYcjs!=o
for(int i=0;i<CountCache.list.size();i++){ 4N,mcV
CountBean cb=(CountBean)CountCache.list.getFirst(); y>P+"Z.K%}
CountCache.list.removeFirst(); $oK&k}Q
ps.setInt(1, cb.getCountId()); *|fF;-#v
ps.executeUpdate();⑴ +(3_V$|Dv
//ps.addBatch();⑵ ::|~tLFu
} g"! (@]L!@
//int [] counts = ps.executeBatch();⑶ "?I#!t%'
conn.commit(); /o;M
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}catch(Exception e){ t<!;shH,s
e.printStackTrace(); j~Aq-8R=
} finally{ ;.A}c)b
try{ 7Q}pKq]P
if(ps!=null) { M3pE$KT0x
ps.clearParameters(); u5(8k_7
ps.close(); <xOX+D
ps=null; -zR<m
} +WH\,E
}catch(SQLException e){} &]nx^C8V;
DBUtils.closeConnection(conn); %;,fI'M
} ci~#G[_$S
} ^`&'u_B!+
public long getLast(){ r7m~.M+W"
return lastExecuteTime; CJ IuMsZ
} zw/AZLS
public void run(){ zR" cj
long now = System.currentTimeMillis(); ZSC*{dD$E
if ((now - lastExecuteTime) > executeSep) { :!%V Sem
//System.out.print("lastExecuteTime:"+lastExecuteTime); HZyA\FS
//System.out.print(" now:"+now+"\n"); oN7SmP_
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Z}J5sifr
lastExecuteTime=now; oJ74Mra
executeUpdate(); $Habhw
} jx: IK
else{ q<JCgO-F<
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); $TI^8 3
} i+Z)`
} O$,Fga
} )U@9dV7u
//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 utlr|m Xc
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类写好了,下面是在JSP中如下调用。 [FO4x`
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<% 7n8nJTU{4j
CountBean cb=new CountBean(); ^3;B4tj[
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); -*C
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CountCache.add(cb); {M]_]L{&7
out.print(CountCache.list.size()+"<br>"); D}_.D=)
CountControl c=new CountControl(); 5R7x%3@L
c.run(); v@_1V
out.print(CountCache.list.size()+"<br>"); mci> MEb
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