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: UG9 Ha
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CountBean.java l7JY`x
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/* :-.bXOB(
* CountData.java uod&'g{N
* {#1}YGpiVM
* Created on 2007年1月1日, 下午4:44 m]U`7!
* ny~~xQ"
* To change this template, choose Tools | Options and locate the template under n.xW"omN
* the Source Creation and Management node. Right-click the template and choose ?g'? Ou
* Open. You can then make changes to the template in the Source Editor. *e05{C:kS
*/ "(d7:!%
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package com.tot.count; vvG#O[| O
*]
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/** 2V#(1Hc!
* p[%FH?
* @author [&
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*/ P\CT|K'P
public class CountBean { RoWGQney
private String countType; i/UHDqZ
int countId; i~6qOlLD-
/** Creates a new instance of CountData */ oos7x6
public CountBean() {} DrB PC@^
public void setCountType(String countTypes){ FCEFg)c5=
this.countType=countTypes; paW7.~3
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} +O@0gl
public void setCountId(int countIds){ oUBn:Ir@
this.countId=countIds; $/Q*@4t
} <J QvuC
public String getCountType(){
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return countType; "V;M,/Q|
} TM|ycS'
public int getCountId(){ u>.qhtm[
return countId; q G%'Lt
} G u-#wv5@
} R"=pAO.4l
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CountCache.java >{^&;$G+*
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/* V1j5jjck
* CountCache.java qJN2\e2~f
* <x),HTJ
* Created on 2007年1月1日, 下午5:01 z\8Kz ]n~
* F\Gi;6a
* To change this template, choose Tools | Options and locate the template under #yk
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* the Source Creation and Management node. Right-click the template and choose ]QS?fs Z
* Open. You can then make changes to the template in the Source Editor. tQ:)j^\
*/ Ln})\
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package com.tot.count; @4D$Xl
import java.util.*; !(soMv
/** ["\Y-6"l
* iii2nmiK
* @author !;^sIoRPV
*/ nDSmr
public class CountCache { (JHL0Z/
public static LinkedList list=new LinkedList(); 0BM3:]=wr
/** Creates a new instance of CountCache */ )q\|f_
public CountCache() {} TC4W7}}
public static void add(CountBean cb){ Ii/#cdgF
if(cb!=null){ g,!6,v@
list.add(cb); wYJ. F
} #s)Wzv%OX
} Wej 8YF@
} T,,,+gPx
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CountControl.java x-km)2x=W
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/* kckWBL
* CountThread.java '@h5j6:2
* YAqv:
* Created on 2007年1月1日, 下午4:57 gh3XC.&
* 3EN?{T<yf
* To change this template, choose Tools | Options and locate the template under ^|?/
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* the Source Creation and Management node. Right-click the template and choose Q&;dXE h
* Open. You can then make changes to the template in the Source Editor. POQRq%w
*/ wvum7K{tI
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package com.tot.count; X/fk&Cp
import tot.db.DBUtils; F`;oe[wfk
import java.sql.*; t/\J
/** ++Qg5FukR
* Cyg\FHs
* @author @54D<Lj
*/ MMglo3
public class CountControl{ jiMI&cl
private static long lastExecuteTime=0;//上次更新时间 &
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 'Jww}^h1
/** Creates a new instance of CountThread */ VQO6!ToKY
public CountControl() {} *wcb 5p
public synchronized void executeUpdate(){ o[W7'1O
Connection conn=null; vd>X4e^j
PreparedStatement ps=null; ]?p&sI4
try{ _6"!y
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conn = DBUtils.getConnection(); 0!YB.=\{_q
conn.setAutoCommit(false); _4VF>#b
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); G/Nb@pAy[
for(int i=0;i<CountCache.list.size();i++){ pmR6(/B#
CountBean cb=(CountBean)CountCache.list.getFirst(); rYbb&z!u
CountCache.list.removeFirst(); L\--h`~YU
ps.setInt(1, cb.getCountId()); &{?*aK&%3l
ps.executeUpdate();⑴ Cvr?%+)$M
//ps.addBatch();⑵ q$Z.5EN
} ,lLkAd?q
//int [] counts = ps.executeBatch();⑶ V8w!yc
conn.commit(); 3zU!5tg
}catch(Exception e){ BD+V{x}P
e.printStackTrace(); KPIc?|o/6
} finally{ z{w!yMp"
try{ 7KOM,FWKe
if(ps!=null) { p9ligs7V'
ps.clearParameters(); ?'_E$
ps.close(); =^m,|j|d>4
ps=null; &)@|WLW
} !%<bLD8
}catch(SQLException e){} 8jW"8~Y#0
DBUtils.closeConnection(conn); \*Roa&<!
} l(Dkmt>^
} V)CS,w
public long getLast(){ %y{#fZHc
return lastExecuteTime; =Jd('r
} 3A'vq2beM
public void run(){ FMCX->}$
long now = System.currentTimeMillis(); Gj[`r
if ((now - lastExecuteTime) > executeSep) { vs-%J6}G
//System.out.print("lastExecuteTime:"+lastExecuteTime); =l?F_
//System.out.print(" now:"+now+"\n"); N6Mo|
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ]5X=u(}
lastExecuteTime=now; #;59THdtPk
executeUpdate(); <QoSq'g#,=
} #gzY _)E
else{ [;3` Aw
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); jdsN ZV
} AV\6K;~
} ^sR]w]cz.
} Nf(Np1?;c
//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 !iBe/yb
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类写好了,下面是在JSP中如下调用。 #?/&H;n_8S
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<% BFP (2j
CountBean cb=new CountBean(); f$vWi&(
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); a[;TUc^I1F
CountCache.add(cb); MYgh^%w:
out.print(CountCache.list.size()+"<br>"); 5 Z+2
CountControl c=new CountControl(); $Fx:w
c.run(); :r%Hsur(
out.print(CountCache.list.size()+"<br>"); <smi<syx
%>