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: K; +w'/{
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CountBean.java {iI"Lt
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/* VqeK~,}
* CountData.java J^J$I!
* i'$V'x'k
* Created on 2007年1月1日, 下午4:44 <&+\X6w[
* )r)3.|wJm
* To change this template, choose Tools | Options and locate the template under H40~i=.
* the Source Creation and Management node. Right-click the template and choose 7( &\)qf=n
* Open. You can then make changes to the template in the Source Editor. !`rR;5&sT
*/ ^rmcyy8;g
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package com.tot.count; :q.g#:1s
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/** i7D)'4gkW
* NT^m.o~4
* @author LB1AjNJ
*/ YQ&Ww|xe
public class CountBean { 5p. vo"7
private String countType; KZ"&c~[
int countId; <QUjhWxDb
/** Creates a new instance of CountData */ +ti_?gfx
public CountBean() {} }W:Rg}v
public void setCountType(String countTypes){ H+oQ
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this.countType=countTypes; t4RI%m\
} 1gA9h-'w
public void setCountId(int countIds){ {!lC$ SlJ
this.countId=countIds; :/c40:[
} ZB)`*z>*
public String getCountType(){ k_E
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return countType; <}@*i
} T=EHue$
public int getCountId(){ `Dck$
return countId; fL #e4
} |#_ F
} 'UYxVh9D
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CountCache.java ^ucmScl
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/* 'S_OOzpC
* CountCache.java \i*QKV<
* H+ P&}
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* Created on 2007年1月1日, 下午5:01 x:7"/H|
* Y+,ii$Ce~
* To change this template, choose Tools | Options and locate the template under cN#c25S>
* the Source Creation and Management node. Right-click the template and choose 59Lv/Mfy
* Open. You can then make changes to the template in the Source Editor. Dsl,(qm5
*/ 0^H"eQO
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package com.tot.count; MY8[)<q"
import java.util.*; <6
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/** KI@OEy
* 4jOq.j
* @author 5Iql%~_x
*/ K}vP0O}
public class CountCache { DLigpid
public static LinkedList list=new LinkedList(); "Je*70LG#
/** Creates a new instance of CountCache */ fEdp^oVg
public CountCache() {} eSqKXmH[m
public static void add(CountBean cb){ Bb,l.w
if(cb!=null){ 3Kx&+
list.add(cb); =bx;TV
} TpB4VNi/<
} #2/2Xv
} zS9HR1
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CountControl.java !mjrI "_
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/* ^\ N@qL
* CountThread.java #~_ZG% u
* | 61W-9;
* Created on 2007年1月1日, 下午4:57
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* AYVkJq ?
* To change this template, choose Tools | Options and locate the template under I"=a:q
* the Source Creation and Management node. Right-click the template and choose c#ahFpsnlw
* Open. You can then make changes to the template in the Source Editor. 6njwrqo
*/ %nRz~3X|+v
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package com.tot.count; c'wxCqnE
import tot.db.DBUtils; Y<]A5cm
import java.sql.*; w$aiVOjgT
/** X6T*?t3!9[
* \>DMN #
* @author dR9[K4`p/
*/ d)R7#HLZ7
public class CountControl{ \CY_nn|&g
private static long lastExecuteTime=0;//上次更新时间 ujLz<5gKuO
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 7f$ hg8
/** Creates a new instance of CountThread */ 8wi2&j_
public CountControl() {} G~VukW<e
public synchronized void executeUpdate(){ \l_U+d,qq
Connection conn=null; j(QK 0 "z
PreparedStatement ps=null; fn~Jc~[G|
try{ m,Fug1+N
conn = DBUtils.getConnection(); F['<;}
conn.setAutoCommit(false); 8l50@c4UF~
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); `y^tCJ2u*
for(int i=0;i<CountCache.list.size();i++){ .|VWYN
CountBean cb=(CountBean)CountCache.list.getFirst(); Knjg`f
CountCache.list.removeFirst(); u ?
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ps.setInt(1, cb.getCountId()); hhM?I$t:
ps.executeUpdate();⑴ /c&;WlE/n
//ps.addBatch();⑵ r(VGdG
} Ft[)m#Dj`
//int [] counts = ps.executeBatch();⑶ sTb@nrRxH
conn.commit(); 38gHM9T
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}catch(Exception e){ * NB:"1x
e.printStackTrace(); G-DvM6T
} finally{ !W4X4@
try{ dsUt[z1w5
if(ps!=null) { k"L?("~
ps.clearParameters(); ,ix> e
ps.close(); .H33C@
ps=null; -~|E(ys
} )LdS1%
}catch(SQLException e){} o6v'`p'
DBUtils.closeConnection(conn); i?+>,r@\p
} A*a:#'"*N
} >!gW]{
public long getLast(){ K:JM*4W
return lastExecuteTime; b~u53
} vJ a?5Jr
public void run(){ j1sgvh]D
long now = System.currentTimeMillis(); U9/>}Ni%3G
if ((now - lastExecuteTime) > executeSep) { H wu(}
//System.out.print("lastExecuteTime:"+lastExecuteTime); 79bt%P
//System.out.print(" now:"+now+"\n"); !8Mi+ZV
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 8%,u~ELA
lastExecuteTime=now; w(EUe4 w{
executeUpdate(); Wu1">|
} Lc?q0x^s
else{ kWKAtv5@w
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); K]Rb~+a<
} rQ:+LVfXjA
} Z{ AF8r
} "Xz [|Xl
//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 b-"kclK
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类写好了,下面是在JSP中如下调用。 EqjaD/6Y`
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<% H7}@56
CountBean cb=new CountBean(); VmbfwHRWb
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); b;~?a#Z}
CountCache.add(cb); m +LP5S
out.print(CountCache.list.size()+"<br>"); +ak<yV1=
CountControl c=new CountControl(); "/~KB~bB
c.run(); r/e} DYL&
out.print(CountCache.list.size()+"<br>"); )C^@U&h&
%>