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: azR<Y_tw
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CountBean.java m6tbN/EJZ
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/* a5ZU"6Hi
* CountData.java {2G9>'
* S453oG"
* Created on 2007年1月1日, 下午4:44 l?v`kAMR
* &cztUM(
* To change this template, choose Tools | Options and locate the template under ,}2yxo;i
* the Source Creation and Management node. Right-click the template and choose QEK,mc3
* Open. You can then make changes to the template in the Source Editor. &S}%)g%Iv9
*/ [T#5$J
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package com.tot.count; Qg;A (\z
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/** <
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* [` ~YPUR*
* @author LWE[]1=
*/ nlJ~Q_E(
public class CountBean { o:B?gDM
private String countType; )j(13faW|
int countId; B2t.;uz(,
/** Creates a new instance of CountData */ X{zg-k(@
public CountBean() {} (e sTb,
public void setCountType(String countTypes){ 9 X}F{!p~1
this.countType=countTypes; im{'PgiR
} ON#\W>MK?
public void setCountId(int countIds){ z1[2.&9D-
this.countId=countIds; j_S///
} rOQhS]TP*
public String getCountType(){ Bf!i(gM
return countType; v9R#=m/=
} Fq/?0B8
public int getCountId(){ wEL$QOu$
return countId; +^tq?PfE
} YY-{&+,
} `l,=iy$
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CountCache.java !]1X0wo\
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/* #R$d6N[H
* CountCache.java |d^r"wbs3
* +;~JHx.~X
* Created on 2007年1月1日, 下午5:01 _h>S7-X
* R r! PU
* To change this template, choose Tools | Options and locate the template under uU(G &:@
* the Source Creation and Management node. Right-click the template and choose 6OR5zXpk
* Open. You can then make changes to the template in the Source Editor. 6Ug(J$Ouh
*/ s\QhCS
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package com.tot.count; lxoc.KDtR
import java.util.*; cAq>|^f0a
/** 2GOQ| Z
* &09z`*,
* @author u4TU"r("A
*/ >!O3 jb k
public class CountCache { Nf8."EDUW
public static LinkedList list=new LinkedList(); YSwAu,$jf
/** Creates a new instance of CountCache */ !Cxo4Twg
public CountCache() {} 1~:7W
public static void add(CountBean cb){ xc dy/J&
if(cb!=null){ {[WEA^C~Q
list.add(cb); hZ|*=/3k
} q !\Ht2$b
} d%_v
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} ].53t"*
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CountControl.java S|!)_RL
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/* f`'? 2
* CountThread.java K=Z~$)Og)
* ULc oti=,
* Created on 2007年1月1日, 下午4:57 ^$qr6+
* z-fP#.
* To change this template, choose Tools | Options and locate the template under x*td
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* the Source Creation and Management node. Right-click the template and choose z`UL)W
* Open. You can then make changes to the template in the Source Editor. e3w4@V`
*/ PD$XLZ
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package com.tot.count; 2[f8"'lUQ
import tot.db.DBUtils; taOD,}c|$
import java.sql.*; yO Ed8
/** MGpP'G:v
* 0<*R 0
* @author O{Bll;C
*/ yf`Nh
public class CountControl{ Yqz(@( %
private static long lastExecuteTime=0;//上次更新时间 {<0=y#@u
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 i5wXT
/** Creates a new instance of CountThread */ qN((Xz+AZE
public CountControl() {} .),ql_sXr
public synchronized void executeUpdate(){ f)w>V3~w,
Connection conn=null; sv`+?hjG
PreparedStatement ps=null; ipU,.@~#
try{ SA_5..
conn = DBUtils.getConnection(); =au7'i |6
conn.setAutoCommit(false); QX}O{LQR
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); v0euvs
for(int i=0;i<CountCache.list.size();i++){ x'Pp!
CountBean cb=(CountBean)CountCache.list.getFirst(); OB"Ur-hJ0
CountCache.list.removeFirst(); xG sg'
ps.setInt(1, cb.getCountId()); r0kJx$f
ps.executeUpdate();⑴ U-/-aNJ]U
//ps.addBatch();⑵ @+II@[_lT
} iu!j#VO
//int [] counts = ps.executeBatch();⑶ _kUf[&
conn.commit(); @IL_
}catch(Exception e){ =d>^q7s
e.printStackTrace(); Zwj\Hz.
} finally{ #T<<{ RA
try{ S1oRMd)r
if(ps!=null) { vi?{H*H4c
ps.clearParameters(); ~lO^C
ps.close(); Z)E[Bv=
ps=null; 6 ,jp-`
} u,AZMjlF
}catch(SQLException e){} oE:9}]N_
DBUtils.closeConnection(conn); bOR1V\Jr$q
} N&g9z{m7
} VZ"W_U,
public long getLast(){ } :U'aa
return lastExecuteTime; nXH U|5.I
} Lc,`
public void run(){ f9v%k'T[
long now = System.currentTimeMillis(); dIk/vg
if ((now - lastExecuteTime) > executeSep) { sOzmw^7
//System.out.print("lastExecuteTime:"+lastExecuteTime); *m2{6N_
//System.out.print(" now:"+now+"\n"); 1 .\|,$
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 3S4'x4*
lastExecuteTime=now; 5J!ncLNm{
executeUpdate(); 3[8F:I0UL
} 9W{`$30
else{ LASR*
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); .)Xyzd
} Vk%[N>
} I|jGu9G
} g+>$_s
//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 b0W~*s [4
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类写好了,下面是在JSP中如下调用。 /)I:Cz/f
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<% S!!i
CountBean cb=new CountBean(); /H 3u^
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); |eS5~0<`
CountCache.add(cb); p H&Tb4
out.print(CountCache.list.size()+"<br>"); &t.9^;(
CountControl c=new CountControl(); AIZs^
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c.run(); ?VC[%sjwn
out.print(CountCache.list.size()+"<br>"); G#{
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%>