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: =& q-[JW
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CountBean.java jD '
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/* <G~}N
* CountData.java r=~WMDCz@
* @K$VV^wp
* Created on 2007年1月1日, 下午4:44 M&qh]v gC
* Pt6hGSo.
* To change this template, choose Tools | Options and locate the template under 0%xR<<gir
* the Source Creation and Management node. Right-click the template and choose Uvjdx(fY[a
* Open. You can then make changes to the template in the Source Editor. L$+d.=]
*/ #`jE%ONC
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package com.tot.count; }+91s'/c
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/** =tr1*s{
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* @author `fBG~NDw
*/ OUEI~b1
public class CountBean { Sl3KpZ
private String countType; .i {>Z
int countId; @+'c+
/** Creates a new instance of CountData */ {&2$[g=[ ^
public CountBean() {} yZYKwKG
public void setCountType(String countTypes){ g.64Id
this.countType=countTypes; <y@,3DD3A9
} dB@Wn!Y
public void setCountId(int countIds){
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this.countId=countIds; GWF/[%
} r<;l{7lY_
public String getCountType(){ Lw*;tL<,
return countType; ic%?uWN
} ecr886
public int getCountId(){ A2m_q>>
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return countId; G9DJa_]X
} weNzYMf%
} U'tE^W
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CountCache.java H@V 7!d
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/* V,V*30K5
* CountCache.java bf& }8I$
* 1hl]W+9
* Created on 2007年1月1日, 下午5:01 ?2{bKIV_
* B?+.2
* To change this template, choose Tools | Options and locate the template under !X^Hi=aV
* the Source Creation and Management node. Right-click the template and choose UQ/qBbn
* Open. You can then make changes to the template in the Source Editor. M70c{s`w5
*/ P Q7A~dw9
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package com.tot.count; /QQ8.8=5
import java.util.*; l
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/** ).LTts7c
* ?a
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* @author wMGk!N
*/ CdY8#+"
public class CountCache { *n8%F9F
public static LinkedList list=new LinkedList(); c! @F
/** Creates a new instance of CountCache */ /D<"wF }@J
public CountCache() {} ["}A
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public static void add(CountBean cb){ |'tW=
if(cb!=null){ S='
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list.add(cb); "< v\M85&
} oK2pM18
} u_PuqRcs
} n-$VUo
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CountControl.java ;imRh'-V6
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/* '0:i<`qv#g
* CountThread.java [8"oj hdV
* QYQtMb,
* Created on 2007年1月1日, 下午4:57 A3HF,EG
* P-CB;\
* To change this template, choose Tools | Options and locate the template under ,_D"?o
* the Source Creation and Management node. Right-click the template and choose ZsZcQj6G,
* Open. You can then make changes to the template in the Source Editor. JWROYED
*/ XF}rd.K:
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package com.tot.count; - hzjV|
import tot.db.DBUtils;
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import java.sql.*; B<7/,d'
/** ][d,l\gu+s
* *#y;8
* @author `Gd$:qV
*/ H2;X
public class CountControl{ &.Q8Mi
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private static long lastExecuteTime=0;//上次更新时间 /RT%0!
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 aE|OTm+@9;
/** Creates a new instance of CountThread */ #`;/KNp 9
public CountControl() {} "CQw/qZw
public synchronized void executeUpdate(){ ~9=aT1S|
Connection conn=null; N
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PreparedStatement ps=null; C5W>W4EM
try{ Zj*\"Ol
conn = DBUtils.getConnection(); :!fG; )=
conn.setAutoCommit(false); AW,OHSXh6
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); \*0yaSQF
for(int i=0;i<CountCache.list.size();i++){ !:CJPM6j3
CountBean cb=(CountBean)CountCache.list.getFirst(); nmFC%p)4
CountCache.list.removeFirst(); pFsc}R/0/8
ps.setInt(1, cb.getCountId()); `zpbnxOL$T
ps.executeUpdate();⑴ O7t(,uox3y
//ps.addBatch();⑵ kforu!C
} GiFXX
//int [] counts = ps.executeBatch();⑶ R?66b{O
conn.commit(); ZJ,cQ+fn
}catch(Exception e){ AoaN22
e.printStackTrace(); 8K9$,Ii
} finally{ al&(-#1
try{ }_
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if(ps!=null) { _qXa=|}V.
ps.clearParameters(); Pw0Ci
ps.close(); ~8T(>!hE1h
ps=null; |=a}iU8
} !? 5U|
}catch(SQLException e){} KvPX=/&Zu
DBUtils.closeConnection(conn); }!>=|1fY
} ]aryV?!6
} [&?8,Q(
public long getLast(){ hsKmnH@#
return lastExecuteTime; .lgPFr6X
} Q&'}BeUbm
public void run(){ 6
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long now = System.currentTimeMillis(); A'&n5)tb
if ((now - lastExecuteTime) > executeSep) { '3IC*o"
//System.out.print("lastExecuteTime:"+lastExecuteTime); X^9d/}uTa
//System.out.print(" now:"+now+"\n"); >wHxmq8F5<
// System.out.print(" sep="+(now - lastExecuteTime)+"\n");
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lastExecuteTime=now; t*<#<a
executeUpdate(); G~7 i@Zs
} BvrB:%_:
else{ ] b9-k
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 6]zd.W
} >>i@r@
} YwY74w:
} wa=uUM_4u^
//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 ^ci3F<?Q=
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类写好了,下面是在JSP中如下调用。 ;Vik5)D2D
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<% |t
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CountBean cb=new CountBean(); W!!S!JF
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); jn >d*9u
CountCache.add(cb); Uo12gIX
out.print(CountCache.list.size()+"<br>"); #GDe08rOw
CountControl c=new CountControl(); @~c6qh
c.run(); rNjn~c
out.print(CountCache.list.size()+"<br>"); 1i:|3PA~
%>