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: %]!?{U\*k
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CountBean.java Kn.iyR
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/* >pnz_MQ
* CountData.java )Yrr%f`\
* tpE3|5dZF
* Created on 2007年1月1日, 下午4:44 "~Us#4>
* 1&} G+y
* To change this template, choose Tools | Options and locate the template under kHZKj!!R
* the Source Creation and Management node. Right-click the template and choose aC4m{F[
* Open. You can then make changes to the template in the Source Editor. 9'l.TcVm`,
*/ ]Px:d+wX:
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package com.tot.count; f}A^]6MO:
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/** N!Rt;Xm2@
* } cRi
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* @author /1U,+g^O>
*/ ddl3fl#f
public class CountBean { Q:rT 9&G
private String countType; S`fu+^cv
int countId; 4U:DJ_GN
/** Creates a new instance of CountData */ XPrY`,kN
public CountBean() {} *%;6P5n%
public void setCountType(String countTypes){ !P+~c0DF
this.countType=countTypes; ?NQD#
} Sv~PXi^`H
public void setCountId(int countIds){ bXk:~LE
this.countId=countIds; MI?]8+l
} dV'6m@C
public String getCountType(){ ,80jMs
return countType; uV/)Gb*j
} X*(gT1"t
public int getCountId(){ lrM.RM96
return countId; :+kg4v&r
} 7m vSo350
} # r2$ZCo3o
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CountCache.java }S1Z>ZA5
}//8$Z<(
/* `kI?Af*;v
* CountCache.java 17?NR\Q
* e-YGuWGN7
* Created on 2007年1月1日, 下午5:01 ";%e~
=
* qen44;\L
* To change this template, choose Tools | Options and locate the template under vY8WqG]
* the Source Creation and Management node. Right-click the template and choose +-xSuR,
* Open. You can then make changes to the template in the Source Editor. E,"b*l.
*/ {m1t~ S
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package com.tot.count; Off: ~
import java.util.*; &z{dr~
/** BVwRPt
* N?Z+zN&P
* @author 98"z0nI%
*/ f
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public class CountCache { q329z>
public static LinkedList list=new LinkedList(); i75?*ld
/** Creates a new instance of CountCache */ giA~+m~fN
public CountCache() {} 5,G<}cd
public static void add(CountBean cb){ Q}k_#w
if(cb!=null){ =l?"=HF
list.add(cb); W}<M?b4tP
} *R9mgv[
} [xp~@5r'
} &j
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CountControl.java `
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/* =_H*fhXS
* CountThread.java 8gu7f;H/k
* o+6^|RP
* Created on 2007年1月1日, 下午4:57 s K$Sar
* JVIcNK)
* To change this template, choose Tools | Options and locate the template under Hi4@!]
* the Source Creation and Management node. Right-click the template and choose d/-]y:`f`
* Open. You can then make changes to the template in the Source Editor. '8kL1
*/ 8zB+%mcF
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package com.tot.count; /i]=ndAk
import tot.db.DBUtils; {H7$uiq3:B
import java.sql.*; 7HR%rO?'
/** Kw5+4R(5
* "351s3ff
* @author $BO}D
*/ gWU(uBS
public class CountControl{ 3!L<=X
private static long lastExecuteTime=0;//上次更新时间 uvK%d\d
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Q/9vDv
/** Creates a new instance of CountThread */ &V,-W0T_
public CountControl() {} 6[Pr<4J
public synchronized void executeUpdate(){ #.t$A9'
Connection conn=null; @0@'6J04
PreparedStatement ps=null; f+W[]KK*PW
try{
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conn = DBUtils.getConnection(); Dm`U|<o
conn.setAutoCommit(false); bU +eJU_%
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); `5 v51TpH
for(int i=0;i<CountCache.list.size();i++){ h/y}
CountBean cb=(CountBean)CountCache.list.getFirst(); :R?| 2l
CountCache.list.removeFirst(); 4 >tYMyLt0
ps.setInt(1, cb.getCountId()); <?va)
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ps.executeUpdate();⑴ =rtA{g$)+
//ps.addBatch();⑵ D@vvy6>~s
} LyPBFo[?
//int [] counts = ps.executeBatch();⑶ 8LM1oal}
conn.commit(); Oj|p`Dzh
}catch(Exception e){ ,8 NEnB
e.printStackTrace(); IF?B`TmZ
} finally{ YGO 7lar
try{ 2B?i2[a,
if(ps!=null) { g4qdm{BL
ps.clearParameters(); Ol5xyj
ps.close(); %_=R&m'n`
ps=null; ZJ}LnPr
} -$|X\#R
}catch(SQLException e){} T-8nUo}i
DBUtils.closeConnection(conn); DczF0Ow
} |Ie`L("
} +&8Ud8Q
public long getLast(){ '9Odw@tp
return lastExecuteTime; !OVEA^6
} |(ju!&
public void run(){ g-gBg\y{v
long now = System.currentTimeMillis(); f0bV]<_9
if ((now - lastExecuteTime) > executeSep) { S&)
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//System.out.print("lastExecuteTime:"+lastExecuteTime); /%w[q:..h
//System.out.print(" now:"+now+"\n"); u`2k6.-
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); O;t?@!_
lastExecuteTime=now; ~*]`XL.-
executeUpdate(); a-2
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} .TS=[WGMS
else{ (uc)^lfX
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ,T[
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} u(`A?H:
} ;!sGfrs0$
} w o9f99
//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 Hxi=\2-
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类写好了,下面是在JSP中如下调用。 / {~h?P}
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<% eakIK+-21y
CountBean cb=new CountBean(); PdBhX
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); k(+u"T
CountCache.add(cb); WfO$q^'?DP
out.print(CountCache.list.size()+"<br>"); _oVA0@#n
CountControl c=new CountControl(); umn^QZ,
c.run(); gP%!
out.print(CountCache.list.size()+"<br>"); Y\\nJuJo
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