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: J-F".6i5
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CountBean.java
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/* #%0V`BS7n
* CountData.java ~C.*Vc?|
* l4Xz r:]
* Created on 2007年1月1日, 下午4:44 rl*O-S/
* Ifj&S'():
* To change this template, choose Tools | Options and locate the template under O !L`0
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* the Source Creation and Management node. Right-click the template and choose VM"cpC_8
* Open. You can then make changes to the template in the Source Editor. *Z5^WHwg
*/ 'X`Z1L/
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package com.tot.count; &SY!qTxF
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/** _FLEz|%~
* vJkc/7
* @author [4Z 31v>
*/ XpQ Ol
public class CountBean { S&op|Z)1
private String countType; Ykbg5Z
int countId; u2V-V#jS
/** Creates a new instance of CountData */ }I"C4'(a
public CountBean() {} I5$P9UE+^9
public void setCountType(String countTypes){ S2~cAhR|M
this.countType=countTypes; f&
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}
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public void setCountId(int countIds){ Kz4S6N c
this.countId=countIds; L+%"ew
} )
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public String getCountType(){ N+-Tp&:wY
return countType; XZ
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} 1SQATUV
public int getCountId(){ gt&|T
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return countId; ~}/Dl#9R!
} l^B.iB
} E_HB[9
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CountCache.java cPGlT"
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/* "cH RGJG#
* CountCache.java <P9fNBGa
* Y4T")
* Created on 2007年1月1日, 下午5:01 B{-7
* D7ex{SVA)
* To change this template, choose Tools | Options and locate the template under $6QIYF""
* the Source Creation and Management node. Right-click the template and choose R#(0C(FI^
* Open. You can then make changes to the template in the Source Editor. F /b`[
*/ X>%nzY]m
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package com.tot.count; 7\u+%i;YZ
import java.util.*; zd?@xno
/** J(
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* *OVB;]D3+
* @author 6 Z/`p~e
*/ +)Te)^&v%
public class CountCache { Z5{a7U4z_
public static LinkedList list=new LinkedList(); :NzJvI<
/** Creates a new instance of CountCache */ Ycm)PU ["
public CountCache() {} R+sT
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public static void add(CountBean cb){ FB=oGgwwq
if(cb!=null){ R{hX--|j
list.add(cb); bIKg>U'5d
} od;-D~
} JuRoeq.
} 'Pz%c}hJ
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CountControl.java JFq
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/* d{
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* CountThread.java yTaMlT|
* k<1yv$/mW
* Created on 2007年1月1日, 下午4:57 QWmE:F[M~
* O9gq <d
* To change this template, choose Tools | Options and locate the template under ;rh.6D l
* the Source Creation and Management node. Right-click the template and choose Ku;fZN[g
* Open. You can then make changes to the template in the Source Editor. ^-;S&=
*/ E(qYCafC
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package com.tot.count; +,Dc0VC?
import tot.db.DBUtils; G#iQX`
import java.sql.*; q:{#kv8
/** )!y>2$20 r
* ;%|im?
* @author [ X*p
[
*/ eK8H5YE
public class CountControl{ e~h>b.~
private static long lastExecuteTime=0;//上次更新时间 )W@ug,y
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 6|97;@94
/** Creates a new instance of CountThread */ pMF
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public CountControl() {} #mH@ /6,#[
public synchronized void executeUpdate(){ :,BAw ,
Connection conn=null; 5Iu5N0cn
PreparedStatement ps=null; B6XO&I1c
try{ tMr7d
conn = DBUtils.getConnection(); k(Yz2
conn.setAutoCommit(false); |5@Ra@0
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); OhF55,[
for(int i=0;i<CountCache.list.size();i++){ :\](m64z;
CountBean cb=(CountBean)CountCache.list.getFirst(); ` Xc7b
CountCache.list.removeFirst(); gv!8' DKn
ps.setInt(1, cb.getCountId()); !}*N';
ps.executeUpdate();⑴ <H[w0Z$
//ps.addBatch();⑵ \u=d`}E
} `At.$3B
//int [] counts = ps.executeBatch();⑶ 0'q4=!l
conn.commit(); $CcjuPsK
}catch(Exception e){ %wD#[<BGn>
e.printStackTrace(); *MJm:
} finally{ v|?@k^Ms
try{ j:9M${~
if(ps!=null) { HKN|pO3v
ps.clearParameters(); %V_ XY+o
ps.close(); jKS j );
ps=null; , c.^"5
} _h%Jf{nu
}catch(SQLException e){}
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DBUtils.closeConnection(conn); +/OSg.
} whI{?NP
} (qcFGM22U
public long getLast(){ $C16}^
return lastExecuteTime; OT#@\/>
} m l`xLZN>L
public void run(){ E4#{&sRT
long now = System.currentTimeMillis(); \0@DOW22C
if ((now - lastExecuteTime) > executeSep) { OM'iJB6=
//System.out.print("lastExecuteTime:"+lastExecuteTime); 8jK=A2pTa
//System.out.print(" now:"+now+"\n"); glAS$<
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); eSPS3|YYn
lastExecuteTime=now; e8,_"_1:F
executeUpdate(); t]c<HDCK
} YOxgpQ:i
else{ cS&KD@.
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); O7.V>7Y9H
} ,@"yr>Q9#6
} *i#2>=)
} Zy0M\-Mn
//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 So5/n7
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类写好了,下面是在JSP中如下调用。 O{ :{P5
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<% I=`? 4%
CountBean cb=new CountBean(); &9jJ\+:7
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); -:}vf?
CountCache.add(cb); b,~'wm8:A
out.print(CountCache.list.size()+"<br>"); IRW0.'Dn
CountControl c=new CountControl(); b1xE;0uR
c.run(); gI:g/ R
out.print(CountCache.list.size()+"<br>"); !G%!zNA S
%>