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: 1L.yh U\
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CountBean.java W.<I:q`eO
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/* [M:BJ%*
* CountData.java D^2yP~(
* +|Qe/8Q
* Created on 2007年1月1日, 下午4:44 G6j9,#2@
* $!"*h
* To change this template, choose Tools | Options and locate the template under v:Z.8m8D
* the Source Creation and Management node. Right-click the template and choose ^ `Y1
* Open. You can then make changes to the template in the Source Editor. 9 Dx9alJR
*/ }!Xj{Eoc
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package com.tot.count; -cWxS{vO
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/** E9S&UU,K
* L3X[; |v}
* @author h+Tt+Q\
*/ Z+x`q#ZQr
public class CountBean { .Ue1}'v*,
private String countType; J+8T Ie
int countId; Y&`nB,'
/** Creates a new instance of CountData */ qXQ7Jg9
public CountBean() {} zI3Bb?4.
public void setCountType(String countTypes){ X6:
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this.countType=countTypes; jiAN8t*P
} 3+ r8yiY
public void setCountId(int countIds){ Uzd\#edxJ
this.countId=countIds; MQGR-WV=5
} v"smmQZik
public String getCountType(){ #k<j`0kiq
return countType; ,(CIcDJ2U_
}
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public int getCountId(){ T=->~@5
return countId; C9FQo7
} $v+t~b
} 9!oNyqQ
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CountCache.java 38eeRo
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/* '#0'_9}
* CountCache.java p/inATH
* @I|gA
* Created on 2007年1月1日, 下午5:01 bT{iei]?
* F]~>qt<ia
* To change this template, choose Tools | Options and locate the template under Wi(Ac8uh
* the Source Creation and Management node. Right-click the template and choose y2,M9
* Open. You can then make changes to the template in the Source Editor. {QTnVS't 0
*/ 4&([<gyR<
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package com.tot.count; eo&nAr
import java.util.*; 5m&Zq_Qe
/** S&YC"
* R7d45Wl
* @author ]\5?E }kd
*/ B @8
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public class CountCache { \`M8Mu9~w
public static LinkedList list=new LinkedList(); _}-Ed,.=
/** Creates a new instance of CountCache */ uDpCW}
public CountCache() {} :vk TV~
public static void add(CountBean cb){ b$:<T7vei
if(cb!=null){ Cl5l+I\1
list.add(cb); &I$MV5)u
} ("B[P/
} 3ud_d>
} Wc+)EX~KS
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CountControl.java kKqb:
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/* F"<TV&xf
* CountThread.java &{c.JDO
* hf~'EdU
* Created on 2007年1月1日, 下午4:57 .v{ok,&
* o1kY|cnGH
* To change this template, choose Tools | Options and locate the template under mew,S)dq!
* the Source Creation and Management node. Right-click the template and choose 9c@."O`
* Open. You can then make changes to the template in the Source Editor. +bw>9VmG
*/ AsW!GdIN
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package com.tot.count; $Dm2>:Dmt
import tot.db.DBUtils; j!:^+F/
import java.sql.*; &6`h%;a/&
/** lef,-{X-
* R6A{u(
* @author `i,l)X]
*/ %cl=n!T
public class CountControl{ wjm _bEi
private static long lastExecuteTime=0;//上次更新时间 AD=vYDR+
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 S_VZ^1X]
/** Creates a new instance of CountThread */ u2G{I?
public CountControl() {} :mwJJIjUW
public synchronized void executeUpdate(){ eI7FbOze
Connection conn=null; i0y^b5@MOb
PreparedStatement ps=null; uwcm%N;I"
try{ Gb\Nqx(
conn = DBUtils.getConnection(); 8AK=FX&@&
conn.setAutoCommit(false); ^T#bla893
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); #ONad0T;
for(int i=0;i<CountCache.list.size();i++){ .W#-Cl&n8
CountBean cb=(CountBean)CountCache.list.getFirst(); %&RF;qa2xu
CountCache.list.removeFirst(); <B?@,S>
ps.setInt(1, cb.getCountId()); -<[MM2Y
ps.executeUpdate();⑴ j<-#a^jb
//ps.addBatch();⑵ mu[:b
} Qt@_C*,P
//int [] counts = ps.executeBatch();⑶ +y$%S4>0tp
conn.commit(); ;p!|E3o.
}catch(Exception e){ 0'IV"eH2
e.printStackTrace(); SCCBTpmf2B
} finally{ a9ko3L
try{ ")t
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if(ps!=null) { bV5 {
ps.clearParameters(); Cz%tk}2
ps.close(); I0
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ps=null; H<|ilL'fX
} .S l{m[nV8
}catch(SQLException e){} `5V=U9zdE
DBUtils.closeConnection(conn); Z-fQ{&a{
} c&{1Z&Y
} .K=r.tf~
public long getLast(){ f.%mp$~T
return lastExecuteTime; .>Gnb2
} UbD1h_b
public void run(){ gkJL=,
long now = System.currentTimeMillis(); GESEj%R/b
if ((now - lastExecuteTime) > executeSep) { F~`Yh6v
//System.out.print("lastExecuteTime:"+lastExecuteTime); p5C:MA~*
//System.out.print(" now:"+now+"\n"); \DG
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 6QwVgEnSf
lastExecuteTime=now; =ZE]jmD4P
executeUpdate(); Df\~ ZWs!
} v-k~Q$7~
else{ PgeC\#;9
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); #mI{D\UR
} 5/vfmDt3'G
} INi9`M.h
} CWP),]#n
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 PJq;OM|
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类写好了,下面是在JSP中如下调用。 A{[joo
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<% |\?mX=a.y
CountBean cb=new CountBean(); iYqZBLf{S
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); kYlsjM
CountCache.add(cb); 0pO{ {F
out.print(CountCache.list.size()+"<br>"); T<hS
CountControl c=new CountControl(); s$cr|p;7#
c.run(); 'MM%Sm,
out.print(CountCache.list.size()+"<br>"); 81gcM?
%>