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: $@U`zy"Y
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CountBean.java 6-JnT_
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/* K crF=cA
* CountData.java SKS[Lf
* %\^x3wP&o\
* Created on 2007年1月1日, 下午4:44
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* V]<dh|x
* To change this template, choose Tools | Options and locate the template under ~bwFQYY=
* the Source Creation and Management node. Right-click the template and choose J
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* Open. You can then make changes to the template in the Source Editor. .O,gl$y}
*/ W35nnBU
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package com.tot.count; =]^*-f}J9
; w+A38N$J
/** Uvuvr_IP
* HN3
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* @author /R,/hiKx\
*/ BHU[Rz7x
public class CountBean {
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private String countType; XRz.R/
int countId; \
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/** Creates a new instance of CountData */ \twlHj4
public CountBean() {} JhD8.@} b~
public void setCountType(String countTypes){ %]
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this.countType=countTypes; bVVa5? HP
} WL7:22nSHa
public void setCountId(int countIds){ JLeV@NO
this.countId=countIds; 0? l
} !#X^nlc
public String getCountType(){ `=\G>#p<T
return countType; ~{N|("nB
} "W1 q}4_
public int getCountId(){ 0J_ x*k6
return countId; {6KU.'#iF
} O a7W&wi
} xWlB!r<}Gz
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CountCache.java <n#JOjHV
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/* wF&\@H
* CountCache.java >DV0!'jW
* .*,Zh2eXU
* Created on 2007年1月1日, 下午5:01 @Xh4ZMyEx
* hQkmB|];5
* To change this template, choose Tools | Options and locate the template under *JDc1$H0
* the Source Creation and Management node. Right-click the template and choose CsE|pXVG
* Open. You can then make changes to the template in the Source Editor. J=Jw"? f
*/ CZ0 {*K:
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package com.tot.count; =N3~2=g~A
import java.util.*; A#p@`|H#B
/** Dg]i};
* +wio:==
* @author ?r@ZTuq#
*/ f.u{;W
public class CountCache { fW\u*dMMZE
public static LinkedList list=new LinkedList(); p3Gj=G
/** Creates a new instance of CountCache */ RJ-CWt
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public CountCache() {} [0rG"$(0Y
public static void add(CountBean cb){ #VrT)po+
if(cb!=null){ >U}~Hv]
list.add(cb); =6 [!'K
} 3C[ ;2
} X `vDhfh>N
} |W::\yu6
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CountControl.java BujWql
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/* .Kv@p jOr
* CountThread.java h&Sl8$jVp
* &v`kyc
* Created on 2007年1月1日, 下午4:57 kP| !!N
* oW8[2$_N+
* To change this template, choose Tools | Options and locate the template under \k* ]w_m-
* the Source Creation and Management node. Right-click the template and choose 2ru6bIb;
* Open. You can then make changes to the template in the Source Editor. nd?m+C&W
*/ oL~Yrb%R
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package com.tot.count; "y`?KY$[N
import tot.db.DBUtils; <6`,)(dj
import java.sql.*; SY{J
/** 4C2 Dwj
* *r_.o;6
* @author dxd}:L~z
*/ 5-g0 2g
public class CountControl{ Lf,gS*Tg?
private static long lastExecuteTime=0;//上次更新时间 UC0 yrV
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 M\]E;C'"U
/** Creates a new instance of CountThread */ m760K*:i\
public CountControl() {} 5|/vc*m_0'
public synchronized void executeUpdate(){ 9#agI|d~
Connection conn=null; (Hsfrc
PreparedStatement ps=null; Z86[sQBg
try{ RXP"v-
conn = DBUtils.getConnection(); S !e0:
conn.setAutoCommit(false);
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ="4jk=on
for(int i=0;i<CountCache.list.size();i++){ z4<h)hh"k6
CountBean cb=(CountBean)CountCache.list.getFirst(); kfHLjr.
CountCache.list.removeFirst(); (O&b:D/Y
ps.setInt(1, cb.getCountId()); $51#xe
ps.executeUpdate();⑴ ~:0h o
//ps.addBatch();⑵ k4|YaGhf
} oDRNM^gz
//int [] counts = ps.executeBatch();⑶ fpqKa r
conn.commit(); $L&*0$[]Q
}catch(Exception e){ M\GS&K$lq
e.printStackTrace(); i7p3GBXh[
} finally{ UOwj"#
try{ )oNomsn
if(ps!=null) { =l\D7s
ps.clearParameters(); .d*v fE$
ps.close(); <;Xj4
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ps=null; W[vak F
} )h/fr|
}catch(SQLException e){}
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DBUtils.closeConnection(conn); CR_A{(
} fu|I(^NV
} ,JjTzO
public long getLast(){ ClEtw
return lastExecuteTime; T|=8jt,
} 0 8U:{LL
public void run(){ \;sUJr"$
long now = System.currentTimeMillis(); p'R}z|d)
if ((now - lastExecuteTime) > executeSep) { +[>m`XTq
//System.out.print("lastExecuteTime:"+lastExecuteTime); %@IR7v~
//System.out.print(" now:"+now+"\n"); ?2i``-|Wa
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Z$@Juv&>5^
lastExecuteTime=now; ?>w%Lg{L}
executeUpdate(); ,,6e }o6
} )cvC9gt
else{ VMNihx0FJ
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); L-Hl.UV
} {:? -)Xq
} S4\T (
} [3\}Ca1
//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 #]C r
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类写好了,下面是在JSP中如下调用。 5ecqJ
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<% 8L<Ol
CountBean cb=new CountBean(); * %MY. #
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); EJRwyF5LK
CountCache.add(cb); Xf.SJ8G
out.print(CountCache.list.size()+"<br>"); z7GLpTa
CountControl c=new CountControl(); u6D>^qF}@'
c.run(); 2AdV=n6Z
out.print(CountCache.list.size()+"<br>");
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%>