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: aW:*!d#
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CountBean.java e;=R8i
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/* *H/)S 5
* CountData.java _K?v^oM#
* -ioO8D&!
* Created on 2007年1月1日, 下午4:44 JUw|nUnl?
* 0*]0#2Z
* To change this template, choose Tools | Options and locate the template under r^.9
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* the Source Creation and Management node. Right-click the template and choose o]p$
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* Open. You can then make changes to the template in the Source Editor. o!h::j0,~
*/ w$$pTk|&n
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package com.tot.count; I[Bp}6G
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/** }6LcimQyK
* ZWyf.VJ
* @author ,hNs{-*
*/ RoHX0
public class CountBean { c)Q-yPMl)
private String countType; kxe{HxM$Z
int countId; =^M Q 4
/** Creates a new instance of CountData */ b/.EA'/
public CountBean() {} =Cf@!wZ^
public void setCountType(String countTypes){ d^?e*USh
this.countType=countTypes; |(x%J[n0+
} SgQmR#5
public void setCountId(int countIds){ -"Kjn`8
this.countId=countIds; Zu#^a|PE*
} <AVWT+,
public String getCountType(){ }6u}?>S
return countType; MIr[_
} 7KC2%s#7
public int getCountId(){ .gNJY7`b
return countId; qu1! KS
} %A
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} Y"5FK
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CountCache.java A5fzyG
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/* 'yOx&~H]
* CountCache.java }rVLWt
* C]ho7qC
* Created on 2007年1月1日, 下午5:01 qzY:>>d'
* s Fk{Tv@Yz
* To change this template, choose Tools | Options and locate the template under 'u PI~l`g
* the Source Creation and Management node. Right-click the template and choose JvT#Fxj k
* Open. You can then make changes to the template in the Source Editor. @B+8' b$9
*/ y\6C9%.
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package com.tot.count; qoQ,3&<
import java.util.*; wMm+E "}W
/** &_QD1 TT
* Nsy>qa7
* @author h/aG."U
*/ G^P9_Sw]d3
public class CountCache { ,
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public static LinkedList list=new LinkedList(); rIv#YqT
/** Creates a new instance of CountCache */ F9_X^#%L
public CountCache() {} Ka{QjW!%d<
public static void add(CountBean cb){ suX^"Io%!
if(cb!=null){ [mUC7Kpi
list.add(cb); q 3,p=ijJ
} JDpW7OrDc
} F%ukT6xp
} v{SYz<(
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CountControl.java U z)G Y
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/* FGMYpapc~
* CountThread.java QSYKYgxC
* `+(JwQC4
* Created on 2007年1月1日, 下午4:57 EffU-=?%!
* }z-)!8vF
* To change this template, choose Tools | Options and locate the template under kzKQ5i $G
* the Source Creation and Management node. Right-click the template and choose W}^>lM\8
* Open. You can then make changes to the template in the Source Editor. on\ahk, y]
*/ jA3Ir;a
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package com.tot.count; Qmv8T
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import tot.db.DBUtils; :$^sI"hO
import java.sql.*; A{hST~s
/** }N3Ur~X\
* _rUsb4r
* @author x5yZ+`Gc
*/ yle~hL
public class CountControl{ a^L'- (
private static long lastExecuteTime=0;//上次更新时间 FbPoyh
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 t-hN4WKH_A
/** Creates a new instance of CountThread */ !\Q/~p'jS
public CountControl() {} _l]rt
public synchronized void executeUpdate(){ W<H^V"^
Connection conn=null;
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PreparedStatement ps=null; 1z8AK"8
try{ 0j-;4>p
conn = DBUtils.getConnection(); 4mWT"T-8
conn.setAutoCommit(false); aj]%c_])(
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 0 KWi<G1
for(int i=0;i<CountCache.list.size();i++){ 5r\Rfma
CountBean cb=(CountBean)CountCache.list.getFirst(); KMkX0+Ao
CountCache.list.removeFirst(); ~o/e0
ps.setInt(1, cb.getCountId()); J@9E20$
ps.executeUpdate();⑴ <Y#EiC.
//ps.addBatch();⑵ x6~`{N1N
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} / ='/R7~
//int [] counts = ps.executeBatch();⑶ z:tu_5w!,
conn.commit(); [~rBnzb
}catch(Exception e){ j0K}nS\ P
e.printStackTrace(); ~Ywt o
} finally{ P-lE,X
try{ ^p7Er!
if(ps!=null) { cM+s)4TPL
ps.clearParameters(); d,).O
ps.close(); T EqCoeR
ps=null;
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} =kWm9W<^
}catch(SQLException e){} <j89HtCz
DBUtils.closeConnection(conn); !*|`-woE
} !TuMrA*
} Si%K|$?@
public long getLast(){ &AlX).
return lastExecuteTime; a@WSIcX*W
} c_bIadE{
public void run(){ 0~N2MoOl^
long now = System.currentTimeMillis(); 5eSmyj-W
if ((now - lastExecuteTime) > executeSep) { 9G}Crp
//System.out.print("lastExecuteTime:"+lastExecuteTime); {-Y% wM8<i
//System.out.print(" now:"+now+"\n"); xyTjK.N
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ,n?oNU
lastExecuteTime=now; `BHPjp>
executeUpdate(); W 7Y5~%@
} Mi"dFx^Md
else{ E MKv)5MH
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); /7<l`RSr
} KrT+Svm
} H@,(
} U.QjB0;
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 pVm'XP
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类写好了,下面是在JSP中如下调用。 ^cF_z}Zi+
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<% vSy#[9}
CountBean cb=new CountBean(); B?J#NFUb
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); y"SVZ} ;|
CountCache.add(cb); h"G#} C]
out.print(CountCache.list.size()+"<br>"); u($y<Q)=
CountControl c=new CountControl(); K%A:W
c.run(); %t^-Guz
out.print(CountCache.list.size()+"<br>"); $u./%JS
%>