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: >s;oOo+5
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CountBean.java k&WUv0
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/* Dq{:R
* CountData.java ~&t!$
* DxE(9j
* Created on 2007年1月1日, 下午4:44 i:C.8hmAE
* ;+TMx(
* To change this template, choose Tools | Options and locate the template under 7ESN!
* the Source Creation and Management node. Right-click the template and choose &\JK%X.Jlt
* Open. You can then make changes to the template in the Source Editor. /TzNdIv
*/ Q1aHIc
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package com.tot.count; " ]aQ Hh]f
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/** 3X,]=f@_
* vEu
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* @author xylpiSJ
*/ [Bl
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public class CountBean { E~'q?LJOB
private String countType; 1,m\Q_
int countId; ) ~ l\
/** Creates a new instance of CountData */ VI(RT-S6
public CountBean() {} >`<Ued
public void setCountType(String countTypes){ Mr$# e
this.countType=countTypes; aeEw#
} OG0r4^6Ly
public void setCountId(int countIds){ ^RY n8I
this.countId=countIds; lF0K=L
} d\v$%0
public String getCountType(){ elN{7:
return countType; <FCj)CP%
} suA+8}o]
public int getCountId(){ :({-0&&_
return countId; }rO?5
} r~8D\_=s
} q>Q:X3
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CountCache.java $KoPGgC[
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/* |^YzFrc
* CountCache.java C!oS=qK?]
* .}IK}A/-
* Created on 2007年1月1日, 下午5:01 >+yqjXRzm
* F% F
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* To change this template, choose Tools | Options and locate the template under Fg_?!zR>6
* the Source Creation and Management node. Right-click the template and choose K<$wz/\
* Open. You can then make changes to the template in the Source Editor. It#h p,@e
*/ |
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package com.tot.count; :iP>z}h
import java.util.*; SQ1M4:hP
/** M'pb8jf
* jlYD~)
* @author FZ[@])B
*/ A8=e?%
public class CountCache { [5>S-Z
public static LinkedList list=new LinkedList(); \[Sm2/9v
/** Creates a new instance of CountCache */ 0_YxZS\
public CountCache() {} BP )q6?Mz
public static void add(CountBean cb){ BSx j~pun
if(cb!=null){ AyQS4A.s[
list.add(cb); tQNk=}VR7r
} i /O1vU#
} [W^6u7~
} o0,UXBx
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CountControl.java T0@](g
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/* aukk|/3Ih
* CountThread.java w.4u=e >Z4
* \zk?$'d
* Created on 2007年1月1日, 下午4:57 r1[E{Tpz
* RB S[*D
* To change this template, choose Tools | Options and locate the template under ,pQ'w7
* the Source Creation and Management node. Right-click the template and choose MgJ%26TZ
* Open. You can then make changes to the template in the Source Editor. 3a'Rs{qxn
*/ v#Cz&j
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package com.tot.count; 37j\D1Y
import tot.db.DBUtils; eT7!a']x
import java.sql.*; t9Enk!@
/** *r)zBr
* 21[K[ %
* @author tnQR<
*/ uM6CG0
public class CountControl{ (PCimT=5
private static long lastExecuteTime=0;//上次更新时间 |<|28~#
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 n/9 LRZD|w
/** Creates a new instance of CountThread */ ^ l]]qdNr
public CountControl() {} =:xV(GK}
public synchronized void executeUpdate(){ 'Z*\1Ci
Connection conn=null; u)q2YLK8
PreparedStatement ps=null; e3yorQ][
try{ 5PPPd-'Z_
conn = DBUtils.getConnection(); _H~pH7WU
conn.setAutoCommit(false); @Og\SZhn
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); @{J!6YGh
for(int i=0;i<CountCache.list.size();i++){ N.fQ7z=Z(M
CountBean cb=(CountBean)CountCache.list.getFirst(); "e1{V8
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CountCache.list.removeFirst(); hj^G}4
ps.setInt(1, cb.getCountId()); E5,%J
ps.executeUpdate();⑴ ?~VWW<lR
//ps.addBatch();⑵ VfL]O 8P>
} 6=Y3(#Ddt
//int [] counts = ps.executeBatch();⑶ c]AKeq]
conn.commit(); mhHA!:Y
}catch(Exception e){ rd&*j^?
e.printStackTrace(); 8{}Pj
} finally{ ZI2K-z'e
try{ gmF_~"^34
if(ps!=null) {
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ps.clearParameters(); h/0<:eZ*
ps.close(); w%i+>\tO
ps=null; X_-Hrp!h
} D-TNFYYy2
}catch(SQLException e){} 1=9qAp;?o
DBUtils.closeConnection(conn); r+{!@`dYi
} #hy5c,}>
} ugIm:bg&
public long getLast(){ 38x[Ad4%
return lastExecuteTime; ^D]7pe
} 9[t]]
public void run(){ ({d,oU$>y
long now = System.currentTimeMillis(); dvg;
if ((now - lastExecuteTime) > executeSep) { x*loACee.
//System.out.print("lastExecuteTime:"+lastExecuteTime); GsP@ B'
//System.out.print(" now:"+now+"\n"); OBKC$e6I
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); vxbH^b
lastExecuteTime=now; }<5\O*kX4
executeUpdate(); b:}wR*Adc
} bik] JIM
else{ dUsJv
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); /?.r!Cp
} JqVBT+:
} _H^^2#wc/
} HobGl0<y
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 N[+o[%A
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类写好了,下面是在JSP中如下调用。 d+YVyw.z
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<% \jF" nl
CountBean cb=new CountBean(); vc>^.#7
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ??$i*
CountCache.add(cb); BRo
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out.print(CountCache.list.size()+"<br>"); eLDL "L
CountControl c=new CountControl(); +,vJ7
c.run(); 8T>3@kF
out.print(CountCache.list.size()+"<br>"); uNPD~TYN
%>