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: iMP*]K-O
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CountBean.java ?Ry%c6(}
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/* bd@*vu}?}
* CountData.java yS1b,cxz
* va`l*N5
* Created on 2007年1月1日, 下午4:44 q[PD
* ?Zc/upd:$N
* To change this template, choose Tools | Options and locate the template under Fw(b1 d>E
* the Source Creation and Management node. Right-click the template and choose g:G%Ei~sF
* Open. You can then make changes to the template in the Source Editor. xI/{)I1f
*/ mB{&7Rb0
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package com.tot.count; hqhu^.}]
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/** .}L-c>o"o
* VJ~X#Q
* @author }}4sh5z
*/ r`&2-]
public class CountBean { Gvt;Q,hH
private String countType; BR&Qw'O%
int countId; yr/]xc$
/** Creates a new instance of CountData */ O<eWq]
public CountBean() {} UX-_{I
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public void setCountType(String countTypes){ VuX>
this.countType=countTypes; !I~C\$^U
} Z1)jRE2dl
public void setCountId(int countIds){ xN{"%>Mx
this.countId=countIds; Dr8WV\4@
} d'lr:=GQ
public String getCountType(){ 7\\~xSXh
return countType; ex@,F,u>o
} h a,=LV
public int getCountId(){ yL.PGF1(
return countId; -H ac^4uF
} U- *8%>Qp
} W|r+J8
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CountCache.java P/C+L[X=
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/* g "K#&
* CountCache.java #Vn>ue+?
* azR;*j8Q'
* Created on 2007年1月1日, 下午5:01 QKUBh-QFK
* 6h0U
* To change this template, choose Tools | Options and locate the template under 9rpg1 0/T
* the Source Creation and Management node. Right-click the template and choose He0N
* Open. You can then make changes to the template in the Source Editor. T/WmS?
*/ St~SiTJU
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package com.tot.count; ; mo\ yW1
import java.util.*;
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/** ]JqkC4|
* MW",r;l<aM
* @author :EQme0OW
*/ bD-/ZZz
public class CountCache { JK:mQ_
public static LinkedList list=new LinkedList(); qj3bt_F!x
/** Creates a new instance of CountCache */ ~J. Fl[
public CountCache() {} <*r<+S
public static void add(CountBean cb){ Ip7FD9
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if(cb!=null){ RaM#@D7
list.add(cb); S$lmEJ_
} $ )TF,-#x
} M::IE|h
} YPff)0Nh
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CountControl.java {Hp}F!X$
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/* `6BS-AVO7
* CountThread.java z?t(+^
* WKrZTPD'm
* Created on 2007年1月1日, 下午4:57 wD?=u\% &
* .e
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* To change this template, choose Tools | Options and locate the template under 0Yzb=QMD
* the Source Creation and Management node. Right-click the template and choose "!6 B5Oz
* Open. You can then make changes to the template in the Source Editor. J!
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*/ `Z7ITvF>
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package com.tot.count; +/>YH-P=
import tot.db.DBUtils; DCt:EhC
import java.sql.*; Bc|x:#`C\{
/** \]`(xxt1
* +|"n4iZ!)
* @author mQA<t)1
*/ qnfRN'
public class CountControl{ A%m`LKV~@
private static long lastExecuteTime=0;//上次更新时间 J,=E5T}U^
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 hTtp-e`
/** Creates a new instance of CountThread */ ='bmjXu
public CountControl() {} k+R?JWC:
public synchronized void executeUpdate(){ yxP ?O@(
Connection conn=null; \lbiz4^>
PreparedStatement ps=null; \IZ4( Z
try{ Tvx8l
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conn = DBUtils.getConnection(); (&]15 FJ$1
conn.setAutoCommit(false); &G,o guo
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 6% y)
for(int i=0;i<CountCache.list.size();i++){ vS t=Ax3]
CountBean cb=(CountBean)CountCache.list.getFirst(); $9i5<16
CountCache.list.removeFirst(); XX[Wwt
ps.setInt(1, cb.getCountId()); WJSHLy<a
ps.executeUpdate();⑴ s^t1PfP(,
//ps.addBatch();⑵ &?g!}Ky \
} CG>2,pP,
//int [] counts = ps.executeBatch();⑶ &N7:k+E
conn.commit(); 3F'dT[;
}catch(Exception e){ x>9EVa)
e.printStackTrace(); F.
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} finally{ +$=Wms-z
try{ OYtus7q<
if(ps!=null) { WZ6{(`;#m
ps.clearParameters(); &'yV:g3H
ps.close(); <[5$ {)
ps=null; \HQb#f,
} *-!ndbf
}catch(SQLException e){} H6JMN1#t$
DBUtils.closeConnection(conn); Jx9%8Ek
} vzm4
} E|4XQ|B@
public long getLast(){ >T*g'954xF
return lastExecuteTime; n`KXJ?t
} |AfQ_iT6c
public void run(){ \\G6c4fC
long now = System.currentTimeMillis(); ,M h/3DPgE
if ((now - lastExecuteTime) > executeSep) { ~m|?! ]n
//System.out.print("lastExecuteTime:"+lastExecuteTime); 0?Wf\7
//System.out.print(" now:"+now+"\n"); QRHm|f9_C
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 2[YD&
lastExecuteTime=now; taEMr> /
executeUpdate(); f>+}U;)EF
} wG?kcfu
else{ geN%rD
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); j p]geV54
} R"t$N@ZFb
} )* nbEZm@
} %=<NqINM[
//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 ?jm2|:
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类写好了,下面是在JSP中如下调用。 3<lhoD
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<% DJ[#H
CountBean cb=new CountBean(); f EiEfu
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); +;iesULXn
CountCache.add(cb); :(p
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out.print(CountCache.list.size()+"<br>"); <({eOh5N
CountControl c=new CountControl(); 2_\|>g|
c.run(); U`p<lxRgQ
out.print(CountCache.list.size()+"<br>"); _w/N[E
%>