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: (nwp s
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CountBean.java O+?vQ$z
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/* LP'wL6#
* CountData.java `^HK-t4q
* g3
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* Created on 2007年1月1日, 下午4:44 xpp>5d
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* \<HY'[gr
* To change this template, choose Tools | Options and locate the template under q#O8Fv
* the Source Creation and Management node. Right-click the template and choose 9$L2a
* Open. You can then make changes to the template in the Source Editor. aHdQi,=z
*/ h0?w V5H
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package com.tot.count; \30rF]F`l
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/** jp7cPpk:LG
* 8},:
* @author DLN zH
*/ Kk).KgR
public class CountBean { =gB8(1g8
private String countType; >9NC2%61S
int countId; CiV^bYi
/** Creates a new instance of CountData */ ^ib
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public CountBean() {} mqtYny'
public void setCountType(String countTypes){ iS< ^MD
this.countType=countTypes; F1t+D)KA>
} )O2IEwPd.
public void setCountId(int countIds){ SZUo RWx
this.countId=countIds; =6
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} 7h.fT`
public String getCountType(){ J@OK"%12
return countType; D\| U_>
} YkbuyUui
public int getCountId(){ *c>B-Fo/D
return countId; #;=sJ[m4
} Tol"D2cyf
} ~RH)iI
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CountCache.java Ciy%7_~\
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/* =!G{+&j
* CountCache.java B3<sSe8L0
* ~e&O?X
* Created on 2007年1月1日, 下午5:01 A&A{Thz
* /Pxny3
* To change this template, choose Tools | Options and locate the template under xE{slDl
* the Source Creation and Management node. Right-click the template and choose D/afa8>LQH
* Open. You can then make changes to the template in the Source Editor. dZo x;_b
*/ {:|b,ep
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package com.tot.count; "|Kag|(qB
import java.util.*; m@UrFPZ
/** }kF?9w
* k?rJGc G
* @author FKPR;H8>
*/ *I[tIO\
public class CountCache { J0imWluhQ
public static LinkedList list=new LinkedList(); tH~>uOZW
/** Creates a new instance of CountCache */ 4bcd=a;
public CountCache() {} p1\mjM
public static void add(CountBean cb){ /|lAxAm?
if(cb!=null){ W4bN']?
list.add(cb); o70] F
} *
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} gWL`J=DiU
} :G#+5 }
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CountControl.java {9@u:(<X9
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/* +* j8[sz
* CountThread.java ,"F0#5
* =kf"%vFV
* Created on 2007年1月1日, 下午4:57 @t;726
* \._|_+HiW
* To change this template, choose Tools | Options and locate the template under 1rS8+!9C
* the Source Creation and Management node. Right-click the template and choose $U7#3-'
* Open. You can then make changes to the template in the Source Editor. nEPTTp+B
*/ M ziOpraj
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package com.tot.count; >FKwFwT4D
import tot.db.DBUtils; Y;'SD{On
import java.sql.*; $}'(%\7"
/** ~4|Tr z2T
* 'c_K[p$
* @author l|{[vZpT
*/ nW}
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public class CountControl{ @qYT/V*/
private static long lastExecuteTime=0;//上次更新时间 a6Joa&`dv
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 )\j
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/** Creates a new instance of CountThread */ CZ'm|^S
public CountControl() {} I~6 o<HO
public synchronized void executeUpdate(){ $4}G
Connection conn=null; 'kco.
1{
PreparedStatement ps=null; 7A) E4f'
try{ X#
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conn = DBUtils.getConnection(); Ni%@bU $
conn.setAutoCommit(false); @SyL1yFX
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ->X>h_k.Y
for(int i=0;i<CountCache.list.size();i++){ \*Yr&Lm
CountBean cb=(CountBean)CountCache.list.getFirst(); N!MDD?0
CountCache.list.removeFirst(); "vT$?IoEV
ps.setInt(1, cb.getCountId()); ?D6|~k
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ps.executeUpdate();⑴ ^ g|VZN
//ps.addBatch();⑵ 6B%
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} !A1~{G2VL_
//int [] counts = ps.executeBatch();⑶ z[ 'G"yCi
conn.commit(); $PI9vyS
}catch(Exception e){ YRCs&tgs
e.printStackTrace(); + ~5P7dh6
} finally{ nI&p.i6
try{ OScqf]H
if(ps!=null) { s2GF*{
ps.clearParameters(); x$bUd 9
ps.close(); aL`wz !
ps=null; "<{|ni}
} X:I2wJDs\
}catch(SQLException e){} 3Pllxq<n
DBUtils.closeConnection(conn); hF$qH^-c*A
} jd,i=P%
} ~%C F3?e6
public long getLast(){ [0hahR
return lastExecuteTime; A)V*faD
} ~;a\S3
public void run(){ HsUh5;
long now = System.currentTimeMillis(); @K+gh#
if ((now - lastExecuteTime) > executeSep) { uo J0wG.
//System.out.print("lastExecuteTime:"+lastExecuteTime); "bDj00nwh
//System.out.print(" now:"+now+"\n"); d6ef)mw
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); >;'0ymG.`
lastExecuteTime=now; P"l'? `
executeUpdate(); Je6wio-4
} qT !lq
else{ `}KxzD
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); w/(c}%v}=
} '"\'<>Be
} eBs.RR
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} \wk;Bo
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 =JgR c7
R ZQH#+*t}
类写好了,下面是在JSP中如下调用。 zSQy
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<% M?UUT8,
CountBean cb=new CountBean(); 'j<u0'K@
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); <n 06(9BF
CountCache.add(cb); Btm_S\1
out.print(CountCache.list.size()+"<br>"); DKu$u ]Z
CountControl c=new CountControl(); z fv@<'
c.run(); H@Ot77(*
out.print(CountCache.list.size()+"<br>"); fn=A_
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%>