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: $b<6y/"
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CountBean.java &q`q4g&7
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/* F[4;Xq
* CountData.java 0vVV%,v
* {0;3W7
* Created on 2007年1月1日, 下午4:44 iSFuT7;%
* LY[~Os W
* To change this template, choose Tools | Options and locate the template under xGU(n_Y
* the Source Creation and Management node. Right-click the template and choose Qc[3Fq,f
* Open. You can then make changes to the template in the Source Editor. S a4W`
*/ kN%MP6? J
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package com.tot.count; A<6%r7&B'
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/** eeHP&1= 7
* S.Z9$k%
* @author M[ z)6.
*/ 3Wwj p
public class CountBean { UG'bOF4
private String countType; Wm H~m k"
int countId; :> & fV
/** Creates a new instance of CountData */ <\0vR20/
public CountBean() {} 6Z`R#d #I
public void setCountType(String countTypes){ Cn>ADWpT&
this.countType=countTypes; k^ YO%_
} <5G{"U+ \
public void setCountId(int countIds){ .`7cBsXH
this.countId=countIds; d/}SAvtt
} 8/t$d#xHI
public String getCountType(){ /'Pd`Nxl.
return countType; 'S[++w?Qq
} RJy=pNztm
public int getCountId(){ VR
return countId; ]r3Kg12Mi
} `+t.!tv!
} U|HB=BP
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CountCache.java h?-#9<A
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/* GZ{]0$9I'
* CountCache.java \`, [)`
* _BFOc>0
* Created on 2007年1月1日, 下午5:01 pDQ}*
* lc_E!"1
* To change this template, choose Tools | Options and locate the template under pA;-vMpMj
* the Source Creation and Management node. Right-click the template and choose jqH3J2L
* Open. You can then make changes to the template in the Source Editor. `]LSbS
*/ G60R9y47c
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package com.tot.count; hLDA]s
import java.util.*; /T,Z>R
/** RUr=fEH
* saU]`w_Z*
* @author ,*]d~Y
*/ 2"fO6!hh
public class CountCache { ^'p|!`:
public static LinkedList list=new LinkedList(); k'$!(*]\b
/** Creates a new instance of CountCache */ bln/1iS
public CountCache() {} k8,?hX:
public static void add(CountBean cb){ s/:Fwr4q#a
if(cb!=null){ *cTO7$\[
list.add(cb); U$H@ jJ*
} # wc \T
} k z"3ZDR
} *WE1;msr
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CountControl.java _U{([M>;
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/* -o+74=E8[?
* CountThread.java =pA
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* +3i7D
* Created on 2007年1月1日, 下午4:57 },5'z{3E
* >K# ,cxY
* To change this template, choose Tools | Options and locate the template under =`Y.=RL+'n
* the Source Creation and Management node. Right-click the template and choose Y~)T
* Open. You can then make changes to the template in the Source Editor. ^uS/r#l
*/ >xA),^ YT
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package com.tot.count; 577:u<Yt
import tot.db.DBUtils; NZN-^ >
import java.sql.*; hI pKJ&hm
/** F?m?UQS'u
* zq1mmFIO
* @author VR!-%H\AW
*/ 51#"3S
public class CountControl{ }X;U|]d
private static long lastExecuteTime=0;//上次更新时间 qn"D#K'&(
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Dml*T(WM>
/** Creates a new instance of CountThread */ XJ!(F#zc
public CountControl() {} iqhOi|!
public synchronized void executeUpdate(){ G5D2oQa=8
Connection conn=null; d bS
+
PreparedStatement ps=null; '!Gs>T+
try{ 0W`LVue
conn = DBUtils.getConnection(); F8e<}v&7R
conn.setAutoCommit(false); i#X!#vyc
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); fag^7r z
for(int i=0;i<CountCache.list.size();i++){ 7n)&FXK`
CountBean cb=(CountBean)CountCache.list.getFirst(); Q,Z*8FH=
CountCache.list.removeFirst(); `(0LK%w
ps.setInt(1, cb.getCountId()); 91of~ffh
ps.executeUpdate();⑴ ==/n(LBD
//ps.addBatch();⑵ ha;l(U>
} "Lh
//int [] counts = ps.executeBatch();⑶ PN$
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conn.commit(); i`)!X:j
}catch(Exception e){ tvX>{-M
e.printStackTrace(); G6K
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} finally{ JNWg|Qt
try{ K?#]("De6
if(ps!=null) { /w]&t\]*
ps.clearParameters(); bg?"ILpk
ps.close(); I\\QS.2
ps=null; 9umGIQHnil
} >EXb|vw
}catch(SQLException e){} v&g0ta@
DBUtils.closeConnection(conn); gQ~5M'#
} g8ES8SM
} ^IgY d*5
public long getLast(){ jnuY{0(&
return lastExecuteTime; nzX@:7g
} @\(v X ]
public void run(){ ?IX!+>.H
long now = System.currentTimeMillis(); Fk^3a'/4KJ
if ((now - lastExecuteTime) > executeSep) { 8_uzpeRhJc
//System.out.print("lastExecuteTime:"+lastExecuteTime); o@lWBfB*%e
//System.out.print(" now:"+now+"\n"); 5 waw`F
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); DhI>p0* T
lastExecuteTime=now; *.f2VQ~H
executeUpdate(); >+cVs:
} ~9D~7UR
else{ 1xnLB>jP#
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); G>T')A
} tJ&5tNl
} A%Z)wz{
} (}!C4S3#
//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 (#(Or
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类写好了,下面是在JSP中如下调用。 yy2Ie
S"snB/
<% TTI81:fku
CountBean cb=new CountBean(); =OTm2:j#yQ
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); i}TwOy<4s
CountCache.add(cb); xPmN},i'R$
out.print(CountCache.list.size()+"<br>"); BOf1J1
CountControl c=new CountControl(); lm'Zy"~::
c.run(); z&nZ<ih
out.print(CountCache.list.size()+"<br>"); `GQ{*_-
%>