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: $v`afd y
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CountBean.java G|m1.=DJm
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/* lg}HGG
* CountData.java Z/6qG0feJ
* `$604+G
* Created on 2007年1月1日, 下午4:44 Fa epDjY8
* S\wW)Pv8
* To change this template, choose Tools | Options and locate the template under E"|4Y(G
* the Source Creation and Management node. Right-click the template and choose }6-ZE9H-v
* Open. You can then make changes to the template in the Source Editor. @f!AkzI
*/ 5 #]4YI;
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package com.tot.count; $ C0TD7=
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/** a{!r`>I\f
* -z:&*=
* @author &48_2Q"{
*/ f{lZKfrp
public class CountBean { oA
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private String countType; 3"UsZyN:
int countId; %gcc
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/** Creates a new instance of CountData */ p\bFdxv#
public CountBean() {} 1j\aH&)GH
public void setCountType(String countTypes){ O}#yijU3e
this.countType=countTypes; @-#T5?
} IC{F.2D
public void setCountId(int countIds){ np WEop>
this.countId=countIds; M8@_Uj
} sl/)|~3!8
public String getCountType(){ S*)o)34U
return countType; #^&jW
} 1Qh`6Ya f
public int getCountId(){ z]Acs
return countId; HXJ9xkrr
} {$^SP7qV#>
} {6x PdUhw
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CountCache.java TK>{qxt:=
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/* .}9FEn 8
* CountCache.java (Q-I8Y8l8
* sIm#_+Y
* Created on 2007年1月1日, 下午5:01 djT.
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* 2[dIOb4b
* To change this template, choose Tools | Options and locate the template under %^9:%ytt
* the Source Creation and Management node. Right-click the template and choose !%mi&ak(Rn
* Open. You can then make changes to the template in the Source Editor. H2Eb\v`#
*/ >$F:*lO
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package com.tot.count; #@Ujx_F
import java.util.*; ;IC'Gq
/** W3LP
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* NygI67
* @author IMad$AKc
*/ "E>t,
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public class CountCache { ARx0zI%N
public static LinkedList list=new LinkedList(); 3#Y3Dz`
/** Creates a new instance of CountCache */ $o^e:Y,
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public CountCache() {} 0RyFv+
public static void add(CountBean cb){ (5;D7zdA
if(cb!=null){ u3Do~RyL[
list.add(cb); <lOaor
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} S!7g)
} f[qPG&
} {Bvm'lq`
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CountControl.java :l~E E!
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/* /{DaPqRa
* CountThread.java T_~KxQ
* vOgLEN&]
* Created on 2007年1月1日, 下午4:57 -SJSTO[/J
* &r:m&?!|VQ
* To change this template, choose Tools | Options and locate the template under v[D&L_
* the Source Creation and Management node. Right-click the template and choose 6_U|(f
* Open. You can then make changes to the template in the Source Editor. m;h<"]<
*/ kV1vb
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package com.tot.count; !~d'{sy6
import tot.db.DBUtils; bp Ml =_
import java.sql.*; 6To:T[ z#
/** ?48AY6
* s$3`X(Pn
* @author BVAr&cu
*/ .\)k+ R
public class CountControl{ <~O}6HQ#
private static long lastExecuteTime=0;//上次更新时间 \c68n
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 0h:G4
/** Creates a new instance of CountThread */ C.HYS S
public CountControl() {} XSl!T/d
public synchronized void executeUpdate(){ 8;8YA1@w
Connection conn=null; 9ET/I$n
PreparedStatement ps=null; bpnv &EG
try{ cdN/Qy
conn = DBUtils.getConnection(); *pK lA&_
conn.setAutoCommit(false); @% H8"A
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); CfY7<o1>
for(int i=0;i<CountCache.list.size();i++){ Ym:{Mm=ud
CountBean cb=(CountBean)CountCache.list.getFirst(); C{)HlOW
CountCache.list.removeFirst();
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ps.setInt(1, cb.getCountId()); blmmm(|~|
ps.executeUpdate();⑴ Lb^(E-
//ps.addBatch();⑵ rd|crD3
} yIa[yJq
//int [] counts = ps.executeBatch();⑶ K@*rVor{
conn.commit(); )+*{Y$/U
}catch(Exception e){ \boL`X
e.printStackTrace(); U81;7L8
} finally{ .
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try{ O!yakU+
if(ps!=null) { /4^G34
ps.clearParameters(); s{cKBau
ps.close(); 2H3(HZv
ps=null; srsK:%`
} 2k+=kt
}catch(SQLException e){} .E#<fz
DBUtils.closeConnection(conn); zdqnL^wb
} ^W5>i[
} rQn{L{
public long getLast(){ 6TY){Pw
return lastExecuteTime; yS+(<
} L)1C'8).
public void run(){ 70duk:Ri0
long now = System.currentTimeMillis(); P&,hiGTDi
if ((now - lastExecuteTime) > executeSep) { G&.d)NfE
//System.out.print("lastExecuteTime:"+lastExecuteTime); EZ..^M3
//System.out.print(" now:"+now+"\n"); 32s5-.{c/f
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); IvFR <n
lastExecuteTime=now; )-)ss"\+Ju
executeUpdate(); g)X7FxS,z
} Xm%iPrl D
else{ (rAiDRQ[
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); +O&RBEa[
} 3Ca
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} E]\D>[0O
} #"hJpyW 4V
//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 Akv(} !g
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类写好了,下面是在JSP中如下调用。 *1\z^4=a]
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<% n?zbUA#
CountBean cb=new CountBean(); i5.?g <.H
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); u82h6s<'W
CountCache.add(cb); f3/SO+Me}
out.print(CountCache.list.size()+"<br>"); &t~zD4u B
CountControl c=new CountControl(); <9ePi9D(
c.run(); hU 9\y
out.print(CountCache.list.size()+"<br>"); N 9c8c
%>