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: c[:OK9TH
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CountBean.java dmHpF\P5f
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/* Si,[7um
* CountData.java 90)0\i+P
* {C>.fg%t
* Created on 2007年1月1日, 下午4:44 'p=5hsG
* +u%^YBr
* To change this template, choose Tools | Options and locate the template under %G6ml,
* the Source Creation and Management node. Right-click the template and choose Z:3N*YkL
* Open. You can then make changes to the template in the Source Editor. h^F^|WT$
*/ Sa!r ,l
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package com.tot.count; =M"H~;f]
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/** %liu[6_
* ^06f\7A
* @author ZhqrN]x
*/ =5NrkCk#V
public class CountBean { BIf E+L(
private String countType; NG-Wn+W@b
int countId; :'aT4
/** Creates a new instance of CountData */ 1iq,Gd-G.
public CountBean() {} Fw!wSzsk3
public void setCountType(String countTypes){ `IQ01FuP
this.countType=countTypes; Ov1$7 r@
} D>9~JHB
public void setCountId(int countIds){ rQ|^HNj
this.countId=countIds; fj
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} -<kl d+
public String getCountType(){ w=EUwt
return countType; |FZ)5
} _jK
public int getCountId(){ F&US-ce:M
return countId; f}q4~NPn-
} \F]X!#&+
} ":E^&yQ
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CountCache.java 85;
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/* 1qWIku
* CountCache.java DQ7+
* V4cCu~(3;~
* Created on 2007年1月1日, 下午5:01 $0WO
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* $o
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* To change this template, choose Tools | Options and locate the template under ~l$u~:4Ob
* the Source Creation and Management node. Right-click the template and choose &$yC+cf
* Open. You can then make changes to the template in the Source Editor. ySP1,xq
*/ _DPWp,k<~
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package com.tot.count; _2Sb?]Xn
import java.util.*; *,$cW,LN
/** pvL)BD
* )cA#2mlS'1
* @author C
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*/ +`pS 7d
public class CountCache { W.OcmA>x
public static LinkedList list=new LinkedList(); *0>![v
/** Creates a new instance of CountCache */ pME17 af
public CountCache() {} \7W>3
public static void add(CountBean cb){ e~tgd8a2a
if(cb!=null){ eELJDSd
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list.add(cb); O~t]:p9_
} gycjIy@t
} mQ 1) d5
} FEqs4<}E
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CountControl.java /Qh
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/* h2kba6rwk
* CountThread.java yWI30hW
* S/YT
V
* Created on 2007年1月1日, 下午4:57 v{%x,K56
* U5 X\RXy~
* To change this template, choose Tools | Options and locate the template under up+W[#+
* the Source Creation and Management node. Right-click the template and choose W;~ f865
* Open. You can then make changes to the template in the Source Editor. e>yPFXSk
*/ 2'O2n]{
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package com.tot.count; oNW.-gNT
import tot.db.DBUtils; a1p Z{Od
import java.sql.*; ^PwZP;On
/** >*DR>U
* Hh^EMQk
* @author }xZR`xP(
*/ wOW#A}m'vj
public class CountControl{ JbT+w\o
private static long lastExecuteTime=0;//上次更新时间 @.IGOh
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 CPJ8G}4
/** Creates a new instance of CountThread */ $~x#Q?-y
public CountControl() {} tC;LA 4
public synchronized void executeUpdate(){ % zP]z
Connection conn=null; >Z0F n
PreparedStatement ps=null; L{;Sc_
try{ zNAID-5K;
conn = DBUtils.getConnection(); JQ5E; 8J>
conn.setAutoCommit(false); jA<(#lm;
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); JmMB=}
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for(int i=0;i<CountCache.list.size();i++){ 'p%aHK{
CountBean cb=(CountBean)CountCache.list.getFirst(); @bPR"j5D
CountCache.list.removeFirst(); E}^np[u7
ps.setInt(1, cb.getCountId()); hw2'.}B"(
ps.executeUpdate();⑴ \X3Q,\H
@
//ps.addBatch();⑵ ?vA)F)MS
} Vq8 G( <77
//int [] counts = ps.executeBatch();⑶ !VLk|6mn
conn.commit(); k2bjBAT
}catch(Exception e){ ibzcO,c
e.printStackTrace(); ALcin))+B
} finally{ ;Dh\2! sr
try{ .AB n$ml]
if(ps!=null) { DIsK+1
ps.clearParameters(); kSW=DE|#}
ps.close(); Iax-~{B3AY
ps=null; v,T:V#f^
} dh9Qo4-{
}catch(SQLException e){} =*0KH##%$
DBUtils.closeConnection(conn); "0*yD[2
} h#hx(5"6
} 9Wu c1#
public long getLast(){ ON(OYXj
return lastExecuteTime; t`M4@1S"'
} 7pllzy
public void run(){ 1iA0+Ex(j
long now = System.currentTimeMillis(); G3.*fSY$.<
if ((now - lastExecuteTime) > executeSep) { $Cgl$A
//System.out.print("lastExecuteTime:"+lastExecuteTime); W8blHw"
//System.out.print(" now:"+now+"\n"); V8w7U:K
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 34*73WxK
lastExecuteTime=now; MQc<AfW3/
executeUpdate(); RGu`Jk
} kC,=E9)O
else{ -1_WE/Ps
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); us5<18M5
} vU,V[1^a
} 3# g"Z7/
} ^l:~r2
//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 =,BDd$e
3 as~yF0
类写好了,下面是在JSP中如下调用。 ]8n*f o2#
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<% /IxoS
CountBean cb=new CountBean(); JpRn)e'Z
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); E"O6N.}.
CountCache.add(cb); A`B>fI
out.print(CountCache.list.size()+"<br>"); sH'IA~7
CountControl c=new CountControl(); @3w6!Sgh
c.run(); 7z2Q!0Sz
out.print(CountCache.list.size()+"<br>"); &lCOhP#
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