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: `u-Y 5mY
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CountBean.java ,U}8(D~:
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/* b%(0AL
* CountData.java <>TBM^
* yyc&'J
* Created on 2007年1月1日, 下午4:44 3B+Rx;>h
* O9Aooe4W=
* To change this template, choose Tools | Options and locate the template under \=)h6AG
* the Source Creation and Management node. Right-click the template and choose r+Y1m\
* Open. You can then make changes to the template in the Source Editor. jk@]d5
*/ d<o
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package com.tot.count; YQ/*|
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/** _PF><ODX2
* q2y:bqLWl
* @author V|=
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*/ .;'xm_Gw<
public class CountBean { AO6;aT
private String countType; jo;n~>3P
int countId; <S
qbj;
/** Creates a new instance of CountData */ b~}}{fm&f
public CountBean() {} s6I]H
public void setCountType(String countTypes){ Ts\7)6|F
this.countType=countTypes; 6C:Lq%}
} >qCT#TY
public void setCountId(int countIds){ 6x 0>E^~
this.countId=countIds; hjE9[{K
} 1K>4i. X
public String getCountType(){ Rjf|
return countType; ?k#%AM
} 8Bhng;jX
public int getCountId(){ u8*0r{kOH
return countId; r"+
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} kcle|B
} 7j+.H/2
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CountCache.java vzL>ZBeZ
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/* <FP-]R)
* CountCache.java 39"'Fz?1
* f]Vz !hM~
* Created on 2007年1月1日, 下午5:01 N|DY)W
* eMs`t)rQ
* To change this template, choose Tools | Options and locate the template under sb1/4u/W
* the Source Creation and Management node. Right-click the template and choose `f s[C
* Open. You can then make changes to the template in the Source Editor. vI-KH:r"{
*/ &>-Cz%IV
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package com.tot.count; $jHL8r\e7
import java.util.*; -Je+7#P1
/** rP'oUV_
* &+\wYa,
* @author I
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*/ o}T]f(>}
public class CountCache { IAfYlS#<yD
public static LinkedList list=new LinkedList(); .D :v0Zm}m
/** Creates a new instance of CountCache */ tQ/U'Ap&
public CountCache() {} er53?z7zP.
public static void add(CountBean cb){ .}tL:^'~o
if(cb!=null){ HV}NT~
list.add(cb); &c]x;#-y
} ;j$84o{
} 8)i\d`
} ,"D1!0
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CountControl.java R{T4AZ@,'
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/* .m<-)Kx
* CountThread.java BjA|H
* g$A1*<+
* Created on 2007年1月1日, 下午4:57 W?@ ;(k
* 7l?=$q>k"
* To change this template, choose Tools | Options and locate the template under E( TY%wO
* the Source Creation and Management node. Right-click the template and choose b`^$2RM&
* Open. You can then make changes to the template in the Source Editor. +G?3j ,a\
*/ )T>a|.
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package com.tot.count; @-hy:th#
import tot.db.DBUtils; r@_;L>
import java.sql.*; 8'zwyd3
/** c6e?)(V>
* X3nwA#If1
* @author a@%FwfIu
*/ 2W}RXqV<
public class CountControl{ =%a.C(0&G
private static long lastExecuteTime=0;//上次更新时间 &P\T{d2"
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 _8bqk\m+
/** Creates a new instance of CountThread */ 46mu,v
public CountControl() {} j*CnnM#n
public synchronized void executeUpdate(){ tvd/Y|bV=
Connection conn=null; )&*&ZL0
PreparedStatement ps=null; Jap
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try{ 0hPm,H*Y]
conn = DBUtils.getConnection(); .9`.\v6R
conn.setAutoCommit(false); 0py0zE6,,
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); @.%ll n
for(int i=0;i<CountCache.list.size();i++){ g
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CountBean cb=(CountBean)CountCache.list.getFirst(); +jHL==W&
CountCache.list.removeFirst(); U7{,
*
ps.setInt(1, cb.getCountId()); >:Rc%ILym
ps.executeUpdate();⑴ b+w|3bQa
//ps.addBatch();⑵ #KiRH* giU
} ^fRA$t
//int [] counts = ps.executeBatch();⑶ AR&u9Y)I
conn.commit(); ]Fa VKC~3
}catch(Exception e){ GLEGyT?~
e.printStackTrace(); zhFGMF1
} finally{ %R}}1
try{ Rrs z{a
if(ps!=null) { UA{A G;
ps.clearParameters(); r l!c\
ps.close(); `DEz `
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ps=null; 3xeW!~
} zV%U4P)Dao
}catch(SQLException e){} _m;Y'
DBUtils.closeConnection(conn); M7hff4c
} 63ht|$G
} RsY|V|<
public long getLast(){ `?~pk)<C].
return lastExecuteTime; 9HWtdJ+^C=
} si)920?E&
public void run(){ \vKMNk;kz
long now = System.currentTimeMillis(); =T9QmEBm
if ((now - lastExecuteTime) > executeSep) { $LKniK
//System.out.print("lastExecuteTime:"+lastExecuteTime); 92XzbbLp
//System.out.print(" now:"+now+"\n"); uQrD}%GI
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); f\1)BZ'I
lastExecuteTime=now; nd-y`@z
executeUpdate(); %|4Nmf$:Og
} `NrxoU=
else{ ]Rz]"JZ\S
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); $dq
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} e3&R3{
} Rs7=v2>I
} &d=j_9
//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 ~fEgrF d
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类写好了,下面是在JSP中如下调用。 TN(1oJ:
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<% wQDKv'zU1
CountBean cb=new CountBean(); |6$6Za]:
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); mI@]{K}Q%
CountCache.add(cb); L=
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out.print(CountCache.list.size()+"<br>"); @MTm8E6au
CountControl c=new CountControl(); <!R~G-D#_T
c.run(); 0zetOlFbO
out.print(CountCache.list.size()+"<br>"); $GEY*uIOa
%>