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: =*:_swd
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CountBean.java zpr@!76
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/* n.XhK_6n]M
* CountData.java 4J
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* dtnet_j
* Created on 2007年1月1日, 下午4:44 p vQK6r
* >g"M.gW
* To change this template, choose Tools | Options and locate the template under ^8l3j4
* the Source Creation and Management node. Right-click the template and choose 3?Eoj95w!
* Open. You can then make changes to the template in the Source Editor. $gl<{{
*/ $#ju?B~
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package com.tot.count; N|O]z
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/** n$|c{2]=
* .0fh>kQ
* @author 9}jq`xSL
*/ R~5*#r@f
public class CountBean { SM#S/|.]
private String countType; CndgfOF
int countId; 27 145
/** Creates a new instance of CountData */ ;!JX-J q
public CountBean() {} i$^B-
public void setCountType(String countTypes){ Q$h:[_v
this.countType=countTypes; "3i80R\w`F
} _X2EBpZp
public void setCountId(int countIds){ fxoi<!|iGY
this.countId=countIds; Ag4Ga?&8ec
} -6~y$c&c
public String getCountType(){ Z'*Z@u3
return countType; 7kX$wQZ_
} !MJe+.
public int getCountId(){ ,Lun-aMd
return countId; ;y~{+{{Ow
} "`i:)E t
} D@\;@(
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CountCache.java c6Aut`dK
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/* ^L-w(r62<
* CountCache.java r2GK_$vd
* r -q3+c^+
* Created on 2007年1月1日, 下午5:01 z'oiyXEE3
* ){
* To change this template, choose Tools | Options and locate the template under }uI7\\S
* the Source Creation and Management node. Right-click the template and choose G]mWaA
* Open. You can then make changes to the template in the Source Editor. >'}=.3\
*/ h#m:Y~GoF
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package com.tot.count; pgd8`$(Q
import java.util.*; RE>ks[
/** Gl8&FrR
* O%JsUKV
* @author EwD3d0udL
*/ '-PMF~~S
public class CountCache { Vp]D
public static LinkedList list=new LinkedList(); 9XoQO 9*Q
/** Creates a new instance of CountCache */ ^K.u
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public CountCache() {} G=Hf&l
public static void add(CountBean cb){ t`Y!"l
if(cb!=null){ GT'7,+<?N
list.add(cb); Zv| p>q`R2
} 0939i_
} /j' B\,
} F?8BS*r_
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CountControl.java *j/S4qG
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/* )Ab6!"'
* CountThread.java 6hM]%
* sp=OT-Pfp
* Created on 2007年1月1日, 下午4:57 )W`SC mr]
* ',JrY)
* To change this template, choose Tools | Options and locate the template under 4N~+G `
* the Source Creation and Management node. Right-click the template and choose ,'C30 A*p
* Open. You can then make changes to the template in the Source Editor. v.Xoq
*/ $Eio$TI
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package com.tot.count; xEVLE,*?>
import tot.db.DBUtils; JvfQib
import java.sql.*; oe!:|ck<
/** 7}?k^x,1
* 2f|6z-Z
* @author OQ(D5GR:4
*/ \9] I#Ih}M
public class CountControl{ LZM,QQ
private static long lastExecuteTime=0;//上次更新时间 \T`["<
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 .73zik
/** Creates a new instance of CountThread */ hhpv\1h#
public CountControl() {} G [3k
public synchronized void executeUpdate(){ 6x_T@
Connection conn=null; 4L5o\'X
PreparedStatement ps=null; ieo|%N{'
try{ Z&FkLww
conn = DBUtils.getConnection(); x"
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conn.setAutoCommit(false); K DYYB6|
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); {)V? R
for(int i=0;i<CountCache.list.size();i++){ 4l&"]9D
CountBean cb=(CountBean)CountCache.list.getFirst(); gEv-> pc
CountCache.list.removeFirst(); =n-z;/NL
ps.setInt(1, cb.getCountId()); ohrw\<xsu
ps.executeUpdate();⑴ g4:VR:o
//ps.addBatch();⑵ %5JW<9
} -B1YZ/.rz"
//int [] counts = ps.executeBatch();⑶ co5y"yj_
conn.commit(); xfq]9<
}catch(Exception e){ nW4Vct
e.printStackTrace(); z,{e]MB)M
} finally{ u12zRdn
try{ 8RdP:*HY
if(ps!=null) { E@w[
ps.clearParameters(); 'h-3V8m^e
ps.close(); O)`fvpVU
ps=null; Bx(yu'g|a
} ! FNf>z+
}catch(SQLException e){} 5x8'K7/4.
DBUtils.closeConnection(conn); YywEZ?X
} ],8;eq%W)
} E:
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public long getLast(){ %
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return lastExecuteTime; iQt!PMF.
} cYGRy,'gH
public void run(){ 2B7h9P.N B
long now = System.currentTimeMillis(); ,e9CJ~a
if ((now - lastExecuteTime) > executeSep) { u8Y~_)\MA
//System.out.print("lastExecuteTime:"+lastExecuteTime); '#v71,
//System.out.print(" now:"+now+"\n"); XQ]`&w(
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); #gh
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lastExecuteTime=now; ngP7'1I
executeUpdate(); _6;<ow
} NB EpM
else{ $ye^uu;Z
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); xXF2"+
} (NX)oP
} ajW[eyX
} nV'3sUvR#
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 [#p&D~Du&
>DL/..
类写好了,下面是在JSP中如下调用。 ~}BJ0P(VMc
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<% W1vCN31
CountBean cb=new CountBean(); Fse['O~
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); eY
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CountCache.add(cb); 9"~9hOEct
out.print(CountCache.list.size()+"<br>"); #wF1
CountControl c=new CountControl(); Dy su{rL
c.run(); p ZtgIS(3
out.print(CountCache.list.size()+"<br>"); lLH$`Wnv
%>