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: (R!.=95@
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CountBean.java 7s;*vd>
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/* iF1zLI<A
* CountData.java RMAbu*D0
* )(yKm/50
* Created on 2007年1月1日, 下午4:44 z@2nre
* mQ\oR|
* To change this template, choose Tools | Options and locate the template under TaZlfe5z
* the Source Creation and Management node. Right-click the template and choose r6kQMFA
* Open. You can then make changes to the template in the Source Editor. N
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*/ +lJD7=%K]Z
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package com.tot.count; MU1T="N^+
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/** QtOT'<2t]
* RG-,<G`
* @author ST\d-x
*/ {tnhP^C3>
public class CountBean { -i4hJC!3
private String countType; pFEU^]V3*
int countId; U"K%ip:Wd
/** Creates a new instance of CountData */ +b{tk=Q:
public CountBean() {} &>XSQB(&%
public void setCountType(String countTypes){ 5%" 0
this.countType=countTypes; [O6JVXO>
} "mcuF]7F
public void setCountId(int countIds){ _61tE
this.countId=countIds; Q>\9/DjUp
}
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public String getCountType(){ ;AT~?o`n
return countType; ts=+k/Z
} Tg v]30F)
public int getCountId(){ wA6<BujD
return countId; weIlWxy
} g+=f=5I3
} @T{I;8S
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CountCache.java EyV6uk~
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/* ;*e$k7}F
* CountCache.java I0sw/,J/Z
* 8FBXdk?A
* Created on 2007年1月1日, 下午5:01 gR k+KGKn<
* _"qX6Jc
* To change this template, choose Tools | Options and locate the template under *w1R>
* the Source Creation and Management node. Right-click the template and choose M532>+A]Za
* Open. You can then make changes to the template in the Source Editor. z4(Q.0x7
*/ \p!mX|
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package com.tot.count; {^Q1b.=
import java.util.*; >8DZj&j
/** \eS-wO7%
* "C]_pWk
* @author _^Q =n>G
*/ $9<P3J 1
public class CountCache { y?V#LW[^E
public static LinkedList list=new LinkedList(); {c=H#- A
/** Creates a new instance of CountCache */ &fwb?Vn4
public CountCache() {} >\ PNKpn{
public static void add(CountBean cb){ n}q/:|c
if(cb!=null){ N#vV;
list.add(cb); ['@R]Si"!
} 5~xv"S(E}
} 4+au6ABy
}
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CountControl.java S{)'1J_0
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/* )}T0SGY
* CountThread.java y3mJO[U0 a
* uJ%XF*> _D
* Created on 2007年1月1日, 下午4:57 oz\r0:
* %;YERO!
* To change this template, choose Tools | Options and locate the template under fvw&y+|y!
* the Source Creation and Management node. Right-click the template and choose :JG2xtn
* Open. You can then make changes to the template in the Source Editor. +q)B4A'J!
*/ 'M3V#5l)@|
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package com.tot.count; o%?~9rf]]
import tot.db.DBUtils; O`='8'6zW\
import java.sql.*; {@3p^b*E)1
/** 8Sg:HU\
* > 0NDlS%Q:
* @author OeY+Yt0
*/ ?L6ACi`9
public class CountControl{ R>`TV(W`9
private static long lastExecuteTime=0;//上次更新时间 F$H^W@<w
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 OEj%cB!
/** Creates a new instance of CountThread */ /Wm3qlv
public CountControl() {} 4(}V$#^+
public synchronized void executeUpdate(){ )Xd2qbi
Connection conn=null; F5/,H:K\
PreparedStatement ps=null; YBY!!qjPx
try{ v/}hy$7
conn = DBUtils.getConnection(); |[
,|S{
conn.setAutoCommit(false); kG]FB.@bG
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); <}^l MBa
for(int i=0;i<CountCache.list.size();i++){ K7gqF~5x~
CountBean cb=(CountBean)CountCache.list.getFirst(); N+0`Jm
CountCache.list.removeFirst(); :X~{,J
ps.setInt(1, cb.getCountId()); )x&OdFX
ps.executeUpdate();⑴ B}2 JK9
//ps.addBatch();⑵ .g95E<bd
} FR 1se
//int [] counts = ps.executeBatch();⑶ NW@guhK.
conn.commit(); .eM
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}catch(Exception e){ @P}!mdH1
e.printStackTrace(); rJ_fg$.<
} finally{ '5m`[S-IU
try{ zu|=1C#5h
if(ps!=null) { %^66(n)
ps.clearParameters(); 9Y-6e0B:
ps.close(); RF.8zea{O`
ps=null; "ku ?A ^f
} P
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}catch(SQLException e){} ixI fJ
DBUtils.closeConnection(conn); Xu#K<#V
} 5K %
} dEM=U;
public long getLast(){ iWu^m+"k
return lastExecuteTime; +b6kU{
} '9#h^.
public void run(){ 5$p7y:
long now = System.currentTimeMillis(); NHq*&xy
if ((now - lastExecuteTime) > executeSep) { 5qx$=6PT
//System.out.print("lastExecuteTime:"+lastExecuteTime); 5Rec~&v
//System.out.print(" now:"+now+"\n"); Sej\Gt
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); E;C=V2#>[
lastExecuteTime=now; /J0ctJ2k
executeUpdate(); +idp1SJ4
} 6 N.+
else{ ti^msC8e
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); \LZVazXD
} ^zVBS7`J
} .|9o`mF7
} 7BDoF!kCx
//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 L;s,x V
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类写好了,下面是在JSP中如下调用。 vx8-~Oq{|;
.ITR3]$
<% iH""dtO
CountBean cb=new CountBean(); BSib/)p
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 0"to]=
CountCache.add(cb); fA>FU/r
out.print(CountCache.list.size()+"<br>"); #'jd.'>
CountControl c=new CountControl(); KQ(7% W
c.run(); 1P+Te,I
out.print(CountCache.list.size()+"<br>"); ' Zmslijf
%>