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: 2t $ j
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CountBean.java SNY~9:;]f
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/* TX#m&vh
* CountData.java P./VmY'
* {3&|tk!*
* Created on 2007年1月1日, 下午4:44 QBR=0(giF
* kI%%i>Y}
* To change this template, choose Tools | Options and locate the template under \>Efd
* the Source Creation and Management node. Right-click the template and choose /lafve~
* Open. You can then make changes to the template in the Source Editor. 7Pa@1']
*/ A&>.74}p
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package com.tot.count; 3"F`ZJ]=
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/** ,^S@EDq
* [TNj;o5J
* @author jM\*A#Jo5
*/ <8,cuX\
public class CountBean { j2 !3rI
private String countType; 1T:Y 0
int countId; 6 PxW8pn
/** Creates a new instance of CountData */ iDf,e Kk$'
public CountBean() {} u :F~K
public void setCountType(String countTypes){ |{,KRO0P
this.countType=countTypes; .; )l
} '?({;/L
public void setCountId(int countIds){ %$TGzK 1
this.countId=countIds; p019)X|vx
} 1Z,[|wJ
public String getCountType(){ ^Idle*+
return countType; NH0qVQ@A
} , lJv
public int getCountId(){ c2K:FdB
return countId; g(#f:"
} `SVmQSwO[
} `)QCn<
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CountCache.java uPniLx\t:
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/* +S=Rn,
* CountCache.java w^]6w\p
* UQ4% Xp
* Created on 2007年1月1日, 下午5:01 hUm'8)OJ
* d[;.r
* To change this template, choose Tools | Options and locate the template under w4fW<ISg
* the Source Creation and Management node. Right-click the template and choose +kFxi2L6
* Open. You can then make changes to the template in the Source Editor. VM0j`bs'K*
*/ gkHNRAL
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package com.tot.count; #]'rz,E<
import java.util.*; D0BI5q
/** 5y?-fT]X
* Q3"}Hl2
* @author CA +uKM^"6
*/ rm}
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public class CountCache { $U/YR&vcw
public static LinkedList list=new LinkedList(); kHqzt g
/** Creates a new instance of CountCache */ %e@#uxm
public CountCache() {} It75R}B
public static void add(CountBean cb){ !\g+8>
if(cb!=null){ Zc?ppO
list.add(cb); ox
;
} 3
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} )Jv[xY~
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CountControl.java {?`al5Sz
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/* B7z -7&TE
* CountThread.java ,()0'h}n
* y1/o^d+@
* Created on 2007年1月1日, 下午4:57 b?eu jxqg
* _A0w[n
* To change this template, choose Tools | Options and locate the template under r$wxk 4%Rz
* the Source Creation and Management node. Right-click the template and choose ~gu3g^<0v
* Open. You can then make changes to the template in the Source Editor. TB;o~>9U
*/ !`7B^RZ
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package com.tot.count; Zo{$
import tot.db.DBUtils; 5#QXR+
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import java.sql.*; 4np qJ1
/** \);4F=h}f
* vip~'
* @author Sv;_HZ
*/ m%PC8bf`S
public class CountControl{ XQ*eP?OS{
private static long lastExecuteTime=0;//上次更新时间 5 B=^v#m
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 P#:?ok
/** Creates a new instance of CountThread */ wRrnniqf8
public CountControl() {} J6jwBo2m
public synchronized void executeUpdate(){ u~)`&1{%
Connection conn=null; "5A&_E }3
PreparedStatement ps=null; Uw4>v:
try{ [ib P%xb
conn = DBUtils.getConnection(); %N#%|2B
conn.setAutoCommit(false); $Q*<96M
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); !|<=ZF2
for(int i=0;i<CountCache.list.size();i++){ O3CFme
CountBean cb=(CountBean)CountCache.list.getFirst(); YA&g$!
CountCache.list.removeFirst(); > 0<)=
ps.setInt(1, cb.getCountId()); CZbYAxNl
ps.executeUpdate();⑴ AL5Vu$V~n}
//ps.addBatch();⑵ z(\4M==2O
} 7w1wr)qSB
//int [] counts = ps.executeBatch();⑶ 0dh=fcb
conn.commit(); 8 B**8yg.
}catch(Exception e){ ?i`l[+G
e.printStackTrace(); L_w+y
} finally{ !s@Rok
try{ ^3hn0DVQ
if(ps!=null) { %e@HZ"V
ps.clearParameters(); |!F5.%PY
ps.close(); [NFNzwUB
ps=null; &)oOeRwi].
} aAy'\T$x.
}catch(SQLException e){} A 8 vbQ
DBUtils.closeConnection(conn); 6&bIXy
} 1xc~`~
} yObuWDA9
public long getLast(){
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return lastExecuteTime; ".dZn6"mI
} :eZh'-c?
public void run(){ xW[ -n
long now = System.currentTimeMillis(); |7#[ (%D!
if ((now - lastExecuteTime) > executeSep) { q{ /3V
//System.out.print("lastExecuteTime:"+lastExecuteTime); [p=*u,-
//System.out.print(" now:"+now+"\n"); )Af~B'OUd
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); e${>#>
lastExecuteTime=now; #Mg]GeDJ{
executeUpdate(); BYKoel
} Ssk}e=]
else{ V
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Qeu\&%C!<
} ?h!i0Rsm
} }za[E>z
} '<0J@^vZ
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 I=;+n-
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类写好了,下面是在JSP中如下调用。 }^(}HBT
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<% #Oha(mRY
CountBean cb=new CountBean(); "k Te2iS
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); "6a8s;
CountCache.add(cb); W(hMft%
out.print(CountCache.list.size()+"<br>"); vLxQ *50v$
CountControl c=new CountControl(); r",]Voibd
c.run(); ,|88r=}
out.print(CountCache.list.size()+"<br>"); Z`&4SH=j
%>