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: m9h<)D '>
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CountBean.java (~Z&U
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/* BMq> Cj+
* CountData.java CLND[gc
* 0H rvr
* Created on 2007年1月1日, 下午4:44 N_G&nw
* "=2\kZ
* To change this template, choose Tools | Options and locate the template under LYAGpcG
* the Source Creation and Management node. Right-click the template and choose 2fdN@iruB
* Open. You can then make changes to the template in the Source Editor. X$<pt,}%
*/ aj|3(2;Kp
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package com.tot.count; 9z?c0W5x
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/** a|TUH+|
* E2l"e?AN~
* @author e'~Qe_
*/ v1u~[c=|^
public class CountBean { [`|t( E'
private String countType; -Tvnd,
int countId; Y"ta`+VJ
/** Creates a new instance of CountData */ _9-;35D_
public CountBean() {} $Ptl&0MN%
public void setCountType(String countTypes){ ?taC
!{
this.countType=countTypes; 8-gl$h
} &pY$\
public void setCountId(int countIds){ eG+$~\%Fub
this.countId=countIds; #Br`;hL<T
} Q?hf2iw
public String getCountType(){ ((?"2 }1r
return countType; u;%~P 9O
} !C4)P3k
public int getCountId(){ l`75BR
return countId; 8\nka5
} J<NpA(@^
} ZC$u8$+P
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CountCache.java alxIc.[
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/* Rhlm
* CountCache.java R,7.o4Wt
* <bn|ni|c"
* Created on 2007年1月1日, 下午5:01 'xEomo#
* lX.1B&T9Lr
* To change this template, choose Tools | Options and locate the template under +-x+c:
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* the Source Creation and Management node. Right-click the template and choose {OQ)Np!
* Open. You can then make changes to the template in the Source Editor. rD6NUS
*/ \7UeV:3Ojn
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package com.tot.count; ("f~gz<<
import java.util.*; 3Zz_wr6
/** @6[aLF]F
* dtQ3iuV %
* @author U_9|ED:
*/ dXWG`G_
public class CountCache {
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public static LinkedList list=new LinkedList(); SXXO#
/** Creates a new instance of CountCache */ '[[IalQ?
public CountCache() {} yqJ>Z%)hf
public static void add(CountBean cb){ eZL!Z!
if(cb!=null){ rIyIZWkI
list.add(cb); /w5c:BH
} 7wrRIeES
} 3nq4Y'
} o`~,+6]D
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CountControl.java #pD=TMefC
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/* GB*^?Ii
* CountThread.java dphWxB
* Oxi^&f||`
* Created on 2007年1月1日, 下午4:57 25vq#sS]
* ip|l3m$ Mi
* To change this template, choose Tools | Options and locate the template under vN6)Szim
* the Source Creation and Management node. Right-click the template and choose 7&dF=/:X@
* Open. You can then make changes to the template in the Source Editor. [MAvU?;
*/ KrTlzbw&p\
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package com.tot.count; Fe2iG-ec
import tot.db.DBUtils; <UW-fI)X
import java.sql.*; %u?A>$Jn
/** M\08 7k
* 0b=00./o
* @author }.A
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*/ BI>r'
public class CountControl{ _k)EqPYu@
private static long lastExecuteTime=0;//上次更新时间 [xDn=)`{V
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 LD;!
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/** Creates a new instance of CountThread */ q' t"
public CountControl() {} @ +>>TGC
public synchronized void executeUpdate(){ tv9 R$-cJ
Connection conn=null; ;3=RM\
PreparedStatement ps=null; 7$kTeKiP
try{ w\>@>*E>
conn = DBUtils.getConnection(); S8e ?-rC
conn.setAutoCommit(false); ?KFj=Yo
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); .UUT@
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for(int i=0;i<CountCache.list.size();i++){ _dVA^m
CountBean cb=(CountBean)CountCache.list.getFirst(); aslb^
CountCache.list.removeFirst(); *)T7DN8
ps.setInt(1, cb.getCountId()); ;C5
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ps.executeUpdate();⑴ F,xFeq$/{
//ps.addBatch();⑵ 8J0#lu
} E7U.>8C
//int [] counts = ps.executeBatch();⑶ 9!Bz)dJ3
conn.commit(); P7qzZ
}catch(Exception e){ {G-y7y+E
e.printStackTrace(); :w9s bW
} finally{ %Xl(wvd
try{ $btk48a 7
if(ps!=null) { V}/AQe2m&
ps.clearParameters(); B|kIiL63
D
ps.close(); !F)BTB7{<
ps=null; CuYSvW
} zRA,Yi4;+
}catch(SQLException e){} oazy%n(KZ
DBUtils.closeConnection(conn); q}p
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} Y-P?t+l
} g-2(W
public long getLast(){ A~wVY
return lastExecuteTime; 10..<v7
} B"Ttr+
public void run(){ e8hwXz
long now = System.currentTimeMillis(); ;<s0~B#9}
if ((now - lastExecuteTime) > executeSep) { TE@bV9a
//System.out.print("lastExecuteTime:"+lastExecuteTime); }N#hg>;
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//System.out.print(" now:"+now+"\n"); N'M+Z=!
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); IUwMIHq&sW
lastExecuteTime=now; Ehg(xK
executeUpdate(); f5vsxP)Y[
} w*IDL0#
else{ &&|c-mD+*
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); LVNJlRK
} >?^_JEC6
} c~n:xblv
} u\ }"l2 r
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 =o,6iJ^?$m
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类写好了,下面是在JSP中如下调用。 %gV~e@|
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<% njBK {
CountBean cb=new CountBean(); Q1u/QA:z7
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); S,^)\=v
CountCache.add(cb); 6e At`L[K.
out.print(CountCache.list.size()+"<br>"); P~ODd(
CountControl c=new CountControl(); 7G
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c.run(); yq\p%z$:
out.print(CountCache.list.size()+"<br>"); (b;*8
%>