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: $X*mdji
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CountBean.java 8tLHr @%%
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/* "PMQyzl
* CountData.java +t9 8@
* DkgUvn/S
* Created on 2007年1月1日, 下午4:44 mEFw|M{
* Yd:Q`#7A
* To change this template, choose Tools | Options and locate the template under f1mHN7hxW
* the Source Creation and Management node. Right-click the template and choose !}y1CA
* Open. You can then make changes to the template in the Source Editor. hSB?@I4s<\
*/ $Pxb1E
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package com.tot.count; t9FDU
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/** )RN<GW'
* ;QBh;jg4
* @author j!\dn!Xwt
*/ 5 L/x-i
public class CountBean { W|MWXs5'1*
private String countType; @o>EBZ7MS
int countId; -v]Qhf&>
/** Creates a new instance of CountData */ )%mg(O8uL
public CountBean() {} g5+7p@'fV
public void setCountType(String countTypes){ S]^`woD
this.countType=countTypes; dAc ?O-~
} 2*[QZ9U[@
public void setCountId(int countIds){ ~i ,"87$[
this.countId=countIds; 0,_b)
} ;o0#(xVz
public String getCountType(){ }7eh F6
return countType; zI^]esX!2_
} qP3q
public int getCountId(){ [dB$U}SEj
return countId; *6Q|}b[qcD
} O0T/#<Cn!
} ~`qEWvPn
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CountCache.java u%3i0BajY
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/* T%$jWndI
* CountCache.java !^w
E/
* x5h~G
* Created on 2007年1月1日, 下午5:01 DkDoA;m
* k?*KnfVh!
* To change this template, choose Tools | Options and locate the template under _ \D"E>oM
* the Source Creation and Management node. Right-click the template and choose `!vUsM .d
* Open. You can then make changes to the template in the Source Editor. |4;UyHh
*/ u.,Q4u|!
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package com.tot.count; Vi?q>:E:
import java.util.*; z.36;yT/
/** kJ{+M] pW
* %Jp|z? [/
* @author vDFGd-S
*/ _{4^|{>Pv
public class CountCache { fBhoGA{=g
public static LinkedList list=new LinkedList(); !m;H@KR{
/** Creates a new instance of CountCache */ :>+\17tx
public CountCache() {} 29&bbfU
public static void add(CountBean cb){ SmhGZ
if(cb!=null){ I9?Ec6a_
list.add(cb); \]uV!)V5B
} pTJX""C
} MHU74//fe
} ;"kaF!
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CountControl.java Z
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/* %Ip*Kq-
* CountThread.java GbI-SbE
* #wY0D_3@1
* Created on 2007年1月1日, 下午4:57 _%/}>L>-`8
* YJ_\Ns+Ow
* To change this template, choose Tools | Options and locate the template under kLj$@E`4
* the Source Creation and Management node. Right-click the template and choose %<0eA`F4
* Open. You can then make changes to the template in the Source Editor. z//VlB
*/ ?'s6Xmd
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package com.tot.count; :o46rBs
import tot.db.DBUtils; V5i*O3a~
import java.sql.*; 1yQejw
/** =LkR!R=
* i/H+xrCK
* @author C0jj(ku&
*/ <\ `$Jx#
public class CountControl{ GZip\S4Y
private static long lastExecuteTime=0;//上次更新时间 A\fb<
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 v{aq`uH
/** Creates a new instance of CountThread */ piy`zc-yu
public CountControl() {} q%Yn;g|_
public synchronized void executeUpdate(){ Djq!P
Connection conn=null; 3^?ZG^V
PreparedStatement ps=null; 30>3 !Xqa
try{ ,m_WR7!$E
conn = DBUtils.getConnection(); ZfrVjUB
conn.setAutoCommit(false); #]P9b@@e
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 83%)/_&
for(int i=0;i<CountCache.list.size();i++){ lf(`SYQnOY
CountBean cb=(CountBean)CountCache.list.getFirst(); !-<p,z
CountCache.list.removeFirst(); /FD5G7ES
ps.setInt(1, cb.getCountId()); t.p~\6Yi
ps.executeUpdate();⑴ 5Xn.CBd]
//ps.addBatch();⑵ lVOu)q@l7g
} @$9'@")
//int [] counts = ps.executeBatch();⑶ F$BbYf2i
conn.commit(); */:uV
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}catch(Exception e){ >-8cU_m7s
e.printStackTrace(); 6;'dUGvH
} finally{ qz?mh4Oh
try{ M(x$xAiD
if(ps!=null) { d.UQW
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ps.clearParameters(); _g%TSumvq<
ps.close(); w| `h[/,
ps=null; js iSg/
} 1#IlWEg
}catch(SQLException e){} SZaS;hhhHu
DBUtils.closeConnection(conn); [S5\#=_4S
} gzoEUp=s
} >zAUW[]C:I
public long getLast(){ 86]p#n_>Fv
return lastExecuteTime; ,XDRO./+T
} Gmwf4>"
public void run(){ *g?Po+ef%
long now = System.currentTimeMillis(); f+8wl!M+6
if ((now - lastExecuteTime) > executeSep) { o1M$.*
//System.out.print("lastExecuteTime:"+lastExecuteTime); n3AaZp[
//System.out.print(" now:"+now+"\n"); (hiyNMC
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); <sK4#!K
lastExecuteTime=now; >leU:7
executeUpdate(); 4=<tWa|@9
} }PTV] q%
else{ `x%'jPP1^
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); WSuww
} fhL,aCS=
}
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} F*"}aP$
//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 &f-Uyr7?
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类写好了,下面是在JSP中如下调用。 AbZKYF
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<% y=?)n\f
CountBean cb=new CountBean(); ;>n,:355L
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); AGLscf.
CountCache.add(cb); i3rH'B-I.
out.print(CountCache.list.size()+"<br>"); eek7=Z
CountControl c=new CountControl(); |{CfWSB7~@
c.run(); th;{V%:LW
out.print(CountCache.list.size()+"<br>"); *98$dQR$
%>