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: k%JwS_F
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CountBean.java aQw?r
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/* "M1[@xog
* CountData.java ^P\(IDJCo
* pT.iQ J|
* Created on 2007年1月1日, 下午4:44 I=|b3-
* fY$M**/,
* To change this template, choose Tools | Options and locate the template under RCo!sZP}
* the Source Creation and Management node. Right-click the template and choose ^q7
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* Open. You can then make changes to the template in the Source Editor. t-i;
*/ i5q
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package com.tot.count; jBarY g
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/** pjWqI6,
* n<uF9N<
* @author !z$.Jcr1
*/ CsJw;]dYI
public class CountBean { OT&J OTk\
private String countType; I|@%|sTW
int countId; 8lg$]
/** Creates a new instance of CountData */ Ao69Qn
public CountBean() {} m?V4r#t
public void setCountType(String countTypes){ "FwbhD0Gb
this.countType=countTypes; c-(,%0G0
} 2I*
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public void setCountId(int countIds){ Oca_1dlx
this.countId=countIds; #qtAFIm'
} Lo5itW
public String getCountType(){ D .oX>L#:
return countType; tXV9+AJ
} aqSHo2]DX9
public int getCountId(){ B\G?dmo
return countId; ;!v2kVuS]
} ]Nz~4ebB
} $e)d!m.
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CountCache.java ^2rNty,nH
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/* AKk6kI8F
* CountCache.java }(4U7Ac
* SV0E7qX
* Created on 2007年1月1日, 下午5:01 Ne!F
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* OXd617
* To change this template, choose Tools | Options and locate the template under '/trM %<
* the Source Creation and Management node. Right-click the template and choose FAkjFgUJp
* Open. You can then make changes to the template in the Source Editor. =ZR9zL=h
*/ {EE/3e@
* $~H=4t
package com.tot.count; +P:xB0Tm
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import java.util.*; /Ut h#s:
/** #; CC"
* kv{uf$X*ve
* @author bw\fKZ
*/ ?f<JwF<
public class CountCache { ^ ]02)cK
public static LinkedList list=new LinkedList(); ofH=h
/** Creates a new instance of CountCache */ <ZGEmQ
public CountCache() {} e=ZwhRP
public static void add(CountBean cb){ #-*7<wN
if(cb!=null){ D;VQoO
list.add(cb); &.J8O+
} nm5zX,
} $8zsqd 4?
} })RT2zw}
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CountControl.java hqrI%%
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/
/* IA_>x9 (~
* CountThread.java uTgBnv(Y*
* ]k~Vh[[
* Created on 2007年1月1日, 下午4:57 U
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* FYq]-k{\
* To change this template, choose Tools | Options and locate the template under l}odW
* the Source Creation and Management node. Right-click the template and choose ;sJUTp5\h
* Open. You can then make changes to the template in the Source Editor. /^ *GoB
*/ -wv5c
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package com.tot.count; rw_T&>!
import tot.db.DBUtils; /xf4*zr
import java.sql.*; eLE9-K+
/** YF/@]6j
* R-nC+)^
* @author pgT XyAP{
*/ 0w^\sf%s
public class CountControl{ zWvG];fsN
private static long lastExecuteTime=0;//上次更新时间 $jMU|{
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 'A@[a_
/** Creates a new instance of CountThread */ /LMb~Hy,
public CountControl() {} HRS|VC$tz
public synchronized void executeUpdate(){ dv3+x\`9
Connection conn=null; L-ans2?
PreparedStatement ps=null; nsR^TD;
try{ #:Z"V8n'
conn = DBUtils.getConnection(); +<&\*VR
conn.setAutoCommit(false); fq-$u;~h
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Kp,}7%hDw!
for(int i=0;i<CountCache.list.size();i++){ 86d*
CountBean cb=(CountBean)CountCache.list.getFirst(); ,Nl]rmI
CountCache.list.removeFirst(); dLOUL9hf
ps.setInt(1, cb.getCountId()); ?3
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ps.executeUpdate();⑴ +o&E)S}wP
//ps.addBatch();⑵ <()xO(
} bh=d'9B@&J
//int [] counts = ps.executeBatch();⑶ YbZ<=ZzO4
conn.commit(); m(JFlO
}catch(Exception e){ 6S?a57;&W
e.printStackTrace(); U!m-{7s$
} finally{ E\!:MCL
try{ TnET1$@qr*
if(ps!=null) { -eAo3
ps.clearParameters(); lh`inAt)"
ps.close(); !v\m%t|.
ps=null; 5xW)nEV
} e
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}catch(SQLException e){} sQW$P9s
c
DBUtils.closeConnection(conn); cn ,zUG!-h
} ]7kq@o/7
} L;.6j*E*
public long getLast(){ #r 1
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return lastExecuteTime; 5n;|K]UW
} cqeId&Cg
public void run(){ +T[3wL~
long now = System.currentTimeMillis(); [;dWFG"f
if ((now - lastExecuteTime) > executeSep) { (\FjbY9&
//System.out.print("lastExecuteTime:"+lastExecuteTime); xD#PM |I
//System.out.print(" now:"+now+"\n"); ,
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); `xe[\Z2
lastExecuteTime=now; IDBhhv3ak
executeUpdate(); `9Ngax=_
} r5[om$|*
else{ _J&u{
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); !$h%$se
} h./cs'&
} !Dkz6B*
} [$?S9)Xd
//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 3hR7 ./
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类写好了,下面是在JSP中如下调用。 Jf`;F :
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<% tZ>>aiI3
CountBean cb=new CountBean(); ` 2|~Z
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 8s8q`_.)(
CountCache.add(cb); FVG|5'V^
out.print(CountCache.list.size()+"<br>"); P,h@F+OZN
CountControl c=new CountControl(); Fhn883
c.run(); 'DsfKR^s
out.print(CountCache.list.size()+"<br>"); 9 N=KU
%>