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: rWJKK
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CountBean.java LtK,_j
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/* _SQ]\Z
* CountData.java vSk1/
* TtgsM}Fm
* Created on 2007年1月1日, 下午4:44 * K0aR!
* ;p:CrFv
* To change this template, choose Tools | Options and locate the template under :* J!
* the Source Creation and Management node. Right-click the template and choose gY_AO1
* Open. You can then make changes to the template in the Source Editor. `(~oZbErM
*/ vh^?M#\
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package com.tot.count; ;Ehv1{;
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/** 4"Mq]_D
* 8>(/:u_x
* @author dRBWJ/ 1T
*/ au/5`
public class CountBean { 'NDr$Qc3
private String countType; qrcir-+
int countId; U+VyH4"
/** Creates a new instance of CountData */ O66b^*=N}x
public CountBean() {} l^rQo_alk
public void setCountType(String countTypes){ m|PJwd6
this.countType=countTypes; `Yyi;!+0
} iT</
public void setCountId(int countIds){ KuMH,rXF
this.countId=countIds; ,m5tO
} iO}KERfU
public String getCountType(){ LVJn2t^
return countType; i.e4<|{
} ra^"Vr
public int getCountId(){ >&Y\g?Z6G
return countId; eqqnR.0
} :13u{5:th
} </_.+c [
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CountCache.java lDZ~
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/* t_ \&LMD
* CountCache.java X5=I{eY}
* ^t,haO4
* Created on 2007年1月1日, 下午5:01 [iC]Wh%
* [x
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* To change this template, choose Tools | Options and locate the template under Myh?=:1~(c
* the Source Creation and Management node. Right-click the template and choose )g`~,3G
* Open. You can then make changes to the template in the Source Editor. Ij:yTu
*/ @GF3g=
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package com.tot.count; 40 zO4
import java.util.*; i_av_I-
/** $5>m\wrl
* m1M6N`f
* @author SA?1*dw)
*/ z<8VJZd
public class CountCache { T/jxsIt3
public static LinkedList list=new LinkedList(); T[2<_ nn=
/** Creates a new instance of CountCache */ hbs /S
public CountCache() {} nY,LQ0r
public static void add(CountBean cb){ \+k~p:d_8
if(cb!=null){ TNF
list.add(cb); :)%cL8Nz]$
} x\YVB',h
} uFFC.w
} dcfwUjp[
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CountControl.java JY3!jtv
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/* nI8zT0o
* CountThread.java A:5P
* mB%m<Zo\U
* Created on 2007年1月1日, 下午4:57 bb$1zSA
* /buj(/q^#
* To change this template, choose Tools | Options and locate the template under @2TfW]6
* the Source Creation and Management node. Right-click the template and choose <eZrb6a'
* Open. You can then make changes to the template in the Source Editor. e1hf{:&/G@
*/ {~#d_!(
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package com.tot.count; Uh'W d_?
import tot.db.DBUtils; \\35}
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import java.sql.*; k7M{+X6[
/** }6*JX\'q
* c)c_Qv
* @author m/`L3@7Tt
*/ <"av /`;
public class CountControl{ S(lqj6aa}
private static long lastExecuteTime=0;//上次更新时间 {ea*dX872:
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 JvS
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/** Creates a new instance of CountThread */ Pd~z%VoO
public CountControl() {}
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public synchronized void executeUpdate(){ v+CW([zAx#
Connection conn=null; milQxSpj
PreparedStatement ps=null; 6` 3kNk;
try{ %h
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conn = DBUtils.getConnection(); SRrp=>w?
conn.setAutoCommit(false); m~F ~9&
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); !"'@c
for(int i=0;i<CountCache.list.size();i++){ )4H0Bz2G
CountBean cb=(CountBean)CountCache.list.getFirst(); tR_DN
CountCache.list.removeFirst(); sR| /s3;
ps.setInt(1, cb.getCountId()); ;XXEvRk
ps.executeUpdate();⑴ Z 2lX^z
//ps.addBatch();⑵ 1"T&B0G3l
} N5b&tJbM0
//int [] counts = ps.executeBatch();⑶ ?S.LGc
conn.commit(); zoj
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}catch(Exception e){ >uE<-klv
e.printStackTrace(); k0xm-
} finally{ $B OpjDV8
try{ ][~rk?YY
if(ps!=null) { GD!!xt
ps.clearParameters(); )7Oj
ps.close(); " pL5j
ps=null; 9W j9=
} #:Ukv?
}catch(SQLException e){} !@>:k3DC&
DBUtils.closeConnection(conn); T? ,Q=.
} \]Rmq_O
} EDg; s-T=
public long getLast(){ !ce,^z&5
return lastExecuteTime; Qk&6Z%
} _;-b ZH
public void run(){ +@<@x4yt
long now = System.currentTimeMillis(); t<cWMx5ra
if ((now - lastExecuteTime) > executeSep) { IOl0=+p
//System.out.print("lastExecuteTime:"+lastExecuteTime); l#]+I YD
//System.out.print(" now:"+now+"\n"); 3GZrVhU?m
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ^{-Z3Yxd
lastExecuteTime=now; 2-:` lrVd
executeUpdate(); +^a@U^V
} %3q7i`AZ
else{ QtOT'<2t]
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ^_o:Ddz?l"
} dkZ[~hEQG-
} ~%sNPKjA
} Rz33_ qA
//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 W}k)5<C4v
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类写好了,下面是在JSP中如下调用。 X{qa|6S,F
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<% ;(LC{jY
CountBean cb=new CountBean(); "=0JYh)%_
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); L(BL_
CountCache.add(cb); S?Uvt?
out.print(CountCache.list.size()+"<br>"); hy@e(k|S]U
CountControl c=new CountControl(); $"Nqto~
c.run(); ~uJO6C6A
out.print(CountCache.list.size()+"<br>"); wE_#b\$=b
%>