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: -0`hJ_(
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CountBean.java A-io-P7qyj
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/* r Lh
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* CountData.java (Gn[T1p?
* 7q 2YsI
* Created on 2007年1月1日, 下午4:44 .T|NB8 rS
* zT% kx:Fk
* To change this template, choose Tools | Options and locate the template under @\y7
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* the Source Creation and Management node. Right-click the template and choose P1QJ'eC;T
* Open. You can then make changes to the template in the Source Editor. {dwV-qz
*/ q T].,?
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package com.tot.count; Lk9>7xY
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/** RtL<hD
* ^ztf:'l@C
* @author 4.'EEuRw\}
*/ %&XX*&
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public class CountBean { kTz
private String countType; iV5I
int countId; /v{[Z&z
/** Creates a new instance of CountData */ )rj mJ
public CountBean() {} ?N
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public void setCountType(String countTypes){ aK{\8L3]
this.countType=countTypes; qM0MSwvC=
} 76b7-Nj"
public void setCountId(int countIds){ 1Tq$ E[
this.countId=countIds; )9r%% #
} 1Q5<6*QL"
public String getCountType(){ DBUwf1=qj
return countType; mz*z1`\7v\
} k%g xY% 0
public int getCountId(){ )US/bC!M$
return countId; `<zb
} .F2nF8
} {nefS\#{
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CountCache.java =T)2wcXBB
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/* X6 ,9D[Nw
* CountCache.java v8Zgog)V
*
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* Created on 2007年1月1日, 下午5:01 ,NEs{!
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* ugB{2oq i
* To change this template, choose Tools | Options and locate the template under LrMFzd}_O
* the Source Creation and Management node. Right-click the template and choose -y?Z}5-rs
* Open. You can then make changes to the template in the Source Editor. (NdgF+'=
*/ >@U<?wP
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package com.tot.count; k+[KD >;1
import java.util.*; nY9qYFw
/** k~f+L O
* +{%(_<
* @author h50StZ8Yr
*/ nZCpT
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public class CountCache { `M ygDG+u
public static LinkedList list=new LinkedList(); &8_;:
/** Creates a new instance of CountCache */ aT#{t{gkA
public CountCache() {} Db=>7@h3C
public static void add(CountBean cb){ S=,1}
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if(cb!=null){ $ud>Z;X=P
list.add(cb); }+
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}
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} fVUBCu
} 51qIo 4$
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CountControl.java t`T\d\
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/* `^L<db^A
* CountThread.java \>Rwg=Lh
* H?j-=Zka
* Created on 2007年1月1日, 下午4:57 9>3Ltnn0
* U;{,lS2l
* To change this template, choose Tools | Options and locate the template under C;q}3c*L
* the Source Creation and Management node. Right-click the template and choose _(`X .D
* Open. You can then make changes to the template in the Source Editor. mN{ajf)@
*/ d._gH#&v
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package com.tot.count; s}#[*WOc
import tot.db.DBUtils; IS2Ij
import java.sql.*; x}<G!*3
/** V`,[=u?c
* n>:c}QAJH
* @author R}w wC[{
*/ l5';?>!s
public class CountControl{ p@8krOo`
private static long lastExecuteTime=0;//上次更新时间 kgI=0W>
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 pq?[ wp"
/** Creates a new instance of CountThread */ n,jE#Z.D
public CountControl() {} f=_?<I{
public synchronized void executeUpdate(){ IHbo w0'
Connection conn=null; qH%L"J
PreparedStatement ps=null; 5u)^FIBj
try{ {0vbC/?]
conn = DBUtils.getConnection(); V\K
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conn.setAutoCommit(false); }gi1?a59
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); "gN* J)!x
for(int i=0;i<CountCache.list.size();i++){ R%N#G<^R
CountBean cb=(CountBean)CountCache.list.getFirst(); V> a3V'
CountCache.list.removeFirst(); {<}I9D5
ps.setInt(1, cb.getCountId()); CDW(qq-zD
ps.executeUpdate();⑴ ]2\2/~l
//ps.addBatch();⑵ 39T&c85
} 3TiXYH
//int [] counts = ps.executeBatch();⑶ 7
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conn.commit(); b6!Q!:GO&
}catch(Exception e){ J4Z<Yt/
e.printStackTrace(); k[ffs}
} finally{ :qCm71*
try{ x|v[Dxf]
if(ps!=null) { }8V;s-1
ps.clearParameters(); H]i+o6
ps.close(); _UBJPb@=U
ps=null; ^dUfTG9{
} t66f 7AR
}catch(SQLException e){} oa&US_
DBUtils.closeConnection(conn); F0BOhlK
} p#;dLM/EA
} eW"x%|/Q7
public long getLast(){ D;^ZWz0
return lastExecuteTime; vQBY1-S
} b*FU*)<4.
public void run(){ SEQO2`]e:
long now = System.currentTimeMillis(); bm tJU3Rm
if ((now - lastExecuteTime) > executeSep) { GrLM${G
//System.out.print("lastExecuteTime:"+lastExecuteTime); c(Uj'uLc
//System.out.print(" now:"+now+"\n"); U)`3[fo
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); cB|Cy{%
lastExecuteTime=now; Jl}!CE@-
executeUpdate(); |,a%z-l
} LTYuxZ
else{ D)*_{
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); F`;TU"pDf
} g~Nij~/
} _yxe2[TD
} f`u5\!}=!
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 XgiI6-B~
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类写好了,下面是在JSP中如下调用。 ]*g ss'N
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<% !8
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CountBean cb=new CountBean(); K{=r.W
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); [I++>4
CountCache.add(cb); 7dufY
} }
out.print(CountCache.list.size()+"<br>"); f
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CountControl c=new CountControl(); Gh$y#0qr
c.run(); 6"7:44O;G
out.print(CountCache.list.size()+"<br>"); (!_X:+0_
%>