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: {t('`z
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CountBean.java uLt31G()
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/* r
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* CountData.java ]OC?g2&6
* E/C3t2@-
* Created on 2007年1月1日, 下午4:44 \"+}-!wr
* 8?hj}}H
* To change this template, choose Tools | Options and locate the template under YG#{/;^nm)
* the Source Creation and Management node. Right-click the template and choose Mw6
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* Open. You can then make changes to the template in the Source Editor. M1K[6V!
*/ =BeJ.8$@VC
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package com.tot.count; Fw%S%*B8g
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/** [tJp^?6*
* 6^z):d#u
* @author xv_Z$&9e>l
*/ ]ia{N
public class CountBean { io7Zv*&T0
private String countType;
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int countId; YcM0A~<
/** Creates a new instance of CountData */ m3`J9f,c/
public CountBean() {} y6>fK@K~
public void setCountType(String countTypes){ ~@D{&7@
this.countType=countTypes; #ahe@|E'Y
} z+j3j2
public void setCountId(int countIds){ M{X; H'2
this.countId=countIds; 4` :Eiik&p
} #D%l;Ae
public String getCountType(){ n7bML?f'
return countType; "]yfx@)_
} IG4`f~k^
public int getCountId(){ wkD"EuW(
return countId; I:] Pd
} hhJs$c(
} rKr\Qy+q
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CountCache.java s<8|_Dt
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/* -'j|U[&N\
* CountCache.java *,Sa*-7(
* `m-7L
* Created on 2007年1月1日, 下午5:01 )fbYP@9>a
* ?b?YiK&yz
* To change this template, choose Tools | Options and locate the template under 9@YhAj
* the Source Creation and Management node. Right-click the template and choose xepp."O
* Open. You can then make changes to the template in the Source Editor. ,veI'WHMB
*/ -K0!wrKC
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package com.tot.count; }J_#N.y
import java.util.*; Y58et9gRO
/** f}Uf*Bp
* v.>95|8
* @author [9~6, ;6
*/ nOU.=N
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public class CountCache { WCg&*
public static LinkedList list=new LinkedList(); dz)(~@tgz
/** Creates a new instance of CountCache */ #$,b )Uy
public CountCache() {} =m?x5G^
public static void add(CountBean cb){ 9*? i89T
if(cb!=null){ ?Nl@K/
list.add(cb); 4l_~-Peh
} D3C3_
@*
} R(#ZaFuo[
} /Hyi/D{ W
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CountControl.java {0\9HI@
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/* uVzvUz{b
* CountThread.java 2E@y0[C?
* ,xy$h }g
* Created on 2007年1月1日, 下午4:57 eJ60@N\A
* `'b2 z=j
* To change this template, choose Tools | Options and locate the template under .-cx9&
* the Source Creation and Management node. Right-click the template and choose D8)6yPwE
* Open. You can then make changes to the template in the Source Editor. R-1C#R[
*/ +y|Q7+
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package com.tot.count; 'E4}++\
import tot.db.DBUtils; e^or qw/I
import java.sql.*; oN=>U"<\1
/** bA/'IF+
* /(DnMHn\
* @author 6Vu)
*/ /vw$3,*z
public class CountControl{ e9rgJJ
private static long lastExecuteTime=0;//上次更新时间 }k_'a^;C1
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 !5>PZ{J
/** Creates a new instance of CountThread */ {,e-;2q
public CountControl() {} G@o\D-$
public synchronized void executeUpdate(){ $)VnHr `hy
Connection conn=null; uS5ADh
PreparedStatement ps=null; WL}XD
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try{ B<&g
conn = DBUtils.getConnection(); `5 MK(K
:
conn.setAutoCommit(false); 6sNw#pqh
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); GyQvodqD
for(int i=0;i<CountCache.list.size();i++){ Qv1cf
CountBean cb=(CountBean)CountCache.list.getFirst(); ria.MCe\!
CountCache.list.removeFirst(); h|OWtf4
ps.setInt(1, cb.getCountId()); `"y:/F"{
ps.executeUpdate();⑴ M^.>UZKyl
//ps.addBatch();⑵ {EyWSf"
} ?I;PJj
//int [] counts = ps.executeBatch();⑶ mIv}%hD
conn.commit(); wfQImCZ>l
}catch(Exception e){ y`8jz,&.
e.printStackTrace(); mtVoA8(6
} finally{ #bGYd}BfD
try{ WUGFo$xA
if(ps!=null) { 8Bx58$xRq
ps.clearParameters(); b-YmS=*
ps.close(); gm7 [m}
ps=null; Zo}vV 2
} \-r"%@OkW
}catch(SQLException e){} R#HX}[Hb
DBUtils.closeConnection(conn); |F&02f!]@
} pSodTG$E
} 'm.+ S8
public long getLast(){ Gk:k
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return lastExecuteTime; 3|4<SMm
} ?7A>|p?"
public void run(){ D|IS@gWa
long now = System.currentTimeMillis(); '8;'V%[+
if ((now - lastExecuteTime) > executeSep) { Pdk#"H-j
//System.out.print("lastExecuteTime:"+lastExecuteTime); oH(=T/{
//System.out.print(" now:"+now+"\n"); P
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); }gKJ~9Jg
lastExecuteTime=now; O[ F
executeUpdate(); /&zlC{:G92
} 1Hs'YzvY
else{ TVAa/_y2`
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Fmzkbt~oe
} XUTsW,WC
} o&>aYlXd
} Hh*
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//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 UHBMl>~z
#q6#nfi"
类写好了,下面是在JSP中如下调用。 >O~
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<% hp}JKj@
CountBean cb=new CountBean(); ku
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); =4gPoS
CountCache.add(cb); |2Uw8M7.E
out.print(CountCache.list.size()+"<br>"); Uz%2{HB@{
CountControl c=new CountControl(); _=HNcpDA;0
c.run(); Gyb|{G_
out.print(CountCache.list.size()+"<br>"); X~Hm.qIR
%>