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: 2`V0k.$?p
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CountBean.java zq$0 ?vGd
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/* ;e2D}
* CountData.java .8|"@
* y
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* Created on 2007年1月1日, 下午4:44 i"^ yy+
* uesIkJ^Q[
* To change this template, choose Tools | Options and locate the template under j3R}]F'C*
* the Source Creation and Management node. Right-click the template and choose f?QP(+M5.
* Open. You can then make changes to the template in the Source Editor. dA#'HMh@
*/ Nc^:v/(P
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package com.tot.count; Lu71Qdu09
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/** !Ks<%;
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*
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* @author QNZ#SG8
*/ (F*y27_u
public class CountBean {
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private String countType; /W{^hVkvC
int countId; MMQ\V(C
/** Creates a new instance of CountData */ TQpR'
public CountBean() {} F\<{:wu
public void setCountType(String countTypes){ ,9buI='
this.countType=countTypes; )'/xNR
} h.xtkD)Y~
public void setCountId(int countIds){ cf\GC2+"^$
this.countId=countIds; rLp0)Go
} ~kI$8oAry
public String getCountType(){ K;R!>p}t
return countType; Xk :_aJ
} `{ \)Wuw
public int getCountId(){ DU@SXb
return countId; 'qoaMJxN`
} bW GMgC
} Rf!$n7& \
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CountCache.java 3[R[`l]v?
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/* p3IhK>
* CountCache.java qjN*oM,
* 0J.]`kR
* Created on 2007年1月1日, 下午5:01 |-]'~@~
* k4JTc2b
* To change this template, choose Tools | Options and locate the template under ^HWa owy=
* the Source Creation and Management node. Right-click the template and choose .p78
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* Open. You can then make changes to the template in the Source Editor. NC"X{$o2
*/ ,H]S-uK~
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package com.tot.count; F ^)(
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import java.util.*; -{p~sRc&
/** cZ,}1?!
* Cv<
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* @author `Js"*[z
*/ b}ODc]3
public class CountCache { (I#3![q
public static LinkedList list=new LinkedList(); R E9`T
/** Creates a new instance of CountCache */ %d0BQ|
public CountCache() {} Ee{Y1W
public static void add(CountBean cb){ .bNG:y>
if(cb!=null){ we33GMxHl`
list.add(cb); u"U7aYGkY
} wd2z=^S~
} T=[/x=
} u y13SkW
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CountControl.java g7v(g?
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/* XrGP]k6.^
* CountThread.java 2zkOs:
* 15kkf~Z<t
* Created on 2007年1月1日, 下午4:57 Pu,2a+0N
* 3
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* To change this template, choose Tools | Options and locate the template under tf>"fU\P
* the Source Creation and Management node. Right-click the template and choose I(qFIV+HR
* Open. You can then make changes to the template in the Source Editor. "8\2w]"
*/ Lr*\LP6jx3
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package com.tot.count; }k@SmO8
import tot.db.DBUtils; Eg_ram`\R
import java.sql.*; iE^=Vf;
/** $AdBX}{
* |u#7@&N1
* @author d_Z?i#r0l
*/ =F46v{la
public class CountControl{ G54`{V4&s
private static long lastExecuteTime=0;//上次更新时间 |+Tq[5&R
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ?:i,%]zxC
/** Creates a new instance of CountThread */ CTQJ=R"
public CountControl() {} ~L"?C
public synchronized void executeUpdate(){
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Connection conn=null; 5p~hUP]tT
PreparedStatement ps=null; SnY{|
try{ tcJN`N
conn = DBUtils.getConnection(); D/Py?<n-B
conn.setAutoCommit(false); 1;~|[C
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); HnKXO
for(int i=0;i<CountCache.list.size();i++){ QVkrhwp
CountBean cb=(CountBean)CountCache.list.getFirst();
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CountCache.list.removeFirst(); sY&Z/Y
ps.setInt(1, cb.getCountId()); G
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ps.executeUpdate();⑴ 9<5S!?JL
//ps.addBatch();⑵ j7J'd?l
} nPUD6<bF
//int [] counts = ps.executeBatch();⑶ +77B656
conn.commit(); b[ ~-b
}catch(Exception e){ rXq{WS`
e.printStackTrace(); EvF[h:C2
} finally{ )Cd.1X8
try{ ur[^/lxx0
if(ps!=null) { Yzw[.(jc}
ps.clearParameters(); JgBC:t^\pV
ps.close(); EKEJ9Y+47H
ps=null; V+t's*9o3
} l\ VrD2j8
}catch(SQLException e){} $t0JfDd6Ky
DBUtils.closeConnection(conn); r'MA$PiS'
} +tJ 7ZR%
} WF<3
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public long getLast(){ 22 feYm|
return lastExecuteTime; x7/";L>
} =X7_!vSv
public void run(){ $ByP 9=|
long now = System.currentTimeMillis(); xL"O~jTS
if ((now - lastExecuteTime) > executeSep) { t$rla_rbY
//System.out.print("lastExecuteTime:"+lastExecuteTime); "6Z(0 iu:{
//System.out.print(" now:"+now+"\n"); 664D5f#EJ
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); /|isRh|
lastExecuteTime=now; 7 4]qz,
executeUpdate(); s%1ZraMvJ
} `Ay:;I
else{ -\2hSIXj
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ~JO.h$1C
} >~_)2_j
} eg24.W9c
} 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 \J;_%-Z
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类写好了,下面是在JSP中如下调用。 DKF
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<% t8`wO+4@
CountBean cb=new CountBean(); wOsg,p;\'
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); I{=Yuc
CountCache.add(cb); PlCj<b1D:
out.print(CountCache.list.size()+"<br>"); gyuBmY
CountControl c=new CountControl(); jwP5pu
c.run(); 3cF8DNh
out.print(CountCache.list.size()+"<br>"); w/*m_O\!
%>