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: _
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CountBean.java [E~,> Q
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/* x0A%kp&w
* CountData.java cNr][AzU@
* <Ihed|
* Created on 2007年1月1日, 下午4:44 mjl!Nth:<
* ?SO F
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* To change this template, choose Tools | Options and locate the template under m=iov2K>
* the Source Creation and Management node. Right-click the template and choose Eb[H3v48,
* Open. You can then make changes to the template in the Source Editor. T7,Gf({
*/ v~2XGm
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package com.tot.count; Px7g\[]
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/** _d0-%B
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* dezL{:Ya
* @author Vc52s+7=8
*/ b)hOzx
public class CountBean { 3zA=q[C
private String countType; y]pN=<*h5
int countId; ?> M oV5
/** Creates a new instance of CountData */ Q xF8=p
public CountBean() {} S[hJ{0V
public void setCountType(String countTypes){ wz0$g4
this.countType=countTypes; fpK0MS]=b
} g.Caapy
public void setCountId(int countIds){ B
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this.countId=countIds; Z:Y.":[
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} h
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public String getCountType(){ &8_f'+i0
return countType; d+m6-4[_k
} C|d!'"p
public int getCountId(){ (_&V9vat=
return countId; (-'0g@0UA
} 1[/$ZYk:
} d[RWkk5
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CountCache.java :YJ7J4
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/* &X]=Qpl
* CountCache.java ,4>WLJDo
* /Xu;/MMpd3
* Created on 2007年1月1日, 下午5:01 Z:o
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*
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* To change this template, choose Tools | Options and locate the template under 2.Eu+*UC
* the Source Creation and Management node. Right-click the template and choose kJvy<(iG
* Open. You can then make changes to the template in the Source Editor. ngkeJ)M0$
*/ `m@]
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package com.tot.count; ,'1Olu{v[s
import java.util.*; a._^E/EV
/** %$Jqt
* W]!@Zlal
* @author l\sS?
*/ 2 -p
public class CountCache { jgo<#AJ/E
public static LinkedList list=new LinkedList(); f.$aFOn
/** Creates a new instance of CountCache */ ^!o1l-Y^gr
public CountCache() {} =8$0$d
public static void add(CountBean cb){ kHJDX;
if(cb!=null){ PK2Rj%
list.add(cb); pRiH,:\
} Xv-1PY':pA
} 4l%?mvA^m
} v`_i1h9p{
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CountControl.java iFwyh`Bcg
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/* #GY&$8.u*
* CountThread.java ezg^5o;
* p'Y&Z?8
* Created on 2007年1月1日, 下午4:57 '?`@7Eol
* FD
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* To change this template, choose Tools | Options and locate the template under E*r
* the Source Creation and Management node. Right-click the template and choose qr'x0r|<>
* Open. You can then make changes to the template in the Source Editor. \C+*loLs
*/ aJy>
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package com.tot.count; <w UD
import tot.db.DBUtils;
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import java.sql.*; HeT6Dv
/** /jjW/lr
* Ere?d~8
* @author ]{Mci]H6T
*/ <uBhi4
public class CountControl{ 2|0Qk&
private static long lastExecuteTime=0;//上次更新时间 G. -h=DT]
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 q:2aPfo&
/** Creates a new instance of CountThread */ *;OJ~zT
public CountControl() {} [xZ/ZWb/
public synchronized void executeUpdate(){ C-a*EG
Connection conn=null; aDN6MZM
PreparedStatement ps=null; 2,8/Cb
try{ *l> [`U+
conn = DBUtils.getConnection(); IDGQIg
conn.setAutoCommit(false); |5}rX!wS4
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ~),;QQ,
for(int i=0;i<CountCache.list.size();i++){ j.=UI-&m
CountBean cb=(CountBean)CountCache.list.getFirst(); |<j,Tr1[
CountCache.list.removeFirst(); !"`@sd~
ps.setInt(1, cb.getCountId()); Q
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ps.executeUpdate();⑴ [l8V<*x%S9
//ps.addBatch();⑵ %k3NT~
} fCt^FU
//int [] counts = ps.executeBatch();⑶ /RJ6nmN@}
conn.commit(); DD12pL{QA
}catch(Exception e){ zz(!t eBC
e.printStackTrace(); J{Y6fHFi
} finally{ ^eTDD
try{ u%6Irdx
if(ps!=null) { Z/89&Uy`h
ps.clearParameters(); lj
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ps.close(); NCowt|#t
ps=null; YVQ_tCC_!
} la
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}catch(SQLException e){} YBYB OH
DBUtils.closeConnection(conn); *3A3>Rwu
} dWsT Jyx~
} E;6Y? vJ
public long getLast(){ ~-XOvKJb
return lastExecuteTime; YMc8Q\*B
} 4zo4H~@gk
public void run(){ ~q0I7M
long now = System.currentTimeMillis(); [,OJX
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if ((now - lastExecuteTime) > executeSep) { Xt</ -`
//System.out.print("lastExecuteTime:"+lastExecuteTime); iGG6Myp-
//System.out.print(" now:"+now+"\n"); _u:>1]
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Qqd6.F
lastExecuteTime=now; `3f_d}b
executeUpdate(); -Z:]<;qU
} /6+1{p
else{ !cq=)xR
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); B#HV20\?v
} +V)qep"
} }1U#Ve,=_
} P'a0CE%
//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 qn2o[x
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类写好了,下面是在JSP中如下调用。 L*zbike
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<% (H&@u9K?a?
CountBean cb=new CountBean(); qSFc=Wwc
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); vVI6m{zYV
CountCache.add(cb); rPRrx-A
out.print(CountCache.list.size()+"<br>"); 38[)[{G)Hv
CountControl c=new CountControl(); jP1$qhp
c.run(); bjPka{PBj
out.print(CountCache.list.size()+"<br>"); K^"w]ii=
%>