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: "1&C\}.7
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CountBean.java _4owxYSDke
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/* %1@+pf/
* CountData.java GasIOPzK
* d;:+Xd`
* Created on 2007年1月1日, 下午4:44 b0tr)>d
* ;-n+=@]7
* To change this template, choose Tools | Options and locate the template under ~Ub'5M
* the Source Creation and Management node. Right-click the template and choose MIsjTKE
* Open. You can then make changes to the template in the Source Editor.
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*/ 'Wn'BRXq3
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package com.tot.count; Y#=0C*FS
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/** Ev,>_1#Xm
* ^r?ZrbSbz
* @author }Cvf[H1+
*/ 7ykpDl^ @
public class CountBean { Z_zN:BJ8L
private String countType; %u,H2*
int countId; Ovq-rI{
/** Creates a new instance of CountData */ A%-*M 'J
public CountBean() {} z|Q)^
public void setCountType(String countTypes){ }G]6Rip3
this.countType=countTypes; #e}Q|pF
} dAh&Z:86\
public void setCountId(int countIds){ eBFsKOtu
this.countId=countIds; %|*tL7
} sy.FMy+
public String getCountType(){ etMQy6E\
return countType; FMc$?mm
} I%ivY
public int getCountId(){ mp*&{[XoVC
return countId; Q_$aiE
} ]o$aGrZ
} }Y[xj{2$O
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CountCache.java V`fp%7W
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/* |C301ENZ
* CountCache.java =2F;'T\6
* zVKbM3(^
* Created on 2007年1月1日, 下午5:01 _D1Uc|
* 7?9QlUO
* To change this template, choose Tools | Options and locate the template under >gRb.-{ux
* the Source Creation and Management node. Right-click the template and choose zR_ "
* Open. You can then make changes to the template in the Source Editor. s!:'3[7+
*/ $Ypt
/`
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package com.tot.count; n`8BE9h^
import java.util.*; J$F
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/** { 0RwjPYp
* CBN,~wzP*
* @author ,bzE`6
*/ <j,ZAA&5%Y
public class CountCache { _C2iP[YwQ{
public static LinkedList list=new LinkedList(); 2w_[c.
/** Creates a new instance of CountCache */ !'8.qs
public CountCache() {} R}_B\# Q
public static void add(CountBean cb){ Sg
if(cb!=null){ :
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list.add(cb); 8s16yuM
} BpBMFEiP
} ~_6~Fi
} cc- liY"
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CountControl.java ~Ap.#VIc'
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/* Q=9Ce@[
* CountThread.java fUx;_GX?
* ', ~
* Created on 2007年1月1日, 下午4:57 #J~
* bWWZGl9
* To change this template, choose Tools | Options and locate the template under fm]mqO
* the Source Creation and Management node. Right-click the template and choose tAF#kBa\y_
* Open. You can then make changes to the template in the Source Editor. l7 Pn5c
*/ eocq Hwbv
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package com.tot.count; e0;0 X7
import tot.db.DBUtils; GB,f'Afl
import java.sql.*; ;O8'vp
/** yAD-sy +/
* |`eHUtjH
* @author zW#P
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*/ ZZq]I
public class CountControl{ O:%s;p
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private static long lastExecuteTime=0;//上次更新时间 !-rG1VI_S*
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 mO<1&{qMZ
/** Creates a new instance of CountThread */ y/i{6P2`,D
public CountControl() {} nl<TM96
public synchronized void executeUpdate(){ |?A:[C#X
Connection conn=null; X!,huB^i
PreparedStatement ps=null; OD[q
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try{ 3Gi^TXE]
conn = DBUtils.getConnection(); =sZ58xA
conn.setAutoCommit(false); )hG4,0hv&
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); .ni<'
for(int i=0;i<CountCache.list.size();i++){ =EFCd=i
CountBean cb=(CountBean)CountCache.list.getFirst(); v}\4/u
CountCache.list.removeFirst(); _4,/uG|a O
ps.setInt(1, cb.getCountId()); CCDU5l$$
ps.executeUpdate();⑴ #mKF)W
//ps.addBatch();⑵ sbv2*fno5
} OFe-e(c1
//int [] counts = ps.executeBatch();⑶ @*e5(@R
conn.commit(); =$mPReA3v
}catch(Exception e){ EDAtC
e.printStackTrace(); Op()`x
m
} finally{ g'cLc5\
try{ %\"<lyD
if(ps!=null) { Ua hsX
ps.clearParameters(); lT^/8Z<g
ps.close(); -.xiq0
ps=null; Mc,3j~i
} *T6*Nxs0k
}catch(SQLException e){} +~(SeTY
DBUtils.closeConnection(conn); KE[!{O^(a
} C&|K7Zp0v
} jYUN:
public long getLast(){ L:j3
return lastExecuteTime; d!{]CZ"@
} %(&$CmS@
public void run(){ CKI.\o
long now = System.currentTimeMillis(); uM)#T*(
if ((now - lastExecuteTime) > executeSep) { Znw3P|>B
//System.out.print("lastExecuteTime:"+lastExecuteTime); 8+i=u"<
//System.out.print(" now:"+now+"\n"); fHK.q({Qc
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); &R5zt]4d&
lastExecuteTime=now; A=W:}szt]
executeUpdate(); _mWVZ1P
} ]*?lgwE
else{ {x{~%)-
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 7F2 WmMS
} XEegUTs
} ~+ kfb^<-
} 3iM7c.f*/
//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 Vx z`
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类写好了,下面是在JSP中如下调用。 tm&,u*6$W?
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<% 2cEvsvw>
CountBean cb=new CountBean(); 'B:8tv
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); brCXimG&jo
CountCache.add(cb); =kTHfdin&
out.print(CountCache.list.size()+"<br>"); dBw7l}
CountControl c=new CountControl(); /:tzSKq}
c.run(); =MU(!`
out.print(CountCache.list.size()+"<br>"); Jxf>!\:AZu
%>