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: spT$}F2n
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CountBean.java M $f6.j
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/* 72 ZoN<c
* CountData.java 2Q 5-.2]
* +U)4V}S)
* Created on 2007年1月1日, 下午4:44 SHT`
* HD'adj_,
* To change this template, choose Tools | Options and locate the template under 9oYE
* the Source Creation and Management node. Right-click the template and choose +ZOKfX
* Open. You can then make changes to the template in the Source Editor. /@B2-.w
*/ c:aW"U
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package com.tot.count; }bSDhMV;
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/** ""A6n{4
* /DjsnU~3
* @author SlG^ H
*/ i+F*vTM2,
public class CountBean { P\WFm
private String countType; W-*HAS
int countId; Mh{244|o[
/** Creates a new instance of CountData */ *d`KD64
public CountBean() {} IXG@$O?y/
public void setCountType(String countTypes){ m/"([Y_
this.countType=countTypes; nRvaCAt^
} uW
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public void setCountId(int countIds){ H32o7]lT
this.countId=countIds; ]&N>F8.L+
} OAD W;fj
public String getCountType(){ \B^NdG5Y
return countType; Y'5(exW
} s/B_
public int getCountId(){ 9)t[YE:U3!
return countId; cK >^8T^
} 8+J>jZ
} J?EDz,
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CountCache.java G$2@N6
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/* Oi zj|'
* CountCache.java \Z,{De%
* XK\3"`kd
* Created on 2007年1月1日, 下午5:01 v K[%cA"
* DVVyWn[
* To change this template, choose Tools | Options and locate the template under [uK{``"
* the Source Creation and Management node. Right-click the template and choose +*Z'oC BJ,
* Open. You can then make changes to the template in the Source Editor. !^ad{#|X
*/ -7]j[{?w
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package com.tot.count; xdm \[s
import java.util.*; %g}d}5s
/** qrYbc~jI7
* nYjrEy)Q
* @author <3x%-m+p4
*/ ]*\MIz{56'
public class CountCache { z6C(?R
public static LinkedList list=new LinkedList(); n jWe^
/** Creates a new instance of CountCache */ < ,*\t
public CountCache() {} KU/r"lMNlU
public static void add(CountBean cb){ 3T F_$bd{
if(cb!=null){ *uhQP47B
list.add(cb); M}x%'=Pox
} Giv,%3'
} GXVx/)H
} #f2k*8"eAF
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CountControl.java *x|%Nua"
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/* 0% rDDB
* CountThread.java II=`=H{
* P_1WJ
* Created on 2007年1月1日, 下午4:57 Z^&G9I#
* UhDQl%&He
* To change this template, choose Tools | Options and locate the template under rF-SvSj}
* the Source Creation and Management node. Right-click the template and choose K=[7<b,:3
* Open. You can then make changes to the template in the Source Editor. cERIj0~
*/ G<$:[ +w
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package com.tot.count; )=[\Yf K
import tot.db.DBUtils; ltNCti{Q
import java.sql.*; l/'GbuECm
/** wf\"&xwh?
*
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* @author NZB*;U~t
*/ N>H@vt~
public class CountControl{ 4^L;]v,|7
private static long lastExecuteTime=0;//上次更新时间 u /F!8#
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 k4K.
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/** Creates a new instance of CountThread */ ?}cmES kX@
public CountControl() {} Vke<; k-
public synchronized void executeUpdate(){ 2 ?t@<M]
Connection conn=null; _`udd)Y2
PreparedStatement ps=null; +;KUL6
try{ VhUWws3E
conn = DBUtils.getConnection(); ##rkyd
conn.setAutoCommit(false); *4U_MM#rX
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); <a6pjx>y
for(int i=0;i<CountCache.list.size();i++){ ]].~/kC^3k
CountBean cb=(CountBean)CountCache.list.getFirst(); }HoCfiE=X
CountCache.list.removeFirst(); M}\h?s
ps.setInt(1, cb.getCountId()); Ss>pNH@c
ps.executeUpdate();⑴ > <YU'>%
//ps.addBatch();⑵ R.^]{ 5
} ^1S{::
//int [] counts = ps.executeBatch();⑶ ( eTrqI`
conn.commit(); xnZnbgO+
}catch(Exception e){ tAAMSb9[d
e.printStackTrace(); ..)J6L5l
} finally{ u<ed O+
try{ [CJ<$R !
if(ps!=null) { 8fXiadP#
ps.clearParameters(); :0J`4
ps.close(); PK[mf\G\
ps=null; ~[ufL25K
} a^R?w|zCX
}catch(SQLException e){} e(0OZ_ w
DBUtils.closeConnection(conn); Y9)j1~
} i0=U6S:#
} ;'7(gAE
public long getLast(){ >rd#,r
return lastExecuteTime; <s9{o
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} B>53+GyMV
public void run(){ W@d&X+7e
long now = System.currentTimeMillis(); =)Xj[NNRT
if ((now - lastExecuteTime) > executeSep) { %(YQ)=w
//System.out.print("lastExecuteTime:"+lastExecuteTime); Q~,Mzt"}W
//System.out.print(" now:"+now+"\n"); /v
8"i^;}
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 2HeX( rB
lastExecuteTime=now; xp^RAVXq`
executeUpdate(); WNyW1?"
} eAy,T<#
else{ `_\KN_-%Vu
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); gb_Y]U
} b>-DX
} "_WN[jm
} .#( vx;
//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 $[|(&8+7
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类写好了,下面是在JSP中如下调用。 *tXyd<_Hd
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<% K%z!#RyJ4
CountBean cb=new CountBean(); \L Q+
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ^DYS~I%s
CountCache.add(cb); AQ,lLn+
out.print(CountCache.list.size()+"<br>"); _Y; TS1u
CountControl c=new CountControl(); @](vFb
c.run(); c-+NWC
out.print(CountCache.list.size()+"<br>"); Btm,'kBG
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