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: eO*FoN
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CountBean.java \[Q,>{^
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/* pvcD
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* CountData.java &t`l,]PQ=6
* lh
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* Created on 2007年1月1日, 下午4:44 {6RT&w
* %kyvtt
* To change this template, choose Tools | Options and locate the template under Es)Kw3^a
* the Source Creation and Management node. Right-click the template and choose KecR jon ~
* Open. You can then make changes to the template in the Source Editor. 8*lVO2
*/ 'w&,3@Z
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package com.tot.count; c!j$-Ovm
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/** S\mh{#Lpk
* 1*#64Y5F
* @author qA5tMZ^w
*/ RtN5\
public class CountBean { 6=iz@C7r
private String countType; f7\$rx
int countId; JZ9w!)U
/** Creates a new instance of CountData */ wOn.m
public CountBean() {} |tyVC=${
public void setCountType(String countTypes){ (Y:5u}*Y
this.countType=countTypes; cbNrto9
} 6 fL=2a
public void setCountId(int countIds){ xa ??OT`(
this.countId=countIds; H71LJfH
} Koo%mr
public String getCountType(){ y&UcTE2;%(
return countType; N<9CV!_
} R9^Vk*`gFU
public int getCountId(){ ZI}7#K<9X
return countId; e'p'{]r<w
} l7n c8K
} 6gNsh
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CountCache.java HW)> `
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/* [a`89'"z
* CountCache.java >6KuZ_
* 7gNJ}pLDx
* Created on 2007年1月1日, 下午5:01 Nxp7/Nn3
* 1@egAo)
* To change this template, choose Tools | Options and locate the template under 1 VcZg%I
* the Source Creation and Management node. Right-click the template and choose )|zLjF$
* Open. You can then make changes to the template in the Source Editor. Etj@wy/E
*/ 2ntL7F<ow
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package com.tot.count; 4v_<<l
import java.util.*; FxW~Co
/** 3)3?/y)_
* ~ep-XO
* @author uD}Q}]Z
*/ 6* (6>F5
public class CountCache { a~>+I~^K5q
public static LinkedList list=new LinkedList(); 9'Le}`Gf
/** Creates a new instance of CountCache */ XShi[7
public CountCache() {} -c{O!z6sX
public static void add(CountBean cb){ fp^{612O?
if(cb!=null){
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list.add(cb); eVGO6 2|!
} jb|al[p\
} 0Q`Dp;a5&
} UP' ~D]J
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CountControl.java V:s$V.{!
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/* 0}$Zr*|;Y
* CountThread.java B<zoa=
* >g+yw1nC
* Created on 2007年1月1日, 下午4:57 ~4fUaMT
* P{-j^'y
* To change this template, choose Tools | Options and locate the template under 4YX/=
* the Source Creation and Management node. Right-click the template and choose /H3z~PBa
* Open. You can then make changes to the template in the Source Editor. 1DLAfsLlj
*/ ])`w_y(>
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package com.tot.count; l!qhK'']V"
import tot.db.DBUtils; @cRR
import java.sql.*; lY
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/** D`d*bNR
* A#k(0e!O
* @author
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*/ Di)%vU
public class CountControl{ 3b{ 7Z 2
private static long lastExecuteTime=0;//上次更新时间 wz`\RHL
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 amvD5
/** Creates a new instance of CountThread */ Mu: y9o95
public CountControl() {} }:+SA
public synchronized void executeUpdate(){ QP>tu1B|
Connection conn=null; IyK^` y
PreparedStatement ps=null; 6Ft?9
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try{ 0gTv:1F/
conn = DBUtils.getConnection(); WVZ](D8Gc]
conn.setAutoCommit(false); [`J91=
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Ec'Hlsgh&T
for(int i=0;i<CountCache.list.size();i++){ RRRF/Z;))
CountBean cb=(CountBean)CountCache.list.getFirst(); !B|Aq-
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CountCache.list.removeFirst(); X(Z~oGyg
ps.setInt(1, cb.getCountId()); b'r</ncZ
ps.executeUpdate();⑴ *yl?M<28
//ps.addBatch();⑵ #z6[8B
} G`D rY;
//int [] counts = ps.executeBatch();⑶ UlP2VKM1&
conn.commit(); S3oyx#R('O
}catch(Exception e){ aQ.QkMZ
e.printStackTrace(); `)~]3zmG
} finally{ p>oC.[:4a
try{ #ME!G/
if(ps!=null) { "%peYNZ&%
ps.clearParameters(); Fc&3tw"g
ps.close(); 76::X:76
ps=null; d?ru8
} _+7+90u
}catch(SQLException e){} 2JdzeJb
DBUtils.closeConnection(conn); S@Iza9\|@
} A>\5fO
} eR3v=Q
public long getLast(){ kI?+\k\V`
return lastExecuteTime; u*}ltR~/
} atiyQuT6Wh
public void run(){ h*>%ou
long now = System.currentTimeMillis(); /O[<"Wcz
if ((now - lastExecuteTime) > executeSep) { t|PQ4g<
//System.out.print("lastExecuteTime:"+lastExecuteTime); ~7=eHU.@
//System.out.print(" now:"+now+"\n"); yE&WGpT
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); -.@dA'j[
lastExecuteTime=now; B%7Az!GX
executeUpdate(); /
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} Iip%er%b
else{ |lCS^bA3
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 5bB\i79$
} &x9>8~
} &2,3R}B/
} .}9Lj
//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 ^r=Wj@`
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类写好了,下面是在JSP中如下调用。 %1oB!+tv
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<% hv0bs8h
CountBean cb=new CountBean(); oyT`AYa
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); dy>5LzqK3
CountCache.add(cb); K/iFB
out.print(CountCache.list.size()+"<br>"); :
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CountControl c=new CountControl(); n1U! od
c.run(); \wV^uS
out.print(CountCache.list.size()+"<br>"); O=[Q>\p
%>