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: aC%&U4OS
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CountBean.java c!#:E`
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/* A1"SLFY
* CountData.java P 43P]M2
* &V7M}@
* Created on 2007年1月1日, 下午4:44 ? *>]")[>
* H/+B%2Zj
* To change this template, choose Tools | Options and locate the template under gw36Ec<M
* the Source Creation and Management node. Right-click the template and choose h[o6-f<D
* Open. You can then make changes to the template in the Source Editor. ,m_WR7!$E
*/ 8CbXMT
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package com.tot.count; S35~Cp
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/** [F!Y%Zp
* 1rKy@9
* @author R:X0'zeRr
*/ */:uV
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public class CountBean { ]:>,A@7
private String countType; qz?mh4Oh
int countId; bKg8rK u
/** Creates a new instance of CountData */ a.N{-2ptH
public CountBean() {} L){iA-k;Ec
public void setCountType(String countTypes){ yAL[[
this.countType=countTypes; >NYW{(j
} a=cvCf
public void setCountId(int countIds){ 'R-3fO???
this.countId=countIds; hj'(*ND7z
} *g?Po+ef%
public String getCountType(){ )e5 @
return countType; pRkP~ZISU
} IxLhU45
public int getCountId(){ .7K7h^*F
return countId; T,aW8|
} Z}$TKO*u
} nRyU]=-X
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CountCache.java -f*P
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/* y=?)n\f
* CountCache.java '>r7V
*
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* Created on 2007年1月1日, 下午5:01 0a80 LAK
* ggJO:$?$L
* To change this template, choose Tools | Options and locate the template under ^0/j0]O
* the Source Creation and Management node. Right-click the template and choose !pD*p)`s
* Open. You can then make changes to the template in the Source Editor. ,l<6GB2\
*/ ty8v
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package com.tot.count; xlQBe-Wg
import java.util.*; ~ 4kc/a
/** [VE8V-
* 7(pF[LCF
* @author 6Vz9?puD
*/ q
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public class CountCache { ZIQ
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public static LinkedList list=new LinkedList(); oH_;4QU4y
/** Creates a new instance of CountCache */ !QvZ<5(
public CountCache() {} <yd{tD$A*
public static void add(CountBean cb){ zG(\+4GE!
if(cb!=null){ 9jw\s P@
list.add(cb); YJ\Xj56gv
} \--8lH -K
} ' ~8KSF*!p
} #3gp6*R
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CountControl.java b:TLV`>/&
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/* 7eAX*Kgt<_
* CountThread.java -4
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* ]@phF _
* Created on 2007年1月1日, 下午4:57 (jAg_$6
* h-`}L=
* To change this template, choose Tools | Options and locate the template under [D\k^h
* the Source Creation and Management node. Right-click the template and choose -w"VK|SGm
* Open. You can then make changes to the template in the Source Editor. ui/a|Q
*/ wY[+ZT
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package com.tot.count; ]SLP}Jwy
import tot.db.DBUtils; H"
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import java.sql.*; cWe"%I
/**
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* YwjKAyLU
* @author @eKec1<
*/ X:nN0p #
public class CountControl{ Ezd_`_@R
private static long lastExecuteTime=0;//上次更新时间 paCV!tP
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 j}.\]$J
/** Creates a new instance of CountThread */ $#9;)8J
public CountControl() {}
/} b03
public synchronized void executeUpdate(){ $Avjnm
Connection conn=null; B#Vz#y
PreparedStatement ps=null; /rnu<Q#iH
try{ {Tq_7,8
conn = DBUtils.getConnection(); VJ]JjB
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conn.setAutoCommit(false); $QLcH;+7t
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); svcK?^
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for(int i=0;i<CountCache.list.size();i++){ 0=2@
CountBean cb=(CountBean)CountCache.list.getFirst(); 3z{?_;bR
CountCache.list.removeFirst(); A>o*t=5
ps.setInt(1, cb.getCountId()); ) l:[^$=,
ps.executeUpdate();⑴ eg;~zv
//ps.addBatch();⑵ \/zq7j
} OR~8sU
//int [] counts = ps.executeBatch();⑶ l5!|I:/*;
conn.commit(); 7:plQ!7^
}catch(Exception e){ >UiYL}'br6
e.printStackTrace();
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} finally{ MyJ%`@+1
try{ N8F~8lTi
if(ps!=null) { *x@Onj
ps.clearParameters(); Ug>~Rq]
ps.close(); 8lvV4yb
ps=null; 4'/nax$Bx;
} E7j(QOf
}catch(SQLException e){} *\+\5pu0
DBUtils.closeConnection(conn); .,<1%-R34q
} M ?Y;a5{
} [8 ]z|bM
public long getLast(){ [=6]+V83M
return lastExecuteTime; /?5 1D@
} gc_:%ki
public void run(){ naG=Pq<
long now = System.currentTimeMillis(); <J<{l
if ((now - lastExecuteTime) > executeSep) { _|kxY'_[8
//System.out.print("lastExecuteTime:"+lastExecuteTime); z+0I#kM"1
//System.out.print(" now:"+now+"\n"); /M1ob: m
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); @vC4[:"pD}
lastExecuteTime=now; _{I3i:f9X8
executeUpdate(); +~m46eI
} ##,a0s^
else{ [M]
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ?PuBa`zDE
} }eCw6
} :C(=&g<]D
} b|l:fT?&
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 vOn`/5-
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类写好了,下面是在JSP中如下调用。 DU0zez I9
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<% d[@X%
CountBean cb=new CountBean(); >K_(J/&p
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); |7'df &CA
CountCache.add(cb); !,wIQy_e4
out.print(CountCache.list.size()+"<br>"); ? &o2st
CountControl c=new CountControl(); I5k$H$
c.run(); b z`+ k,*
out.print(CountCache.list.size()+"<br>"); \pa"%c)
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