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: 04@cLDX8uB
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CountBean.java EL{vFP
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/* ip:LcG t
* CountData.java ;;U:Jtn2
* tkKJh !Q7
* Created on 2007年1月1日, 下午4:44 {6Au3gt/
* !CY&{LEYn0
* To change this template, choose Tools | Options and locate the template under [iS$JG-
* the Source Creation and Management node. Right-click the template and choose iCQ>@P]nE
* Open. You can then make changes to the template in the Source Editor. 7jG(<!,
*/ ROb\Rxm
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package com.tot.count; !{%: qQiA
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/** dJk9@u
* ,!QV>=
* @author K7)kS
*/ {dWObh
public class CountBean { r6.d s^
private String countType; ~/#1G.H
int countId; mTDVlw0dh
/** Creates a new instance of CountData */ e@<?zS6
public CountBean() {} /n,a?Ft^N)
public void setCountType(String countTypes){ 6"
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this.countType=countTypes; 5<YzalNf
} V9%aBkf8w
public void setCountId(int countIds){ ?&+9WJ<M
this.countId=countIds; :!TIK1
} FY3IUG
public String getCountType(){ qSU|=
return countType; ?h8{xa5b
} 8{
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public int getCountId(){ [:EvTY
return countId; ]ZoPQUS?
} pox,Im
} R{hf9R ,
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CountCache.java sy5 Fn~\R
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/* ^"8wUsP
* CountCache.java b{7E;KyY,
* IVxWxM*N<
* Created on 2007年1月1日, 下午5:01 s][24)99
* X@A1#z+s0]
* To change this template, choose Tools | Options and locate the template under %eWqQ3{P]
* the Source Creation and Management node. Right-click the template and choose }Fb!?['G5
* Open. You can then make changes to the template in the Source Editor. 4"?^UBr
*/ SX0_v_%M
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package com.tot.count; ~aK?cP
import java.util.*; qt e>r
/** qOhO qV
* )X+mV
* @author [5d2D,)
*/ a*dQ
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public class CountCache { oMH.u^b]fT
public static LinkedList list=new LinkedList(); ^%T7. 1'x
/** Creates a new instance of CountCache */ io2)1cE&f
public CountCache() {} R!\EKH
public static void add(CountBean cb){ .p`
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if(cb!=null){ :Ixx<9c.
list.add(cb); 9"{W,'r&d
} j7QX,_Q
} ?uL eFD
} uzr\oj+>
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CountControl.java S::=85[>z
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/* 32)tJ|m
* CountThread.java QCOo
* ^rNUAj9Z
* Created on 2007年1月1日, 下午4:57 p*QKK@C
* <[ Xw)/#
* To change this template, choose Tools | Options and locate the template under A#wEuX=[
* the Source Creation and Management node. Right-click the template and choose I3b"|%
* Open. You can then make changes to the template in the Source Editor. [I*!
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*/ mB'3N;~
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package com.tot.count; v-j3bB
import tot.db.DBUtils; \K2*Q&>
import java.sql.*; o89(
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/** z9/G4^qF
* BHDML.r }M
* @author 9=l.T/?sf
*/ JAc_kl{4O
public class CountControl{ R[tC^]ai
private static long lastExecuteTime=0;//上次更新时间 \*vHB`.,ey
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Nh?|RE0t
/** Creates a new instance of CountThread */ QbFHfA2Ij
public CountControl() {} q<vf,D@{ !
public synchronized void executeUpdate(){ I&yVx8aH}
Connection conn=null; Wzq>JNny
PreparedStatement ps=null; c~}l8M%
try{ Tb;d.^
conn = DBUtils.getConnection(); upn~5>uCP
conn.setAutoCommit(false); \ gwXH
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); J97R0
for(int i=0;i<CountCache.list.size();i++){ koG{
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CountBean cb=(CountBean)CountCache.list.getFirst(); ]$-cMX
CountCache.list.removeFirst(); 8TV;Rtl
ps.setInt(1, cb.getCountId()); 6rti '
ps.executeUpdate();⑴ )KSoq/
//ps.addBatch();⑵ K+\nC)oG
} AEirj /
//int [] counts = ps.executeBatch();⑶ 3L>IX8_
conn.commit(); '_s}o<
}catch(Exception e){ {Bvj"mL]j
e.printStackTrace(); F?+3%>/A@
} finally{ {BBw$m, o
try{ RrrK*Fk8=
if(ps!=null) { unl1*4e+
ps.clearParameters(); K]oM8H1
ps.close(); ^y.nDs%ZT7
ps=null; C2U~=q>>
} gApoX0nrv
}catch(SQLException e){} 0Wvq>R.(]7
DBUtils.closeConnection(conn); B0}~G(t(
} -XK0KYhgW
} F4#g?R::U
public long getLast(){ YB))S!;Ok
return lastExecuteTime; ^WYQ]@rh3
} QWnndI_4p
public void run(){ R@Y=o].2
long now = System.currentTimeMillis(); MZv]s
if ((now - lastExecuteTime) > executeSep) { UM%o\BiO
//System.out.print("lastExecuteTime:"+lastExecuteTime); _mE^rT
//System.out.print(" now:"+now+"\n"); 2/P"7A=<
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Et2JxbD
lastExecuteTime=now; kT IYD o
executeUpdate(); :t$aN|>y
} ihe(F7\U
else{ 9v)%dO.
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); R,2=&+ e
} D>L2o88
} ]
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} \{\MxXW
//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 hn)a@
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类写好了,下面是在JSP中如下调用。 &-yGVx
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<% q0mOG^
CountBean cb=new CountBean(); l;X|=eu'
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ?8@>6IXn
CountCache.add(cb); Ds8
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out.print(CountCache.list.size()+"<br>"); sRHA."A!8
CountControl c=new CountControl(); R0Ue0pF7
c.run(); 8iQ[9
out.print(CountCache.list.size()+"<br>"); Cr/`keR
%>