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: j'hWhLax
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CountBean.java ,ei=w,O
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/* vL^ +X`.td
* CountData.java Dk8@x8
* U}5]Vm$]
* Created on 2007年1月1日, 下午4:44 rls{~ZRl
* {y%@1q%"
* To change this template, choose Tools | Options and locate the template under up0=Y
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* the Source Creation and Management node. Right-click the template and choose oJ/=&c
* Open. You can then make changes to the template in the Source Editor. -%{+\x2
*/ 4T
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package com.tot.count; {MDM= ;WP_
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/** <E^;RG
* _9Rj,
* @author H\9ePo\b~
*/ GZY:EHuz[
public class CountBean { 3*(><<ZC
private String countType; t=s.w(3t
int countId; 8LXK3D}?3
/** Creates a new instance of CountData */ I9`ZK2S
public CountBean() {} 9jNh%raG|
public void setCountType(String countTypes){ xh!T,|IR
this.countType=countTypes; aH8]$e8_,\
} -9o7a_Z
public void setCountId(int countIds){ AI9922}*
this.countId=countIds; YNKvR
} Cn5;h(r
public String getCountType(){ E0DquVrz
return countType; 1&9w]\Ae7l
} <p2\;\?4z
public int getCountId(){ _g,_G
return countId; c>+68<H
} *Ue#Sade
} D*sL&Rt][Y
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CountCache.java \%V !&
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/* W%o! m,zFM
* CountCache.java i<=2 L?[.I
* :()K2<E
* Created on 2007年1月1日, 下午5:01 av:%wJUl,$
* Ol|fdQ
* To change this template, choose Tools | Options and locate the template under 9JJ6$cLF
* the Source Creation and Management node. Right-click the template and choose vmo!
* Open. You can then make changes to the template in the Source Editor. NdXC8
*/ U!JmSP
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package com.tot.count; $*Wa A`(U
import java.util.*; gi)C5J4
/** +~M.VsX
* %kgT=<E'
* @author r@wE?hK
*/ TB84}
public class CountCache { 7;]IlR6
public static LinkedList list=new LinkedList(); F5M|QX@-
/** Creates a new instance of CountCache */ dX[Xe
public CountCache() {} >enP~uW[#
public static void add(CountBean cb){ <DII%7q,6/
if(cb!=null){ t? =V<Yd1
list.add(cb); 7vI
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} .SOCWznb
} N.SV*G
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} f rV_5yK'
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CountControl.java [TxvZq*4
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/* ,JPDPI/a
* CountThread.java ]g,j
* -B-HZ_
* Created on 2007年1月1日, 下午4:57 %>y!N!.F
* O(_f&a
* To change this template, choose Tools | Options and locate the template under O~6AX)|&=
* the Source Creation and Management node. Right-click the template and choose &lxMVynL
* Open. You can then make changes to the template in the Source Editor. vVsaGW
*/ Lw?>1rTT/
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package com.tot.count; IA}.{zY~|
import tot.db.DBUtils; 0TiDQ4}i[
import java.sql.*; 8&bNI@:@
/** .cmhi3o4
* yWr&G@>G
* @author {e0aH `me
*/ ^?0?*
public class CountControl{ 0$U\H>r
private static long lastExecuteTime=0;//上次更新时间 [DTe
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 L[Wi[S6=)g
/** Creates a new instance of CountThread */ WW7E*kc
public CountControl() {} >gn@NJ2 N
public synchronized void executeUpdate(){ xr!A>q+@i
Connection conn=null; ww'B!Ml>F
PreparedStatement ps=null; {`Mb ),G
try{ %0f*OC
conn = DBUtils.getConnection(); <N=ow"rD
conn.setAutoCommit(false); U-{3HHA
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 1WY$Vs
for(int i=0;i<CountCache.list.size();i++){ 8%MF<
CountBean cb=(CountBean)CountCache.list.getFirst(); p-7?S^!l
CountCache.list.removeFirst(); {WeRFiQ?-
ps.setInt(1, cb.getCountId()); =2}bQW
ps.executeUpdate();⑴ zXwdU58
//ps.addBatch();⑵ (;HO3Z".q$
} ";n%^I}
//int [] counts = ps.executeBatch();⑶ v)*eLX$
conn.commit(); *$mb~k^R
}catch(Exception e){ -}8r1jQH;
e.printStackTrace(); 'w|N}
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} finally{ SF[Z]|0gs
try{ qs9r$o.\l
if(ps!=null) { =Prz|
ps.clearParameters(); 5xH*&GpL7
ps.close(); GB6(WAmr
ps=null; HEK?z|Ne
} z34+1d
}catch(SQLException e){} x LK,Je
DBUtils.closeConnection(conn); ZalL}?E
?
} o+S?j*mv@
} Kf6D$}
public long getLast(){ fECmELd
return lastExecuteTime; nyG 5sWMpe
} M IU B]
public void run(){ Imo?)dYK
long now = System.currentTimeMillis(); %XXjQ5p
if ((now - lastExecuteTime) > executeSep) { |%(qaPA1
//System.out.print("lastExecuteTime:"+lastExecuteTime); l@@qpaH
//System.out.print(" now:"+now+"\n"); j?!/#'
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ;$4:
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lastExecuteTime=now; ~BXy)IB6
executeUpdate(); [-#q'S
} 6(q8y(.`
else{ u$ ^r(.EV
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); g{m~TVm'
} Vz y )jf
} pWb8X}M
} |j$$0N
//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 `3dGn.M
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类写好了,下面是在JSP中如下调用。 (~:ip)v
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<% yJ8_<A
CountBean cb=new CountBean(); '5 9{VA6h
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); [?)He} _L
CountCache.add(cb); :IozWPs*
out.print(CountCache.list.size()+"<br>"); S&'-wAEd
CountControl c=new CountControl(); -TyBb]
c.run(); ' KNg;
out.print(CountCache.list.size()+"<br>"); <!?ZH"F0
%>