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: v,r}q1.E}
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CountBean.java %*P59%
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/* mnL
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* CountData.java \Q{@AC<?i
* vTjgW?9
* Created on 2007年1月1日, 下午4:44 HyXw^ +tsj
* "!XeK| Wi
* To change this template, choose Tools | Options and locate the template under 0Mt2Rg}
* the Source Creation and Management node. Right-click the template and choose B{!)GZ(}
* Open. You can then make changes to the template in the Source Editor. NAhV8
*/ jD3,z*
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package com.tot.count; 0CI?[R\
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/** =If % m9
* C1P{4 U
* @author 7P9n.
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*/ Vn? %w~0!
public class CountBean { I"@X~Y7}
private String countType; }GsZ)\!$4
int countId; -h*Yd)
/** Creates a new instance of CountData */ >b,o yM
public CountBean() {} dN;kYWRK
public void setCountType(String countTypes){ AL! ^1hCF
this.countType=countTypes; g~.,-V}
} `|wH=
public void setCountId(int countIds){ `LH!"M
this.countId=countIds; sW+YfJT
} SqFya
public String getCountType(){ b$[_(QUw
return countType; 8,YF>O&
} ]R}#3(]1
public int getCountId(){ Ri4_zb
return countId; UT [7 J
} VP\HPSp
} rB?u.jn0T
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CountCache.java rMSB|*_
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/* Km]N scq1
* CountCache.java F}0QocD
* gB&]kHLO
* Created on 2007年1月1日, 下午5:01 5}9-)\8=z
* k@5#^G
* To change this template, choose Tools | Options and locate the template under u1`8f]qt
* the Source Creation and Management node. Right-click the template and choose J"|)?$d]z
* Open. You can then make changes to the template in the Source Editor. <qZXpQ#
*/ ,oIZ5u{#,
jd l1Q<Z
package com.tot.count; =nFT0];
import java.util.*; nSsVONHfa
/** NmST1pMk
* = Ii@-C
* @author i2.y)K)
*/ Zqd&EOm
public class CountCache { ,Ng3!2&$e
public static LinkedList list=new LinkedList(); =b32E^z,
/** Creates a new instance of CountCache */ y4VCehdJ
public CountCache() {} <?52Svi}}
public static void add(CountBean cb){ -QIcBzw;q
if(cb!=null){ cZ|D!1%
list.add(cb); yt>Pf<AI
} yNc>s/
} <Nvw
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} -6~*:zg,
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CountControl.java nen6!bw4
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/* b-]E-$Uz
* CountThread.java &Xe r#6~
* s7I*=}{g0.
* Created on 2007年1月1日, 下午4:57 PZNo.0M70
* =/6.4;8
* To change this template, choose Tools | Options and locate the template under |{PQ0DS
* the Source Creation and Management node. Right-click the template and choose E2(;R!ML#
* Open. You can then make changes to the template in the Source Editor. }yx{13:[
*/ cLr? B;FS
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package com.tot.count; (m)%5*:
import tot.db.DBUtils; $DA0lY\
import java.sql.*; #H
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/** z(.$>O&6H
* z$ysp!
* @author KyXgw
*/ :m8ED[9b
public class CountControl{ ||`w MWq
private static long lastExecuteTime=0;//上次更新时间 n#z^uq|v
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 |GK [I
/** Creates a new instance of CountThread */ 3mWo`l
public CountControl() {} rctn0*MP
public synchronized void executeUpdate(){ _QvyFKAM
Connection conn=null; gK(E0p"
PreparedStatement ps=null; gywI@QD%#
try{ *Q!b%DIa$
conn = DBUtils.getConnection(); r{\cm
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conn.setAutoCommit(false); [.6>%G1C
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); kjNA~{
for(int i=0;i<CountCache.list.size();i++){ Zt lS*id_
CountBean cb=(CountBean)CountCache.list.getFirst(); ]|u}P2
CountCache.list.removeFirst(); kUP[&/Lc
ps.setInt(1, cb.getCountId()); Pdf_{8r
ps.executeUpdate();⑴ sB0+21'R
//ps.addBatch();⑵ ?jqZeO#W7
} ivoPl~)J
//int [] counts = ps.executeBatch();⑶ nyQFS
conn.commit(); WcH^bAY 6
}catch(Exception e){ H7Y}qP5X
e.printStackTrace(); 4c2P%X(
C
} finally{ &tWWb`
try{ JTx}{kVO
if(ps!=null) { fEVuH]
ps.clearParameters(); 0p2 0Rt
ps.close(); QMtt:f]?i
ps=null; {)b`fq
} ljiq +tT
}catch(SQLException e){} OzO_E8Kb\
DBUtils.closeConnection(conn); ]XPGlM
} bx6@FKns}
} 7[D0n7B@
public long getLast(){ C{!Czz.N
return lastExecuteTime; *D AgcB
} ]VwAHT&je
public void run(){ `b\4h/~
long now = System.currentTimeMillis(); ^iV@NVP
if ((now - lastExecuteTime) > executeSep) { z7<^aS
//System.out.print("lastExecuteTime:"+lastExecuteTime); N->;q^
//System.out.print(" now:"+now+"\n"); 2CmeO&(Qf*
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); <ht>>
lastExecuteTime=now; Phb<##OB
executeUpdate(); T&R`s+7
} ~B=\![
else{ 2~ 'Q#(
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); #m$H'O[WG\
} xje{kx#
} yLDHJ}R
} ,7j`5iq[m
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 fx;5j;
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类写好了,下面是在JSP中如下调用。 ..~{cU4Tt
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<% z9D2,N.
CountBean cb=new CountBean(); (XW#,=rYk
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); spl*[ d
CountCache.add(cb); 9&d BL0
out.print(CountCache.list.size()+"<br>"); |HG%o
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CountControl c=new CountControl(); qS2%U?S7
c.run(); ux=a9
out.print(CountCache.list.size()+"<br>"); yBl<E$=
%>