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: '*b]$5*p
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CountBean.java FzJ7 OE|
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/* cl%+m
* CountData.java V]p{jLG
* Mu?|<#s
* Created on 2007年1月1日, 下午4:44 hL&$` Q
* 5 aA*
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* To change this template, choose Tools | Options and locate the template under hGz_F/
* the Source Creation and Management node. Right-click the template and choose Kp`{-dUf
* Open. You can then make changes to the template in the Source Editor. 5.9<g>C
*/ XVN`J]XHk
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package com.tot.count; ?q:|vt
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/**
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* %tyo(HZQ
* @author 43PLURay
*/ u=.8M`FxP
public class CountBean { `5IrV&a
private String countType; i41~-?Bc
int countId; OM*c7&
/** Creates a new instance of CountData */ y?<KN0j
public CountBean() {} %y6(+I#P
public void setCountType(String countTypes){ Qq<@;4
this.countType=countTypes; gc.Lh~
} &J>e;X
public void setCountId(int countIds){ N*o{BboK;
this.countId=countIds; f"ndLX:'}
} q!ZM Wg
public String getCountType(){ |58HPW9
return countType; !ZYPz}&N_
} 0<uek
public int getCountId(){ Ek_5% n
return countId; y7,I10:D
} }5;4'l8
} >rCD5#DG
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CountCache.java y|5L%,i
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/* r/j:A#6M]o
* CountCache.java bv[#|^/
* 9n&
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* Created on 2007年1月1日, 下午5:01 8 "l
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* m\6/:~qWW
* To change this template, choose Tools | Options and locate the template under }/cReX,so
* the Source Creation and Management node. Right-click the template and choose i2,4:M)CV
* Open. You can then make changes to the template in the Source Editor. 1RRE{]2v#
*/ Y![Q1D!
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package com.tot.count; v>8C}d^
import java.util.*; @+gr/Pul^
/** J}#gTG( '
* ?=? _32O
* @author g#J`7n
*/ PI9,*rOy
public class CountCache { {&=+lr_h?
public static LinkedList list=new LinkedList(); YB 38K(
/** Creates a new instance of CountCache */ TN(Vzs%
public CountCache() {} DB/~Z
public static void add(CountBean cb){ &93{>caf+
if(cb!=null){ 7Sx|n}a-3
list.add(cb); z'YWomfZm
} ,;$OaJFT
} gP2zDI
} tT}b_r7h(1
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CountControl.java +Nt4R:N
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/* ~g{j)"1
* CountThread.java im<bo Mv
* v:t;Uk^Y
* Created on 2007年1月1日, 下午4:57 M3tl4%j
* a:BW*Hy{\
* To change this template, choose Tools | Options and locate the template under )1s5vNVa
* the Source Creation and Management node. Right-click the template and choose ^A$=6=CX
* Open. You can then make changes to the template in the Source Editor. DrJ?bG;[
*/ d:%b
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package com.tot.count;
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import tot.db.DBUtils; \|HEe{nA
import java.sql.*; $n\P w
/** ]auvtm-[
* h `Lr5)B'
* @author $}9jv3>)
*/ 6'^_*n
public class CountControl{ 9@ k8$@
private static long lastExecuteTime=0;//上次更新时间 ]o6ZZK
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 vqm|D&HU
/** Creates a new instance of CountThread */ vpQ&vJfR
public CountControl() {} TeHJj`rdAU
public synchronized void executeUpdate(){ O~3
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Connection conn=null; O^L]2BVC
PreparedStatement ps=null; i2=- su
try{ W/Dd7G#IC
conn = DBUtils.getConnection(); dGUP|O
conn.setAutoCommit(false); 0AQazhm
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 6G8No-#y
for(int i=0;i<CountCache.list.size();i++){ Rb6BY-/J
CountBean cb=(CountBean)CountCache.list.getFirst(); `3;EJDEdbi
CountCache.list.removeFirst(); l6 G6H$
ps.setInt(1, cb.getCountId()); l_g$6\&|
ps.executeUpdate();⑴ q$:1Xkl
//ps.addBatch();⑵ RkYdK$|K
} Y%KowgP\
//int [] counts = ps.executeBatch();⑶ %7#<K\])
conn.commit(); ;UQGi}?CD
}catch(Exception e){ %_(vSpk
e.printStackTrace(); FM{f{2j
} finally{ N!+=5!
try{ ) /raTD
if(ps!=null) { cl& w/OJ#
ps.clearParameters(); 6S`_L
ps.close(); \<7Bx[/D4
ps=null; /Hr|u
} B2;P%B
}catch(SQLException e){} uo"<}>iJ
DBUtils.closeConnection(conn); 1&w%TRC2x
} Y~"tL(WfJl
} gIB3DuUo
public long getLast(){ P5Xp #pa
return lastExecuteTime; $qNF /rF
} IiPX`V>RC
public void run(){ %2QGbnt_*
long now = System.currentTimeMillis(); I9X\@lTf
if ((now - lastExecuteTime) > executeSep) { @6;OF5VsQ
//System.out.print("lastExecuteTime:"+lastExecuteTime); `<7\Zl
//System.out.print(" now:"+now+"\n"); ]Lv P)0=
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); S\GWMB!oF
lastExecuteTime=now; 8E%LhA.
executeUpdate(); #(^<qr
} |AYii-g
else{ *C_A(n5"V
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); mskG2mA
} 4.O) /0sU
} #C9f?fnM
} f_~T
//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 ;hT3N UCA
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类写好了,下面是在JSP中如下调用。 C[7!pd
JwG(WLb:
<% U0&myj 8L
CountBean cb=new CountBean(); _Ewh:IM-
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); %' DOFiU
CountCache.add(cb); #Vk?
out.print(CountCache.list.size()+"<br>"); "laf:Ty1
CountControl c=new CountControl(); *AH`ob}
c.run(); 4|x_C-@
out.print(CountCache.list.size()+"<br>"); t&?jJ7 (&8
%>