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: XQ>m8K?\d
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CountBean.java -VL3em|0
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/* #\qES7We6
* CountData.java MeC@+@C
* oID,PB*9
* Created on 2007年1月1日, 下午4:44 &LE/hA
* wbTw\b=
* To change this template, choose Tools | Options and locate the template under 7o3f5"z
* the Source Creation and Management node. Right-click the template and choose *" wsMO
* Open. You can then make changes to the template in the Source Editor. NeH^g0Q2,g
*/ Jc*A\-qC.
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package com.tot.count; bA:abO
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/** wXe.zLQ
* 8l6R.l
* @author 1QThAFN
*/ :7gIm|2"]
public class CountBean { {8eNQ-4I
private String countType; sqhM[u
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int countId; }QK-@T@4<
/** Creates a new instance of CountData */ o 0B`~7(
public CountBean() {} B4%W,F:@
public void setCountType(String countTypes){ \RJ428sxn
this.countType=countTypes; w5p+Yx=q
} [1Rs~T"
public void setCountId(int countIds){ ]*).3<Lw
this.countId=countIds; #H|]F86 (
} bLg1Dd7Q
public String getCountType(){ 5^qI6
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return countType; 0=NB[eG
} PM{kiz^
public int getCountId(){ ?o2L
return countId; #-{4F?DA]y
} b$hQB090
} 'Q# KjY
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CountCache.java ral0@\T
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/* ` 6PdMvF
* CountCache.java rLVS#M#&e>
* q*>`HTPcU
* Created on 2007年1月1日, 下午5:01 O3S_P]{*ny
* mU;TB%#)
* To change this template, choose Tools | Options and locate the template under yA~W|q(/V
* the Source Creation and Management node. Right-click the template and choose N7XRk=J
* Open. You can then make changes to the template in the Source Editor. Y:O%xtGi
*/ g94NU
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package com.tot.count; L49`=p<
import java.util.*; _ 95V"h
/** /IODRso/!
* ^XV$J-
* @author {C
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*/ [!"u&iu`
public class CountCache { C Z|R-ky6p
public static LinkedList list=new LinkedList(); l78zS'
/** Creates a new instance of CountCache */ vNP,c]:%
public CountCache() {} Zx@{nVoYe~
public static void add(CountBean cb){ EI'(
if(cb!=null){ N/(&&\3
list.add(cb); OX!9T.j
} e(cctC|l
} n(&6E3ZcI
} ;sDFTKf
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CountControl.java I_4'9
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/* P7Kp*He)
* CountThread.java 99vm7"5 hQ
* m3 ,i{
* Created on 2007年1月1日, 下午4:57 YoJN.],gf
* +`zM^'^$
* To change this template, choose Tools | Options and locate the template under -3A#a_fu
* the Source Creation and Management node. Right-click the template and choose xI$B",?(
* Open. You can then make changes to the template in the Source Editor. U)2\=%8
*/ M '[.ay
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package com.tot.count; CtS*"c,j
import tot.db.DBUtils; u9 J;OsnHK
import java.sql.*; F4@``20|
/** WI' ;e4
* *G^QS"%
* @author s/8>(-H#
*/ iphe0QE[#}
public class CountControl{ x,pzX(
private static long lastExecuteTime=0;//上次更新时间 a8''t_Dp
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 vk&C'&uV9@
/** Creates a new instance of CountThread */ IZ"d s=w
public CountControl() {} jU/0a=h9
public synchronized void executeUpdate(){ p \1-.
Connection conn=null; <rNCb;
PreparedStatement ps=null; }sZme3*J[
try{ y]yp8Bs+
conn = DBUtils.getConnection(); x pT85D
conn.setAutoCommit(false); #)z_TM07P
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); pPUKx=d
for(int i=0;i<CountCache.list.size();i++){ zrri&QDF<
CountBean cb=(CountBean)CountCache.list.getFirst(); d?S7E
q9`
CountCache.list.removeFirst(); SnRk` 5t
ps.setInt(1, cb.getCountId()); l-g+E{ZM
ps.executeUpdate();⑴ I8rtta
//ps.addBatch();⑵ "aHA6zTB
} 4fgA3%
//int [] counts = ps.executeBatch();⑶ '7 SFa]tH
conn.commit(); C[z5&
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}catch(Exception e){ t[|^[%i
e.printStackTrace(); q3n(Z
} finally{ )Z2HzjE
try{ X H,1\J-S
if(ps!=null) { F<VoPqHq
ps.clearParameters(); u?r=;:N|y
ps.close(); *H8(G%a!^
ps=null; G$( B26
} ,SNN[a
}catch(SQLException e){} D<78Tm
x
DBUtils.closeConnection(conn); sE{A~{a`
} ]X%T^3%G
} 9q(*'rAm
public long getLast(){ >fNRwmi
return lastExecuteTime; V*U{q%p(
} Ey4%N`H-^
public void run(){
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long now = System.currentTimeMillis(); gP:mZ7
if ((now - lastExecuteTime) > executeSep) { kdcr*7w
//System.out.print("lastExecuteTime:"+lastExecuteTime); ]lV\D8#
//System.out.print(" now:"+now+"\n"); PRa#;Wb
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); B@U;[cO&
lastExecuteTime=now; Zl^#U c"
executeUpdate(); bxLeQWr6
} )2~Iqzc4
else{ Ev+m+
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Z:j6AF3;
} b=(?\
} QpbyC_:;$4
} '7Q5"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 z]:{ruvH
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类写好了,下面是在JSP中如下调用。 .93B@u
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<% d[eN#<
CountBean cb=new CountBean(); (r78AZ
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); qRC-+k:
CountCache.add(cb); oP vk ^H
out.print(CountCache.list.size()+"<br>"); '@t}8J
CountControl c=new CountControl(); K)"lq5nM
c.run(); 0<(F
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out.print(CountCache.list.size()+"<br>");
p}I,!~}
%>