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: $Ha?:jSc
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CountBean.java %p"x|e
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/* a@zKi;
* CountData.java 2Ua_7
* \P!v9LX(
* Created on 2007年1月1日, 下午4:44 LLg ']9
* TclZdk]%T
* To change this template, choose Tools | Options and locate the template under b]~X
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* the Source Creation and Management node. Right-click the template and choose 7*OO k"9
* Open. You can then make changes to the template in the Source Editor. 5?k_Q"~
*/ =ALy.^J=
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package com.tot.count; _x z_D12
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/** `?rPs8+R
* @fT*fv
* @author :q;vZ6Xd
*/ Vlce^\s;
public class CountBean { (iGk]Rtzt
private String countType; 5|xFY/%
int countId; G-Z_pGer^
/** Creates a new instance of CountData */ 9+9}^B5@A
public CountBean() {} '/b,3:
public void setCountType(String countTypes){ $WnK
this.countType=countTypes; #@Zz
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} B[C2uVEX:
public void setCountId(int countIds){ G?e,Q$
this.countId=countIds; q+dY&4&u
} H]"Z_n_
public String getCountType(){ s[h'W~
return countType; -n!.PsGO>
} }0?642 =-
public int getCountId(){ +KDB^{
return countId; <|Bh;;
} O9A.WSJ
>}
} }{:H0)H*
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CountCache.java X~5TA)h;~
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/* xx
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* CountCache.java fV
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* e<l Wel
* Created on 2007年1月1日, 下午5:01 DM! vB+j+,
* #It{B
* To change this template, choose Tools | Options and locate the template under aT(Pf7
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* the Source Creation and Management node. Right-click the template and choose v/8K?$"q
* Open. You can then make changes to the template in the Source Editor. zkI\ji
*/ Jm\'=#U#
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package com.tot.count; `HgT5}
import java.util.*; /%$'N$@f
/** Cq u/(=
* iF{eGi
* @author )1lR;fD
*/ .gv J;A7
public class CountCache { 4cr
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public static LinkedList list=new LinkedList(); W4QVWn %3
/** Creates a new instance of CountCache */ P00d#6hPJ
public CountCache() {} +J]3)8y+
public static void add(CountBean cb){ 7zVaj"N(
if(cb!=null){ 8 ]dhNA5
list.add(cb); p<`q^D
} ,/m<= `*N|
} Io5-[d
} |
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CountControl.java JnmJN1@I
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/* ,78QLh9:
* CountThread.java my[)/'
* +T
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* Created on 2007年1月1日, 下午4:57 5X|=qZ
* I^[R]Js
* To change this template, choose Tools | Options and locate the template under /o.wCy,J<
* the Source Creation and Management node. Right-click the template and choose E[Tz%x=P
* Open. You can then make changes to the template in the Source Editor. Z%N{Y x(
*/ G!8O*4+A
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package com.tot.count; WsL*P.J
import tot.db.DBUtils; d&wg\"E
import java.sql.*; O=MO M
/** MQD UJ^I$
* >VE,/?71@
* @author G! zV=p
*/ %TPnC'2
public class CountControl{ Zu_m$Mx
private static long lastExecuteTime=0;//上次更新时间 Q68&CO(rE
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 W~POS'1
/** Creates a new instance of CountThread */ 1V+a;-?
public CountControl() {} +AtZltM i
public synchronized void executeUpdate(){ IW
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Connection conn=null; tcwE.>5O
PreparedStatement ps=null; )2g\GRg6
try{ 9|D!&=8
conn = DBUtils.getConnection(); n9050&_S
conn.setAutoCommit(false); }7IS:"tu
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); j7xoe9;TxI
for(int i=0;i<CountCache.list.size();i++){ ch 4z{7
CountBean cb=(CountBean)CountCache.list.getFirst(); 82YTd(yB
CountCache.list.removeFirst(); $s/N;E!t
ps.setInt(1, cb.getCountId()); 9-Ikd>9
ps.executeUpdate();⑴ tt{,f1v0t
//ps.addBatch();⑵ .2C}8GGC'
} gvr"F
//int [] counts = ps.executeBatch();⑶ +%7yJmMw
conn.commit(); pOyM/L
}catch(Exception e){ Qa5<go{
e.printStackTrace(); 9 @!Og(l
} finally{ LU?X|{z
try{ c`#E#
if(ps!=null) { ]V6<h Psi
ps.clearParameters(); Ib*l{cxN
ps.close(); @8HTC|_vX
ps=null; 5MQD:K2
} !\}Dxt
}catch(SQLException e){} ]~U4;
DBUtils.closeConnection(conn); SWz+.W{KQ"
} e/r41
} UkG|5P`
public long getLast(){ bVQLj}%
return lastExecuteTime; Lf3Ri/@ p
} [~W"$sT
public void run(){ #@;RJJZg
long now = System.currentTimeMillis(); mK%!9F
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if ((now - lastExecuteTime) > executeSep) { R^1sbmwk
//System.out.print("lastExecuteTime:"+lastExecuteTime); [0lCb"
//System.out.print(" now:"+now+"\n"); 'D1
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); N~;=*)_VH
lastExecuteTime=now; ua0`&,a3I
executeUpdate(); !Z
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} - A
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else{ SJ6lI66OX
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); U8c0N<j
} _.' j'j%
} HN7(-ml=B
} hvtg_w6K
//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 6|V713\
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类写好了,下面是在JSP中如下调用。 8do]5FE
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<% 6Hi3h{
CountBean cb=new CountBean(); jJQ6]ucwa
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); "6['!rq0
CountCache.add(cb); I?G
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out.print(CountCache.list.size()+"<br>"); H~i+:X=I
CountControl c=new CountControl(); :2^%^3+V
c.run(); fZ`b~ZBwIj
out.print(CountCache.list.size()+"<br>"); JX7_/P
%>