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: $ly#zQR
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CountBean.java 0,"n-5Im
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/* {LMS~nx
* CountData.java 4acP*LkkQ
* "FLD%3l
* Created on 2007年1月1日, 下午4:44 $,z[XM&9)
* LoV*YSDAY
* To change this template, choose Tools | Options and locate the template under 9 :K
* the Source Creation and Management node. Right-click the template and choose #um1?V
* Open. You can then make changes to the template in the Source Editor. /q*Qx )y+1
*/ Yq)YS]
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package com.tot.count; s$DT.cvO
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/** +aXk^+~j
* Hd=D#u=A4{
* @author @2%VU#!m
*/ t`Y1.]@U
public class CountBean { Lv, ji_
private String countType; H(5ui`' s
int countId; v4,syd*3|V
/** Creates a new instance of CountData */ kw}ISXz v
public CountBean() {} 9Ww=hfb5UW
public void setCountType(String countTypes){ Gg3?2h"d
this.countType=countTypes; ~'Qpf 8)
} ^%4(
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public void setCountId(int countIds){ mNBpb}
this.countId=countIds; x jP" 'yU
} +lDGr/
public String getCountType(){ NBbY## w0
return countType; @tjZvRtZ
} 2os6c te
public int getCountId(){ )z*$`?)k
return countId; +n8I(l=
} 9rf|r
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} )@lo ';\
]'
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CountCache.java 2Xj-A\Oh~
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/* q*<J$PI
* CountCache.java MSYLkQ}_b
* eqUn8<<s
* Created on 2007年1月1日, 下午5:01 0-&sJ
* *"wD&E?
* To change this template, choose Tools | Options and locate the template under f-f\}G&G
* the Source Creation and Management node. Right-click the template and choose }HA2ce\
* Open. You can then make changes to the template in the Source Editor. 43orR !.Z
*/ aP6%OI
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package com.tot.count; 9q0,K" x)
import java.util.*; zOdasEd8!
/** /O(;~1B
* fB @pwmu
* @author 1!v >I"]
*/ 5@%=LPV
public class CountCache { 4~pO>6P
public static LinkedList list=new LinkedList(); ?GMeA}j
/** Creates a new instance of CountCache */ $Zu4tuXA
public CountCache() {} 7PQj7&m
public static void add(CountBean cb){ g)r,q&*
if(cb!=null){ wHN`-
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list.add(cb); onJ[&f
} M'!!EQo
} Velbq
} ,n,7.m.D
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CountControl.java m(7_ZiL=
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/* dv4r\ R^
* CountThread.java (m =u;L"o
* $Bwvw)(%
* Created on 2007年1月1日, 下午4:57 tB(X`A.|
* pQgOT0f
* To change this template, choose Tools | Options and locate the template under 4S{l>/I
* the Source Creation and Management node. Right-click the template and choose ['N#aDh.?
* Open. You can then make changes to the template in the Source Editor. :EldP,s#x%
*/ ,9l!fT?iH
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package com.tot.count; YWBP'Mo
import tot.db.DBUtils; BKP!+V/
import java.sql.*; px(1Ppb9
/** |#khwH
* bl=*3qB
* @author MgK(gL/&[
*/ Dil4ut-$
public class CountControl{ HjF'~n
private static long lastExecuteTime=0;//上次更新时间 NYV0<z@M2M
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 GL0' :LsZ
/** Creates a new instance of CountThread */ C`1\$U~%
public CountControl() {} c,s<q j
public synchronized void executeUpdate(){ GPhwq n{
Connection conn=null; fS$Yl~-m?
PreparedStatement ps=null;
$;`2^L
try{ U -^S<H
conn = DBUtils.getConnection(); P@T $6%~
conn.setAutoCommit(false); 1.OXkgh
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Y<$"]@w
for(int i=0;i<CountCache.list.size();i++){ zZ"')+7q&%
CountBean cb=(CountBean)CountCache.list.getFirst(); wCE fR!i
CountCache.list.removeFirst(); N@`9 ~JS
ps.setInt(1, cb.getCountId()); v_F?x!
ps.executeUpdate();⑴ FVLA^$5c
//ps.addBatch();⑵ x?k |i}Q
} bA9dbe
//int [] counts = ps.executeBatch();⑶ c$Nl-?W
conn.commit(); 8w@jUGsc
}catch(Exception e){ ; >hPHx
e.printStackTrace(); >a]
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} finally{ H-y-7PW*~
try{ I:2jwAl
if(ps!=null) { Q ]koj!mMl
ps.clearParameters(); O7_NXfh|
ps.close(); K]azUK7
ps=null; ^J=txsx
} #(}_2x5
}catch(SQLException e){} ewlc ^`
DBUtils.closeConnection(conn); Q^5 t]HKn
} xx2:5
} WRyv
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public long getLast(){ `fE:5y
return lastExecuteTime; E^>7jf09,
} L$07u{Q
public void run(){ Vblf6qaBs
long now = System.currentTimeMillis(); 5suSR;8
if ((now - lastExecuteTime) > executeSep) { hdDI%3vk3
//System.out.print("lastExecuteTime:"+lastExecuteTime); a+Qj[pS
//System.out.print(" now:"+now+"\n"); ]$k
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); gGz_t,=
lastExecuteTime=now;
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executeUpdate(); !~DkA7i 55
} i*rv_G|(Zj
else{ +( 7vmC.
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); w5G34[v
} vP;tgW9Qk
} j3'/jk]\
} T//+&Sk[
//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 j
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类写好了,下面是在JSP中如下调用。 /u1zRw
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<% W$ {sD|d-
CountBean cb=new CountBean(); wx7>0[ zE
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); KD<`-b)7<
CountCache.add(cb); 5N}|VGN
out.print(CountCache.list.size()+"<br>"); 0
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CountControl c=new CountControl(); TgG)btQ
c.run(); ^O9m11
out.print(CountCache.list.size()+"<br>"); <}>-ip?
%>