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: <7~'; K
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CountBean.java a|X a3E
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/* 4t=G
* CountData.java
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* B6={&7U2
* Created on 2007年1月1日, 下午4:44 u A<n
* ez|)ph7
* To change this template, choose Tools | Options and locate the template under W)bLSL]`E
* the Source Creation and Management node. Right-click the template and choose `EaLGzw
* Open. You can then make changes to the template in the Source Editor. }~L.qG
*/ {tWf
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package com.tot.count; ~A\GT$
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/** F%RRd/'
* |!4K!_y
* @author o4Om}]Ti
*/ c24dSNJg,
public class CountBean { ln6d<;
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private String countType; g%=z_
int countId; I`!<9OTBj
/** Creates a new instance of CountData */ DW[N|-L
public CountBean() {} ~nay" g:
public void setCountType(String countTypes){ lNYt`xp
this.countType=countTypes; JJN.ugT}1
} M<v%CawS
public void setCountId(int countIds){ t7aefV&_,
this.countId=countIds; :/nj@X6
} cPlZXf
public String getCountType(){ ]Gsv0Xk1
return countType;
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} fumm<:<CLO
public int getCountId(){ U2W|:~KM
return countId; SHfy".A6.0
} C&(N
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} Tw-;7Ae
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CountCache.java gtppv6<Mj4
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/* asppRL||
* CountCache.java 8.O8No:'&
* I=`U7Bis"
* Created on 2007年1月1日, 下午5:01 V@g'#={r
* cQ
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* To change this template, choose Tools | Options and locate the template under ]>5/PD,wWy
* the Source Creation and Management node. Right-click the template and choose 5Odhb
* Open. You can then make changes to the template in the Source Editor. vg32y /l]S
*/ rC^WPW
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package com.tot.count; zBzZxK>$
import java.util.*; Q' {ML4
/** n-tgX?1'
* zHM(!\8K
* @author ~qTx|",
*/ UM"- nZ>[
public class CountCache { 6a~|K-a6
public static LinkedList list=new LinkedList(); +nFu|qM}
/** Creates a new instance of CountCache */ W{ q U
public CountCache() {} !Wntd\w
public static void add(CountBean cb){ n{argI8wF
if(cb!=null){ -&zZtDd F
list.add(cb); rlOAo`hd
} Rl?_^dPx
} f.KN-f8<F
} YJT&{jYi
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CountControl.java iP ->S\
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/* "#2a8#
* CountThread.java n FHUy9q
* ^ B fC
* Created on 2007年1月1日, 下午4:57 )q8p k2
* K0|FY=#2y
* To change this template, choose Tools | Options and locate the template under W}@c|d $`
* the Source Creation and Management node. Right-click the template and choose aC8} d
* Open. You can then make changes to the template in the Source Editor. 65JF`]
*/ 0z6R'Kjy A
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package com.tot.count; 8Fz#A.%P
import tot.db.DBUtils; z]_wjYn Z
import java.sql.*; 7x|9n
/** UD2C>1j
*
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* @author B9jC?I |`
*/ vc;$-v$&
public class CountControl{ KQ!8ks]
private static long lastExecuteTime=0;//上次更新时间 )Q&(f/LT
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 rr],DGg+B]
/** Creates a new instance of CountThread */ /~%&vpF-L
public CountControl() {} 6H.0vN&
public synchronized void executeUpdate(){ hF~n)oQ
Connection conn=null; `ts$(u.w
PreparedStatement ps=null; k8&;lgO'
try{ k<CJ{u0<
conn = DBUtils.getConnection(); 7rc0yB
conn.setAutoCommit(false); X9W@&zQ
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); X!TpYUZ'
for(int i=0;i<CountCache.list.size();i++){ Tztu}t]N
CountBean cb=(CountBean)CountCache.list.getFirst(); [
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CountCache.list.removeFirst(); ;u_X)
ps.setInt(1, cb.getCountId()); l*Gvf_UH
ps.executeUpdate();⑴ @zW]2 c
//ps.addBatch();⑵ K7_UP&`=J
} BU/"rv"(Fg
//int [] counts = ps.executeBatch();⑶ ohGJ1
conn.commit(); _7Ju
}catch(Exception e){ 4yy>jXDG
e.printStackTrace(); dd %6t
} finally{ P9^Xm6QO
try{ e5ZX
if(ps!=null) { 24 ' J
ps.clearParameters(); EIP/V
ps.close(); %HhnSi1K
ps=null; \h/H#jZJ
} )0]'QLH
}catch(SQLException e){} M6"PX *K
DBUtils.closeConnection(conn); S%;O+eFYb
} i
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} iy.p n
public long getLast(){ @alK;\
return lastExecuteTime; zZPO&akB"
} _}Ac n$
public void run(){ =7=]{Cx[
long now = System.currentTimeMillis(); oq
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if ((now - lastExecuteTime) > executeSep) { 5uGq%(24
//System.out.print("lastExecuteTime:"+lastExecuteTime); nfbR
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//System.out.print(" now:"+now+"\n"); GY'%+\*tj
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); #jvtUS \
lastExecuteTime=now; hR?{3d#x2
executeUpdate(); Mq156TL
} hn
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else{ PJ|P1O36a
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); m e$Z~/Akm
} AlaW=leTe
} 5{X<y#vAC0
} {UI+$/v#
//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 y%cP1y)
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类写好了,下面是在JSP中如下调用。 g
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<% UcHJR"M~c
CountBean cb=new CountBean(); Rsm^Z!sn
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Vx u0F]%
CountCache.add(cb); tCH!my_
out.print(CountCache.list.size()+"<br>"); rpha!h>w1%
CountControl c=new CountControl(); q"lSZ;
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c.run(); -=Q*Ml#I
out.print(CountCache.list.size()+"<br>"); ~!d\^Z^i
%>