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: w&9F>`VET
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CountBean.java wH!}qz/
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/* ID+,[TM`
* CountData.java epYj+T
* +O,V6XRr
* Created on 2007年1月1日, 下午4:44 Ho>p ^p
* 03] r*\
* To change this template, choose Tools | Options and locate the template under x6jm-n
* the Source Creation and Management node. Right-click the template and choose DWdLA~'t
* Open. You can then make changes to the template in the Source Editor. ym[+Rw
*/ ,A^L=+
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package com.tot.count; [(!Q-8
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/** z3ZuC{
* M$#+W?m&
* @author HoMQt3C
*/ Qk|( EFQ9
public class CountBean { ?3n=m%W,J*
private String countType; tI
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int countId; Re7{[*Q4
/** Creates a new instance of CountData */ +6uOg,;
public CountBean() {} 7/4~>D&-b
public void setCountType(String countTypes){ RlPjki"Mg
this.countType=countTypes; l(.7t'
} :S#eg1y.w]
public void setCountId(int countIds){ FV`3,NFk
this.countId=countIds; +Z )`inw
} ?Z5$0-g'hU
public String getCountType(){ uAC hu]
return countType; MG;4M>H
} J&(
public int getCountId(){ p$B)^S%0i
return countId; ws#hhW3qK
} 9'D8[p%
} 0H;"5
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CountCache.java oJhEHx[f
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/* _Wq7U1v`
* CountCache.java }'%$7vL`Ft
* UnJi& ~O
* Created on 2007年1月1日, 下午5:01 Ua}g
* //VG1@vaVX
* To change this template, choose Tools | Options and locate the template under LPsh?Ca?N
* the Source Creation and Management node. Right-click the template and choose %L.lkRs
* Open. You can then make changes to the template in the Source Editor. Pxap;;\
*/ R%Kl&c
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package com.tot.count; FLw[Mg:L
import java.util.*; AsV8k_qZL
/** [ e$]pN%
* Ty)gPh6O
* @author :Xb*m85y
*/ :/ ~):tM
public class CountCache { v\J!yz
public static LinkedList list=new LinkedList(); o,iS&U"TC
/** Creates a new instance of CountCache */ 4&#vU(-H
public CountCache() {} R9S7_u
public static void add(CountBean cb){ N)`tI0/W
if(cb!=null){ x*3@,GmZl
list.add(cb); ]%b0[7[
} ?U7&R%Lh`
} FuIWiO(
} pIk4V/fy
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CountControl.java f:)]FHPB1
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/* 0;.e#(`-
* CountThread.java 1t!&xvhG
* [RroHXdk+
* Created on 2007年1月1日, 下午4:57 h}Fu"zK
* :0i#=ODR
* To change this template, choose Tools | Options and locate the template under C6Um6X9/i
* the Source Creation and Management node. Right-click the template and choose ZS07_6.~
* Open. You can then make changes to the template in the Source Editor. @`#OC#
*/ Q&\ZC?y4
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package com.tot.count; &Z#Vw.7U
import tot.db.DBUtils; Yqq$kln
import java.sql.*; :/I={)5
/** T#ecLD#
* 2d,wrC<'$
* @author mE)x7
*/ M$DwQ}Z
public class CountControl{ 1KfJl S+
private static long lastExecuteTime=0;//上次更新时间 -Hl\j(D7
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 pZNlcB[Qn-
/** Creates a new instance of CountThread */ P7M0Ce~iW
public CountControl() {} KyVe0>{_u
public synchronized void executeUpdate(){ &@Ji+
Connection conn=null; 'eTpcrS3
PreparedStatement ps=null; 6EW"8RG`
try{ 4c493QOd
conn = DBUtils.getConnection(); ulJ+:zwq$
conn.setAutoCommit(false); /
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ZVCv(J
for(int i=0;i<CountCache.list.size();i++){ y0W`E/1t
CountBean cb=(CountBean)CountCache.list.getFirst(); ?Vb=4B{~
CountCache.list.removeFirst(); ^ ^U)WB
ps.setInt(1, cb.getCountId()); D(W7O>5vQ2
ps.executeUpdate();⑴ YQlpk@X`2
//ps.addBatch();⑵ )[a?J,
} M$E8:
//int [] counts = ps.executeBatch();⑶ *;~{_Disz
conn.commit(); ^+YGSg7
}catch(Exception e){ ^+.e5roBKj
e.printStackTrace(); yDl5t-0`
} finally{ av$\@4I
try{ #dXZA>b9
if(ps!=null) { ?L.p9o-S0
ps.clearParameters(); vCrWA-q#
ps.close(); vM$#m1L?
ps=null; Xqq?S
} 2n\i0?RD
}catch(SQLException e){} J@&$U7t
DBUtils.closeConnection(conn); **
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} \n( 'KVbf
} M\x7=*\
public long getLast(){ lVO(9sl*i
return lastExecuteTime; G+%5V5GS
} FZLzu
public void run(){ G/^5P5y%@
long now = System.currentTimeMillis(); 'SXpb?CZ
if ((now - lastExecuteTime) > executeSep) { "1\RdTw
//System.out.print("lastExecuteTime:"+lastExecuteTime); /-cX(z
7
//System.out.print(" now:"+now+"\n"); t2U]CI%
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); *PA1iNdKS
lastExecuteTime=now; o7Z#,>`2
executeUpdate(); x<j($iv
} 5 }(YMsUb
else{ 9fk\Ay1P
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); knj,[7uh
} R _~m\P
} YQw/[
} LP-KD
//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 KfN`ZZ<
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类写好了,下面是在JSP中如下调用。
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<% +P<w<GfQ
CountBean cb=new CountBean(); N*c?Er@8U
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); oBGst t@
CountCache.add(cb); *~MiL9m+?
out.print(CountCache.list.size()+"<br>"); X_Of k
CountControl c=new CountControl(); M@z_Z+q9
c.run(); fuwp p
out.print(CountCache.list.size()+"<br>"); ag*Hs<gi
%>