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: i,r:R
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CountBean.java qsp.`9!
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/* rhbz|Uq
* CountData.java V^n6~O
* 2P^|juc)sU
* Created on 2007年1月1日, 下午4:44 s{Qae=$Q
* h8asj0
* To change this template, choose Tools | Options and locate the template under wpM2{NTP
* the Source Creation and Management node. Right-click the template and choose 6whPW
.
* Open. You can then make changes to the template in the Source Editor. ?iP7Ki
*/ Pgr2S I
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package com.tot.count; MGm*({%
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/** K 77iv
* G-T^1?
* @author * )<+u~
*/ 8F8?1
public class CountBean { o'$"MC+
private String countType; ]6^<VC`5D
int countId; {IJ;)<>&VE
/** Creates a new instance of CountData */ "u7[[.P)
public CountBean() {} GLtd<M"
public void setCountType(String countTypes){ H_$?b
this.countType=countTypes; 8l5>t
} 9y*] {IY
public void setCountId(int countIds){ dYrgL3'
this.countId=countIds; ud`-w
} ]##aAh-P4&
public String getCountType(){ hU""YP~y
return countType; 9KU&M"Yq&i
} /ovVS6Ai
public int getCountId(){ d-_V*rYU
return countId; X?'cl]1?
} +_7a/3kh
} f"FFgQMkv
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CountCache.java (L*GU 7m;
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/* B>L7UQ6_[
* CountCache.java gUru=p
* "5V;~}=S
* Created on 2007年1月1日, 下午5:01 60!%^O =
* _eiqs
* To change this template, choose Tools | Options and locate the template under i7.8H*z'
* the Source Creation and Management node. Right-click the template and choose tRdf:F\X
* Open. You can then make changes to the template in the Source Editor. .U0Gm_c0
*/ X!Z)V)@J8
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package com.tot.count; gPKf8{#%e
import java.util.*; r&
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/** G(a5@9F
* RhE~Rwbx
* @author tr<fii3<
*/ qS+;u`s
public class CountCache { Qjfgxy]
public static LinkedList list=new LinkedList(); eT".psRiC
/** Creates a new instance of CountCache */ K|Sq_/#+U
public CountCache() {} *,$5EN
public static void add(CountBean cb){ >8(i;)(3
if(cb!=null){ 4]U=Y>\Sr
list.add(cb); 754MQK|g
} /9R0}4i7
} M(I%y0
} XvaIOt>A
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CountControl.java
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/* <t"T'\3
* CountThread.java M
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* *<xu3){:c
* Created on 2007年1月1日, 下午4:57 uslu-|b!%
* "@nH;Xlq
* To change this template, choose Tools | Options and locate the template under 4?+K
`
* the Source Creation and Management node. Right-click the template and choose -"I$$C
* Open. You can then make changes to the template in the Source Editor. jhm3:;Z
*/ c#N4XsG,
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package com.tot.count; f(|k0$EIu
import tot.db.DBUtils; d&NnpjH}c
import java.sql.*; ynIC (t
/** Q ]CMm2L^f
* B"&-) (
* @author :8)Jnh\5
*/ K<J,n!zc
public class CountControl{ #BLHHK/[
private static long lastExecuteTime=0;//上次更新时间 AZ3T#f![L@
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 i=Qy?aU?
/** Creates a new instance of CountThread */ '8;bc@cE
public CountControl() {} J 4gtm"2)
public synchronized void executeUpdate(){ uy
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Connection conn=null; { ^dq7!
PreparedStatement ps=null; U4!KO;Jc
try{ xfb .Z(
conn = DBUtils.getConnection(); >.Gmu
conn.setAutoCommit(false); uBRlvNJ
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); _c>ww<*3
for(int i=0;i<CountCache.list.size();i++){ B r#{
CountBean cb=(CountBean)CountCache.list.getFirst(); be8T<F
CountCache.list.removeFirst(); 0/su`
ps.setInt(1, cb.getCountId()); dC({B3#e{
ps.executeUpdate();⑴ qf x*a88
//ps.addBatch();⑵ sGu.G
} PGP#$JC
//int [] counts = ps.executeBatch();⑶ O6G\0o
conn.commit(); KHAc!4lA
}catch(Exception e){ K
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e.printStackTrace(); ;g!rc#z2g
} finally{ dkw.o.e
try{ D0\>E}Y E
if(ps!=null) { <,)R`90_X6
ps.clearParameters(); D -tRy~}
ps.close(); K+}0:W=P
ps=null; V~dhTdQ5}
} [q?RJmB]
}catch(SQLException e){} &4-;;h\H
DBUtils.closeConnection(conn); 8 MO-QO
} #'Y lO-C
} ?9\D(V
public long getLast(){ `>
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return lastExecuteTime; gE6'A
} Jo {:]:
public void run(){ r'*$'QY-N
long now = System.currentTimeMillis(); ?/o 8f7Z
if ((now - lastExecuteTime) > executeSep) { w,p'$WC*
//System.out.print("lastExecuteTime:"+lastExecuteTime); B.; qvuM~
//System.out.print(" now:"+now+"\n"); H'k}/<%Q
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); \n[kzi7
lastExecuteTime=now; VCWW(Y1Fd
executeUpdate(); I<#X#_YP
} $+Ze"E
else{ Lk !)G'42
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); +aOdaNcI
} JVIFpN" `
} L?h?LZnq
} s0iG|vw
//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
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类写好了,下面是在JSP中如下调用。 9f!
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<% -0^]:
CountBean cb=new CountBean(); g=t`3X#d
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); v'i'I/
CountCache.add(cb); KZ%i&w#<
out.print(CountCache.list.size()+"<br>"); |]9@JdmV
CountControl c=new CountControl(); T01Iu
c.run(); OIPY,cj~
out.print(CountCache.list.size()+"<br>"); u!K1K3T6k
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