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: l&'q+F
[H>u'fy:C
CountBean.java a%`%("g!
}$'_%,
/* E5M/XW\E6
* CountData.java C&MqH.K
* dS4z Oz"
* Created on 2007年1月1日, 下午4:44 )H{1Xjh-
* /bB4ec8!
* To change this template, choose Tools | Options and locate the template under KvPCb%!ZP
* the Source Creation and Management node. Right-click the template and choose 9Ffam#
* Open. You can then make changes to the template in the Source Editor. zIjfxK
*/ tm^joK[{|J
'ET];iZ2
package com.tot.count; o,dp{+({
9&AO
/** ,)#rD9ZnC
* MK)}zjw
* @author ~ILv*v@m
*/ >19s:+
public class CountBean { \\#D!q*
private String countType; UGy3B)
int countId; to</
/** Creates a new instance of CountData */ ,.>9$( s
public CountBean() {} h%ys::\zF
public void setCountType(String countTypes){ WcNQF!f
this.countType=countTypes; dB0#EJaE
} PENB5+1OK
public void setCountId(int countIds){ !V3+(o1
this.countId=countIds; :VZS7$5
} t~/:St
public String getCountType(){ cOX )+53
return countType; pF-_yyQ
} sIgTSdk
public int getCountId(){ ]B=*p0~j^n
return countId; T:X*
} O& Sk}^
} $jE<n/8
EOXkMr
CountCache.java
<KU0K
hQm=9gS
/* 0't)-Pj+,
* CountCache.java [07E-TT2U
* Jcze.t
* Created on 2007年1月1日, 下午5:01 XNJZ~Mowb
* N'WTIM3W
* To change this template, choose Tools | Options and locate the template under vHcl7=)Q
* the Source Creation and Management node. Right-click the template and choose `D~oY=
* Open. You can then make changes to the template in the Source Editor. l_Lz9k
*/ Y$v #>w_M
jeRE(3'Q
package com.tot.count; p7;K] AW
import java.util.*; @gK`RmhGE5
/** D!,5j_,j%
* K}re{y
* @author |kPgXq6
*/ JR.)CzC
public class CountCache { -(:T&rfTp
public static LinkedList list=new LinkedList(); v.Bwg7R3
/** Creates a new instance of CountCache */ A&t8C8,
public CountCache() {} HJ7A/XW
public static void add(CountBean cb){ 8$_{R!x
if(cb!=null){ <1*.:CL"s
list.add(cb); DPxx9lN_rx
} ;7:} iKU
} 7CH&n4v
} KJec/qca
}'eef"DJ9
CountControl.java a~0 ~Y y
FXJ0
G>F
/* l+"p$iZs
* CountThread.java 5_E8
RAG
* @u9L+*F
* Created on 2007年1月1日, 下午4:57 ?5nEmG|kO
* [S,$E6&j$"
* To change this template, choose Tools | Options and locate the template under HZRFE[ 9nb
* the Source Creation and Management node. Right-click the template and choose L?N&kzA
* Open. You can then make changes to the template in the Source Editor. aj;x:UqpJ
*/ MSS[-}
?YL JXq
package com.tot.count; F8-GnTxa
import tot.db.DBUtils; SED52$zA
import java.sql.*; q *&H
/** c8X;4
My
* ]j>xQm\
* @author oqF?9<Vgc,
*/ k37?NoT
public class CountControl{ 1!MJ+?Jl
private static long lastExecuteTime=0;//上次更新时间 ';FJs&=I
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 >o1dc*
/** Creates a new instance of CountThread */ @`L;_S+
public CountControl() {} V*\hGNV
public synchronized void executeUpdate(){ q"2APvsvp
Connection conn=null; 1cOR?=G~
PreparedStatement ps=null; jSE)&K4nI
try{ $lT8M-yK\
conn = DBUtils.getConnection(); 2.%)OC!q&5
conn.setAutoCommit(false); gxVr1DIkN
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); $uTrM8
for(int i=0;i<CountCache.list.size();i++){ q1:dcxR[
CountBean cb=(CountBean)CountCache.list.getFirst(); zb9G&'7
CountCache.list.removeFirst(); lg-_[!4Z
ps.setInt(1, cb.getCountId()); _S
ng55s
ps.executeUpdate();⑴ >va_,Y}
//ps.addBatch();⑵ =fRS UtX
} aJ(/r.1G
//int [] counts = ps.executeBatch();⑶ 9lYfII}4(
conn.commit(); 0"OEOYs}
}catch(Exception e){ Qpmq@iL
e.printStackTrace(); ny13+Q`^
} finally{ .S54:vs
try{ u:p OP
if(ps!=null) { m*_X PY
ps.clearParameters(); rah"\f2
ps.close(); #E!^oZm<Z
ps=null; #b[bgxm
} ,.9 lz
}catch(SQLException e){} VNWB$mM.2
DBUtils.closeConnection(conn); JGHj(0j
} C7{VByxJ
} SDC|>e9i
public long getLast(){ t7-]OY7%w_
return lastExecuteTime; >1!u]R<3
} G%bv<_R
public void run(){ J "I,]
long now = System.currentTimeMillis(); ?P0b/g
if ((now - lastExecuteTime) > executeSep) { #b;?:.m\=
//System.out.print("lastExecuteTime:"+lastExecuteTime); zz
U,0
L
//System.out.print(" now:"+now+"\n"); g0zzDv7~
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Mrrpm%Y
lastExecuteTime=now; sr;&/l#7h
executeUpdate(); oIick
} BQPmo1B
else{ !2!Zhw2u
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 5]dlD #
} \"ahs7ABT
} `qhT
} 0}<blU
//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<(E%KN3
{`SMxDevc}
类写好了,下面是在JSP中如下调用。 :
b`N(]
&q<k0_5Q
<% Nksm&{=6S
CountBean cb=new CountBean(); ]6Iu\,#J
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ,VVA^'+
CountCache.add(cb); hb;CpA
out.print(CountCache.list.size()+"<br>"); myfTztJ
CountControl c=new CountControl(); ( 5!'42
c.run(); DehjV6t
out.print(CountCache.list.size()+"<br>"); nIg 88*6b,
%>