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: C
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CountBean.java lE`ScYG
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/* {6KU.'#iF
* CountData.java 5 i#B?+Y
* c8yD-U/-
* Created on 2007年1月1日, 下午4:44 P EbB0GL
* KL|B| u
* To change this template, choose Tools | Options and locate the template under sX=!o})0
* the Source Creation and Management node. Right-click the template and choose CtE".UlCA
* Open. You can then make changes to the template in the Source Editor. zL_X?UmV
*/ d~n+Ds)%F
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package com.tot.count; Pjx9@i
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/** 4RzG3CJdS
* sC}/?^q
* @author -OziUM1qs
*/ fZGKVxo"
public class CountBean { fG.w;Aemv5
private String countType; S#""((U$
int countId; CsE|pXVG
/** Creates a new instance of CountData */ HPgMVp'
public CountBean() {} WUxr@0
public void setCountType(String countTypes){ -7yX>Hjl
this.countType=countTypes; <fyv^e
} tG{Vn +~/
public void setCountId(int countIds){ 36j.is
this.countId=countIds; QzS{2Y[OQ
} co*5NM^
public String getCountType(){ V*/))n?
return countType; k%LE"Q
} ?r@ZTuq#
public int getCountId(){ mhs%b4'>
return countId; T^Z#x-Q
} !KF;Z|_(I
} -Zw"o>
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CountCache.java F4PD3E_#
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/* M0]fh5O
* CountCache.java 11)~!in
* vi=yR
* Created on 2007年1月1日, 下午5:01 IAtZ-cM<
* H;Bj\-Pa
* To change this template, choose Tools | Options and locate the template under bM!`C|,[s
* the Source Creation and Management node. Right-click the template and choose |l~ADEg
* Open. You can then make changes to the template in the Source Editor. !O.B,
*/ 9R E;50h
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package com.tot.count; BujWql
import java.util.*; lmd0Q(I
/**
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* 1n5&PNu
* @author 4@VX%5uy
*/ [F>zM
public class CountCache { n%O`K{86
public static LinkedList list=new LinkedList(); ^X?[zc GE
/** Creates a new instance of CountCache */ ;Joo!CXHO
public CountCache() {} D2hvf^g'*
public static void add(CountBean cb){ M,[ClQ 9
if(cb!=null){ dNyc|P`U
list.add(cb); !cq4+0{O;&
} Sj*H4ZHD<&
} < ^&'r5H
} sO*6F`eiZ
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CountControl.java Wqqo8Y~fq
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/* =GpLlJ`-
* CountThread.java PK~okz4b
* EYQ!ELuF
* Created on 2007年1月1日, 下午4:57 mEqV&M1;7l
* dxd}:L~z
* To change this template, choose Tools | Options and locate the template under y3xP~]n
* the Source Creation and Management node. Right-click the template and choose xq]&XlA:ug
* Open. You can then make changes to the template in the Source Editor. ZBYmAD
*/ 712i|
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package com.tot.count; ~q9RZ#g13J
import tot.db.DBUtils; 4gZN~_AI<
import java.sql.*; D QRt\!
/** 'R$~U?i8
* 0q3:"X
* @author <9Chkb|B
*/ Ne4A
public class CountControl{ ^.4<#Qs
private static long lastExecuteTime=0;//上次更新时间 NfSe(rd
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 NT nn!k
/** Creates a new instance of CountThread */ ZqhINM*Rm
public CountControl() {} k82'gJ;MC=
public synchronized void executeUpdate(){ n2QD*3i
Connection conn=null; >SzTZ3!E
PreparedStatement ps=null; '.bMkty#
try{ ^=@%@mR/[C
conn = DBUtils.getConnection(); wg[*]_,a
conn.setAutoCommit(false); dzcPSbbpt
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); '3xSzsDn
for(int i=0;i<CountCache.list.size();i++){ x^
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CountBean cb=(CountBean)CountCache.list.getFirst(); ,p2
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CountCache.list.removeFirst(); duM>(y
ps.setInt(1, cb.getCountId()); ,5/gNg
ps.executeUpdate();⑴ \gzNMI*
//ps.addBatch();⑵ g_q{3PW.
} t]m#k%)
//int [] counts = ps.executeBatch();⑶ \0:l9;^4
conn.commit(); `aUA_"f
}catch(Exception e){ 5yQgGd)
e.printStackTrace(); M"J$c42
} finally{ bySw#h_
try{ 8Ej2JMc
if(ps!=null) { p&q&Fr-
ps.clearParameters(); )PwDP
ps.close(); BvYJ!Vj
ps=null; 3Y8%5/D5
} yb]a p
}catch(SQLException e){} c2i^dNp_
DBUtils.closeConnection(conn); QTDI^ZeuF
} @Wv*`
} ' E@D
public long getLast(){ AvwX 2?tc
return lastExecuteTime; T|=8jt,
} E;X'.7[c
public void run(){ 's9)\LS>p
long now = System.currentTimeMillis(); sPhh#VCw{
if ((now - lastExecuteTime) > executeSep) { xOt|j4
//System.out.print("lastExecuteTime:"+lastExecuteTime); Q[k}_1sWs$
//System.out.print(" now:"+now+"\n"); r+U-l#Q
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); KUp
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lastExecuteTime=now; K4
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executeUpdate(); ?2i``-|Wa
} s5[ Cr"q7B
else{
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); s*Fmu7o43
} 2yN~[,L
} 68D.Li
} <?I~ +
//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 1M+mH#?
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类写好了,下面是在JSP中如下调用。 m!PN1$9V
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<% FPu,sz8
CountBean cb=new CountBean(); \:Nbl<9(9
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); [3\}Ca1
CountCache.add(cb); ul:jn]S*
out.print(CountCache.list.size()+"<br>"); NQOdgp
CountControl c=new CountControl(); ^
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c.run(); 5ecqJ
out.print(CountCache.list.size()+"<br>"); uh GL1{
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