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: fT0+inRG
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CountBean.java mu@IcIb>
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/* J9q[u[QZ9O
* CountData.java n7iIY4gZ
* VY j
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* Created on 2007年1月1日, 下午4:44 Ct9dV7SH
* {LqahO*
* To change this template, choose Tools | Options and locate the template under ?h3t"9
* the Source Creation and Management node. Right-click the template and choose 9e0t
* Open. You can then make changes to the template in the Source Editor. 63T4''bwu
*/ 3u&)6C?YM
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package com.tot.count; de,4Ms!%
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/** ;C~:C^Q\H
* MOIMW+n
* @author 1aS66TS3
*/ Vy@0Got5=
public class CountBean { W7?f_E\>W
private String countType; 3GM9ZPeN:
int countId; Km!~zG7<
/** Creates a new instance of CountData */ NzG] nsw
public CountBean() {} 6'ia^om
public void setCountType(String countTypes){ Ae^Idz
this.countType=countTypes; P"<,@Mn
} f#|
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public void setCountId(int countIds){ %Z{ 7*jtE
this.countId=countIds; i1DJ0xC]
} A ?ij
public String getCountType(){ !"s~dL,7
return countType; D |9ItxYu
} u8b^DB#+W
public int getCountId(){ ~zyD=jxP9
return countId; V@`A:Nc_>
} ?~WDlj3
} QRlrcauM
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CountCache.java 3;f}w g
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/* 9y`Vg
* CountCache.java CkEbSa<)hK
* JXk<t5@D
* Created on 2007年1月1日, 下午5:01 lvk
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* fe+2U|y
* To change this template, choose Tools | Options and locate the template under e3}o3c_
* the Source Creation and Management node. Right-click the template and choose m!^z{S
* Open. You can then make changes to the template in the Source Editor. qExmf%q:q
*/ q#*b4q
{
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package com.tot.count; epQdj=h
import java.util.*; '<% ;Nv
/** $uCY\xqZ
* Nj$h/P
* @author >NAg*1
*/ /4Jm]"
public class CountCache { f~v@;/HL
public static LinkedList list=new LinkedList(); nW!pOTJq21
/** Creates a new instance of CountCache */ +=g9T`YbE
public CountCache() {} (VB-5&b
public static void add(CountBean cb){ NG\^>.8
if(cb!=null){ Iv51,0A
list.add(cb); H*vd
} Cbjx{
} ??h4qJ
} WQ)vu&;
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CountControl.java q+cx.Rc#
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/* *;Gn od<
* CountThread.java V8+8?5'l
* wfrSI:+>
* Created on 2007年1月1日, 下午4:57 Z Ne(sg~G
* o 12wp
* To change this template, choose Tools | Options and locate the template under aT20FEZ;
* the Source Creation and Management node. Right-click the template and choose ;}QM#5Xdt
* Open. You can then make changes to the template in the Source Editor. ZmzYJ$:6
*/ hVdPO
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package com.tot.count; `;v>fTcy
import tot.db.DBUtils; J6J|&Z~UT,
import java.sql.*; 48"=,IrM
/** {B)-+0 6
* ;/)u/[KAv
* @author
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*/ y3Lq"?h
public class CountControl{ @;g|styh^
private static long lastExecuteTime=0;//上次更新时间 3FhkK/@
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 'D17]Lp~.
/** Creates a new instance of CountThread */ UY`U[#
public CountControl() {} N]7#Q.(~
public synchronized void executeUpdate(){ 0uwe,;
Connection conn=null; Y0ouLUlI
PreparedStatement ps=null; \p{$9e;8yT
try{ ^>tqg^
conn = DBUtils.getConnection(); boWaH}?0'
conn.setAutoCommit(false); ~pve;(e=
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 5MmSQ_
for(int i=0;i<CountCache.list.size();i++){ dBM> ;S;v
CountBean cb=(CountBean)CountCache.list.getFirst(); `cn}}1Lg]
CountCache.list.removeFirst(); J>%uak<
ps.setInt(1, cb.getCountId()); )R5=GHmL
ps.executeUpdate();⑴ _~a5;[~
//ps.addBatch();⑵ '1[Bbs
} /d
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//int [] counts = ps.executeBatch();⑶ Z!SFJ{
conn.commit(); :+$/B N:iO
}catch(Exception e){ L6IF0`M<,I
e.printStackTrace(); eO?@K$I
} finally{ X+;{&Efrl
try{ ^rIe"Kx
if(ps!=null) { w;8VD`>[|
ps.clearParameters();
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ps.close(); wh)Ujgd
ps=null; 4Up\_
} !Ng~;2GoA
}catch(SQLException e){} HYWKx><
DBUtils.closeConnection(conn);
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} +?R!
} =b[q<p\
public long getLast(){ Df_*W"(v
return lastExecuteTime; oH]"F
} 3*;S%1C^
public void run(){ |8s45g>
long now = System.currentTimeMillis(); DqbU$jt`
if ((now - lastExecuteTime) > executeSep) { +y\mlfJ.-b
//System.out.print("lastExecuteTime:"+lastExecuteTime); Y.}8lh
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//System.out.print(" now:"+now+"\n"); i\94e{uty[
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); &I=F4 z
lastExecuteTime=now; m*
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executeUpdate(); -na oM
} 'Nn>W5#))
else{ n1
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); YDoVm?
} hB 36o9|9
} OF/DI)j3
} mjXO}q7
//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 [lbe_G;
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类写好了,下面是在JSP中如下调用。 M<VZISu)dy
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<% %X>P+6<=
CountBean cb=new CountBean(); })^%>yLfc|
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); |6y(7Ha
CountCache.add(cb); :rhh=nHgn
out.print(CountCache.list.size()+"<br>"); cO^}A(Ma(
CountControl c=new CountControl(); 2pn8PQfg)
c.run(); vivU4:uH3
out.print(CountCache.list.size()+"<br>"); />[X
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%>