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: @69q// #B
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CountBean.java T\cdtjk
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/* $6oLiYFX;
* CountData.java bt
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* 9Xm"kVqd/
* Created on 2007年1月1日, 下午4:44 VNytK_F0P
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* To change this template, choose Tools | Options and locate the template under e dD(s5
* the Source Creation and Management node. Right-click the template and choose TS1k'<c?
* Open. You can then make changes to the template in the Source Editor.
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*/ Z)?"pBv'
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package com.tot.count; pCg0xbc`
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/** j
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* 14^t{
* @author o^AK@\e:^Z
*/ \j K?R
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public class CountBean { TkQ05'Qc
private String countType; 3cOXtDV YT
int countId; e| kYu[^
/** Creates a new instance of CountData */ v1)jZ.:
public CountBean() {} :W'1Q2
public void setCountType(String countTypes){ w93yhV?
this.countType=countTypes; DsFrA]
} ^|gN?:fA}
public void setCountId(int countIds){ =CqLZ$10
this.countId=countIds; da2BQ;
} !A<?nz
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public String getCountType(){ g\jdR_/
return countType; !J6k\$r
} Crey}A/N
public int getCountId(){ 'vCFT(C-
return countId; b9\=NdyCY
} lR-4"/1|y
} H ($=k-+5
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CountCache.java 4Q!*h8O
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/* nq$^}L3&~
* CountCache.java I=lA7}
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* Created on 2007年1月1日, 下午5:01 fd)}I23Q'
* R a9/L
* To change this template, choose Tools | Options and locate the template under lual'~
* the Source Creation and Management node. Right-click the template and choose "2Ye\#BU6
* Open. You can then make changes to the template in the Source Editor. D%BV83S
*/ fC81(5
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package com.tot.count; 8cW]jm
import java.util.*; p_mP'
/** UDxfS4yI
* Pu}2%P)p
* @author `[`eg<xj
*/ b9"Q.*c<Z^
public class CountCache { ousoG$Pc
public static LinkedList list=new LinkedList(); EW YpYMkm
/** Creates a new instance of CountCache */ YgVZq\AV"
public CountCache() {} Y%Saz+
public static void add(CountBean cb){ Lo !kv*
if(cb!=null){ CaK 0o*D
list.add(cb); _\u'~wWl
} X}S<MA`
} /)v X|qtIY
} 1 "4AS_Q
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CountControl.java <ZCjQkka>r
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/* %)]{*#N4
* CountThread.java 7MBz&wE^f
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* Created on 2007年1月1日, 下午4:57 $e0sa=/
* AC
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* To change this template, choose Tools | Options and locate the template under t&-7AjS5
* the Source Creation and Management node. Right-click the template and choose [,lBY-Kz+
* Open. You can then make changes to the template in the Source Editor. y5oiH
*/ MF>?! !
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package com.tot.count; [x9eamJ,H
import tot.db.DBUtils; 6R"& !.ZF
import java.sql.*; 6&h,eQ!
/** QDLtilf :
* bY]aADv\
* @author A.(Z0,S-i
*/ m[%&KW(
public class CountControl{ X$J
private static long lastExecuteTime=0;//上次更新时间 d+z8^$z"
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 WG1x:,-
/** Creates a new instance of CountThread */ l? 7D0
public CountControl() {} d)9=hp;,V
public synchronized void executeUpdate(){ o2&mhT
Connection conn=null; 'Kc;~a
PreparedStatement ps=null; ~kF^0-JZY
try{ (AV j_Cw
conn = DBUtils.getConnection();
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conn.setAutoCommit(false); gh3_})8c
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 8BBuYY{
for(int i=0;i<CountCache.list.size();i++){ $FS
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CountBean cb=(CountBean)CountCache.list.getFirst(); ys09W+B7
CountCache.list.removeFirst(); 8*6U4R
ps.setInt(1, cb.getCountId()); T+Du/ERL
ps.executeUpdate();⑴ <Y<%=`
//ps.addBatch();⑵ ".~,(*
} | [P!9e
//int [] counts = ps.executeBatch();⑶ C+jlIT+
conn.commit(); {ge^&l
}catch(Exception e){ O*T(aM3r
e.printStackTrace(); ,D;d#fJ
} finally{ Pe~[qETv
try{ X`#vH8
if(ps!=null) { REc69Y.k
ps.clearParameters(); -PoW56
ps.close(); _-^a8F>/19
ps=null; eY;XF.mF
} UJ
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}catch(SQLException e){} PkMN@JS
DBUtils.closeConnection(conn); `Z0FQ( r_
} sYYNT*
} z'j4^Xz?%$
public long getLast(){ H
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return lastExecuteTime; 9x23## s
} o4\\q66K
public void run(){ yIA-+# r[
long now = System.currentTimeMillis(); 6|| zfH
if ((now - lastExecuteTime) > executeSep) { /*i[MB
//System.out.print("lastExecuteTime:"+lastExecuteTime); ?s6v>#H%
//System.out.print(" now:"+now+"\n"); K>N\U@@8i
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 0EKi?vP@y7
lastExecuteTime=now; k`_sKr]9
executeUpdate(); ;M1# M:
} +9<"Y6
else{ $mgW|TBXCQ
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); mA@FJK_
} ?^n),mR
} T1_O~<
} +<a-;e{
//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 `1{Y9JdQ
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类写好了,下面是在JSP中如下调用。 whxTCI V
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<% Uc^e Ia@
CountBean cb=new CountBean(); )%dxfwd6
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); x+EkL3{
CountCache.add(cb); Je5}Z.3m
out.print(CountCache.list.size()+"<br>"); u5;;s@{Ye4
CountControl c=new CountControl(); k#liYw I
c.run(); O`K2mt\%
out.print(CountCache.list.size()+"<br>"); Gh>&+UA'$1
%>