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: "$K]+0ryG<
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CountBean.java !TY0;is
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/* z
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* CountData.java S
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* u;1[_~
* Created on 2007年1月1日, 下午4:44 _1Ne+"V
* M2d&7>N
* To change this template, choose Tools | Options and locate the template under $v e$Sq
* the Source Creation and Management node. Right-click the template and choose i[FYR;C
* Open. You can then make changes to the template in the Source Editor. tSoF!@6
*/ KydAFxUb
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package com.tot.count; i;]# @n|
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/** DKem;_6OQ
* kRb JK
* @author p}/D{|xO
*/ aUc#,t;Qd
public class CountBean { "-MB U
private String countType; a|4D6yUw|
int countId; n&|N=zh
/** Creates a new instance of CountData */ L>E{~yh
public CountBean() {} eLXL5&}`fh
public void setCountType(String countTypes){ Lyn{Uag
this.countType=countTypes; Z02EE-A
} UGgo;e
public void setCountId(int countIds){ }2m>S6""A
this.countId=countIds; TqV^\C?
} $dK430_B
public String getCountType(){ 0]MD?6-
return countType; L ed{#+
} `/N={
public int getCountId(){ t:P]bp^#
return countId; .H qJ)OH
} <ME>#,
} &sBD0R(a
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CountCache.java QLHEzEvf{/
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/* =-GxJPL
* CountCache.java {r|RH"|?Z(
* y\-iGKz{0
* Created on 2007年1月1日, 下午5:01 /Ix5`Q)
* ~dLbhjden
* To change this template, choose Tools | Options and locate the template under '|5o(6u'
* the Source Creation and Management node. Right-click the template and choose y x#ub-A8
* Open. You can then make changes to the template in the Source Editor. /%p
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*/ _zzNF93Bn
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package com.tot.count; #=ij</
import java.util.*; 8No'8(dPX
/** <6,,:=#
* h>cjRH?e
* @author gYk5}E-
*/ ;YMg4Cs
public class CountCache { R ;A8y
public static LinkedList list=new LinkedList(); ?P>4H0@I+
/** Creates a new instance of CountCache */ u#^l9/tl
public CountCache() {} k2,`W2]^E
public static void add(CountBean cb){ ,mi7WW9
if(cb!=null){ K4]ZVMm/*
list.add(cb); 5|Z8UzL
} F!/-2u5gF
} O#O"]A
} $ #GuV'
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CountControl.java /0fsn_
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/* DS7L}]
* CountThread.java em )%U
* )flm3G2u
* Created on 2007年1月1日, 下午4:57 U,6sR
* ,`YBTU
* To change this template, choose Tools | Options and locate the template under YN<vOv
* the Source Creation and Management node. Right-click the template and choose 6d/v%-3
* Open. You can then make changes to the template in the Source Editor. ~$j;@4
*/ A<TYt
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package com.tot.count; Y{#*;p*I
import tot.db.DBUtils; +(afO~9
import java.sql.*; $9r4MMs{$
/** L%{YLl-zf]
* kZrc^
* @author } snS~kx
*/ EfpMzD7/(
public class CountControl{ Ij =NcP
private static long lastExecuteTime=0;//上次更新时间 XIZN9/;
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 *o:J 4'
/** Creates a new instance of CountThread */ +_bxza(ma{
public CountControl() {} JEWc{)4QD
public synchronized void executeUpdate(){ j&a\ K}U!
Connection conn=null; @V5i
PreparedStatement ps=null; @H~oOf
try{ [UC_
conn = DBUtils.getConnection(); Iu`S0#+
conn.setAutoCommit(false); g.%} +5
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); s3Zt)xQ3
for(int i=0;i<CountCache.list.size();i++){ cjO%X
CountBean cb=(CountBean)CountCache.list.getFirst(); .sM,U
CountCache.list.removeFirst(); x{K"z4xbI
ps.setInt(1, cb.getCountId()); xJU]py~o
ps.executeUpdate();⑴ *_#2|96)
//ps.addBatch();⑵ M
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} 6\I1J=
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//int [] counts = ps.executeBatch();⑶ 6J}Yr5oD
conn.commit(); 6vps`k$,~
}catch(Exception e){ =>evkaj
e.printStackTrace(); mXS]SE
} finally{ U/cj_}uX
try{ jV%=YapF
if(ps!=null) { ]o0]i<:
ps.clearParameters(); WvfM.D!
ps.close(); cS:O|R#%t
ps=null; UpE+WzY
} !.t D.(XP
}catch(SQLException e){} #-+Q]}fB4
DBUtils.closeConnection(conn); Y3(MKq
} BKb#\(95*
} xDH#K0-#L
public long getLast(){ j3N d4#
return lastExecuteTime; N|>JLZ>
} +Ss3Ph
public void run(){ /BQqg08@L
long now = System.currentTimeMillis(); Umz b
if ((now - lastExecuteTime) > executeSep) { #>,E"-]f
//System.out.print("lastExecuteTime:"+lastExecuteTime); 6aHD?a o
//System.out.print(" now:"+now+"\n"); +/RR!vG,
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); t0@AfO.'1
lastExecuteTime=now; Jp}\@T.
executeUpdate(); Ok{1{EmP
} IpSWg
else{ YwF&-~mp7n
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); yZ)9Hd
} lz<'
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.
} Ev7v,7`z
} (jj`}Qe3U
//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 <Z.{q Zd
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类写好了,下面是在JSP中如下调用。 t1J3'lS
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<% 8Yf*vp>T/x
CountBean cb=new CountBean(); (s&]V49
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); \-[bU6\A\
CountCache.add(cb); }79jyS-e
out.print(CountCache.list.size()+"<br>"); 2\z|/
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CountControl c=new CountControl(); Y_jc *S
c.run(); D|m3.si
out.print(CountCache.list.size()+"<br>"); zaLPPm&f
%>