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: Xs: 3'ua
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CountBean.java ~ab:/!Z
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/* vz.>~HBP
* CountData.java Po%LE]v,
* [sB 9gY(
* Created on 2007年1月1日, 下午4:44 n]E?3UGD@W
* Cj~'Lhmv'T
* To change this template, choose Tools | Options and locate the template under }=c85f~i
* the Source Creation and Management node. Right-click the template and choose {~Rk2:gx
* Open. You can then make changes to the template in the Source Editor. aDO!
*/ ;)N>t\v
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package com.tot.count; '!/<P"5t
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/** 0c} }Q
* Z&;uh_EC
* @author vZ.x{"n'~
*/ [Xb@Wh:yG
public class CountBean { 9eH$XYy
private String countType; uj :%#u
int countId; BNL;Biyt7
/** Creates a new instance of CountData */ H\TI[JPAl
public CountBean() {} g$b<1:8
public void setCountType(String countTypes){ dKdj`wB
this.countType=countTypes; |yx6X{$k
} &mb{.=
public void setCountId(int countIds){ Y "/]|'p
this.countId=countIds; ,7<f9 EVY
} "'D=,*
public String getCountType(){ +HBd
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return countType; +E{|63~q
} s&RVJX>Rt
public int getCountId(){ V4_=<W
return countId; P9T}S
} 6I%5Q4Ll
} U&?v:&c#&n
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CountCache.java EOCN&_Z;
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/* Uu `9"
* CountCache.java Mnscb
* zG(\+4GE!
* Created on 2007年1月1日, 下午5:01 Q)IKOt;N]
*
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* To change this template, choose Tools | Options and locate the template under ZzSz%z_sE
* the Source Creation and Management node. Right-click the template and choose 8uWa=C)
* Open. You can then make changes to the template in the Source Editor. 0tXS3+@n=
*/ ' ~8KSF*!p
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package com.tot.count; abyo4i5T
import java.util.*; NuQdSj_>
/** zzX_q(:S
* b45-:mi!
* @author ~{jcH
*/ "hsb8-
public class CountCache { <i&_ooX
public static LinkedList list=new LinkedList(); ~vyf4TF<#
/** Creates a new instance of CountCache */ ]@phF _
public CountCache() {}
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public static void add(CountBean cb){ |'B7v i)
if(cb!=null){ d>mo~
list.add(cb); * -8&[D0
} Sy0$z39
} R}!:'^
} d'NIV9P`j]
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CountControl.java ui/a|Q
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/* bcE._9@@
* CountThread.java 7t0er'VC
*
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* Created on 2007年1月1日, 下午4:57 1pgU}sRk
* (&F
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* To change this template, choose Tools | Options and locate the template under ZZzMO6US0
* the Source Creation and Management node. Right-click the template and choose pC@{DW;V6R
* Open. You can then make changes to the template in the Source Editor. {#@W)4)cA
*/ "i[@P)
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package com.tot.count; }E50>g
import tot.db.DBUtils; h eV=)8
import java.sql.*; ^LoUi1j
/** 6\q]rfQ
* :%,:"
* @author 6[ j.@[t
*/ n<z[J=I
public class CountControl{ klT@cO-9
private static long lastExecuteTime=0;//上次更新时间
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 %[ Z \S0C
/** Creates a new instance of CountThread */ e?8FN. q
public CountControl() {} $Avjnm
public synchronized void executeUpdate(){ z`f($t[
Connection conn=null; l)1r+@)\
PreparedStatement ps=null; 7o#I,d~
try{ E/|To
conn = DBUtils.getConnection(); l3ko?k
conn.setAutoCommit(false); -z)n?(pftm
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Z8K?
for(int i=0;i<CountCache.list.size();i++){ 42$VhdG
CountBean cb=(CountBean)CountCache.list.getFirst(); -"'j7t:
CountCache.list.removeFirst(); F%@aB<Nu
ps.setInt(1, cb.getCountId()); BBwy,\o#
ps.executeUpdate();⑴
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//ps.addBatch();⑵ gd`!tRcNY
} i@"@9n~
//int [] counts = ps.executeBatch();⑶ M_/7D|xl/T
conn.commit(); QI'Oz{vE
}catch(Exception e){ "K6&dk jY
e.printStackTrace(); iTgt}]L
} finally{ OR~8sU
try{ <lx+/o
if(ps!=null) { &8Cu#^3
ps.clearParameters(); mwHB(7YS,
ps.close(); $P^q!H4D
ps=null; S2sQOM@
} N4F.Y"R$(
}catch(SQLException e){} 6xTuNE1
DBUtils.closeConnection(conn); MyJ%`@+1
} {?}E^5Z*g
} 0zmE>/O+
public long getLast(){ r1 !@hT
return lastExecuteTime; `yrB->|vG
} xr4*{v
public void run(){ 6t[+pL\b
long now = System.currentTimeMillis(); 7)`nD<j5
if ((now - lastExecuteTime) > executeSep) {
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//System.out.print("lastExecuteTime:"+lastExecuteTime); Lo{
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//System.out.print(" now:"+now+"\n"); G|!Tj X7s
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); |"ls\ 7
lastExecuteTime=now; Yvw(tj5_5
executeUpdate(); ayR-\mZ
} &^ 1$^=
else{ ,8U&?8l
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); snE8 K}4
} [=6]+V83M
} y\4L{GlBM
} )~)J?l3{
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 *2pt%eav
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类写好了,下面是在JSP中如下调用。 [B\h$IcRv
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<% fphv
CountBean cb=new CountBean(); #+Ir>GU
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); #L=x%8B
CountCache.add(cb); e$<0
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out.print(CountCache.list.size()+"<br>"); bh,[ 3X%
CountControl c=new CountControl(); 4tRYw0f47
c.run(); k]F[>26k
out.print(CountCache.list.size()+"<br>"); t3 8m'J :>
%>