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: #;9H@:N
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CountBean.java #/J
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/* !MZw#=D`
* CountData.java Dxx;v .$
* 90 {tI X
* Created on 2007年1月1日, 下午4:44 _[Gb)/@mM
* V:K;] h*!
* To change this template, choose Tools | Options and locate the template under <SXZx9A!
* the Source Creation and Management node. Right-click the template and choose H^c0Kh+
* Open. You can then make changes to the template in the Source Editor. jThbeY[
*/ dK?);*w]
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package com.tot.count; = (U/CI
" mj^+u-
/** Q49BU@xX
* H~+xB1
* @author +!>LY
*/ \tt'm\_
public class CountBean { a#(U2OP
private String countType; P15:,9D
int countId; !c8L[/L
/** Creates a new instance of CountData */ ;"7/@&M\m
public CountBean() {} i*tv,f.(
public void setCountType(String countTypes){ =:$) Z
this.countType=countTypes; 0%Q9}l#7
} aPIr_7e
public void setCountId(int countIds){ wz#[:2
this.countId=countIds; n
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} lJ/6-dP
public String getCountType(){ u*R7zY
return countType; VyZV(k
} R$0U<(/
public int getCountId(){ =:K@zlO:
return countId; g{ (@uzqG
} mx tgb$*
} c>MY$-PD
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CountCache.java o<\6Rm
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/* >}]H;&
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* CountCache.java sco
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* K`+vfqX
* Created on 2007年1月1日, 下午5:01 2ij/N%l
* D0%FELG05
* To change this template, choose Tools | Options and locate the template under mTd<2Hy
* the Source Creation and Management node. Right-click the template and choose x-~-nn\O
* Open. You can then make changes to the template in the Source Editor. Z[;#|$J
*/ Yk7"XP[Y
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package com.tot.count; j;0ih_Z@4W
import java.util.*;
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/** aJQXJ,>Lv
* \9jpCNdJ
* @author 24|<<Xn
*/ sA2o2~AmM
public class CountCache { =tq7z =k
public static LinkedList list=new LinkedList(); R<j<.h
/** Creates a new instance of CountCache */ G-8n
public CountCache() {} p2a?9R
public static void add(CountBean cb){ 7j R7
if(cb!=null){ @ V5S4E
list.add(cb); Nh :JU?h
} G;9|%yvd8
} %
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} }wG|%Y#+r
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CountControl.java aKOf;^@
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/* 3Pa3f >}-
* CountThread.java v['AB4
* _X?y,#
* Created on 2007年1月1日, 下午4:57 * S{\#s
* *|CLO|B)
* To change this template, choose Tools | Options and locate the template under =%)})
* the Source Creation and Management node. Right-click the template and choose q4zSS #]A
* Open. You can then make changes to the template in the Source Editor. (Z'WR
*/ dc)wu]
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package com.tot.count; "1CGO@AXS
import tot.db.DBUtils; O{*GW0}55
import java.sql.*; D~7%};D[
/** d^_itC;-,
* @u<0_r
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* @author +:b(%|
*/ JH-nvv
public class CountControl{ P)4x
private static long lastExecuteTime=0;//上次更新时间 Z!k5"\{0pE
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 XZ;*>(
/** Creates a new instance of CountThread */ vN'VDvVM
public CountControl() {} 0.3^
public synchronized void executeUpdate(){ w# xncH:1
Connection conn=null; e|35|I '
PreparedStatement ps=null; nJW_a&'
try{ :R{x]sv
conn = DBUtils.getConnection(); }isCvb
conn.setAutoCommit(false); $)4GCP
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); G)4ZK#wz
for(int i=0;i<CountCache.list.size();i++){ vRq=m8
CountBean cb=(CountBean)CountCache.list.getFirst(); CuF%[9[cT
CountCache.list.removeFirst(); r=xTs,xx
ps.setInt(1, cb.getCountId()); cYE./1D a
ps.executeUpdate();⑴ ^7J~W'hI
//ps.addBatch();⑵ \=$EmHF
} t@l(xns V
//int [] counts = ps.executeBatch();⑶ (ej:_w1
conn.commit(); 6yy|V~5
}catch(Exception e){ ,s\x]bh
e.printStackTrace(); ab8oMi`z
} finally{ M9g~lKs'
try{ n.=e)*
if(ps!=null) { f%`*ba"v
ps.clearParameters(); 3w[<cq.!
ps.close(); Q:'qw#P/C
ps=null; )er?*^9Z
} ^aGZJiyJ
}catch(SQLException e){} G5y]^P
DBUtils.closeConnection(conn); d08`42Z69
} '-$))AdD
} rC* sNy2
public long getLast(){ BnKP7e
return lastExecuteTime; jh<TdvF2$
} ZX~>uf\n
public void run(){ 9~LpO>-
long now = System.currentTimeMillis(); lBizC5t!o
if ((now - lastExecuteTime) > executeSep) { oi33{#%t
//System.out.print("lastExecuteTime:"+lastExecuteTime); uW\@x4
//System.out.print(" now:"+now+"\n"); bIvJs9L
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); R=#q"9qz
lastExecuteTime=now; c,3'wnui
executeUpdate(); Ba"^K d`
} 1NE!=;VOl
else{ _WRR
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); k;"R y8[k
} A{DIp+
} }a #b$]Y
} }mtC6G41Q
//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 IS5.i95m
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类写好了,下面是在JSP中如下调用。 _rWM]
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<% PMz{8
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CountBean cb=new CountBean(); Z=e[
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Zh@4_Z9n!
CountCache.add(cb); *<|~=*Ddf
out.print(CountCache.list.size()+"<br>"); O&rD4#
CountControl c=new CountControl(); :uU]rBMo
c.run(); Tv*1q.MB
out.print(CountCache.list.size()+"<br>"); ?:{0
%>