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: /^i7^
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CountBean.java nxKV7d@R
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/* ]P<u^ `{*
* CountData.java ^hq`dr|R=
* u8v;O}#
* Created on 2007年1月1日, 下午4:44 a"0Xam
* 1xar
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* To change this template, choose Tools | Options and locate the template under e54wAypPOl
* the Source Creation and Management node. Right-click the template and choose BYyR-m
* Open. You can then make changes to the template in the Source Editor. p./zW
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*/ s6lo11
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package com.tot.count; *@S:f"i
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/** GP<A v1
* 9sFZs]uM
* @author G}&B{Ir
*/ /z>G=kA
public class CountBean { ZC@ 33Q(
private String countType; (2[tQ`~
int countId; [DC8X P5<
/** Creates a new instance of CountData */ ?V4?r2$c
public CountBean() {} (q59cA w~X
public void setCountType(String countTypes){ f6j;Y<}' g
this.countType=countTypes; >_jT.d
} ?"N,do
public void setCountId(int countIds){ btJ:Wt}
this.countId=countIds; Waj6.PCFm
} X&8&NkH
public String getCountType(){ oa? bOm
return countType; G<# 9`
} }Ry:})
public int getCountId(){ S4aN7.'Q
return countId; 7;jwKA;k
} Kp'_lKW)]q
} 2%'{f
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CountCache.java -hiG8%l5
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/* O; 7`*}m
* CountCache.java ?{NP3
* zt/b S/
* Created on 2007年1月1日, 下午5:01 ?'Y\5n/*$
* (/Lo44wT
* To change this template, choose Tools | Options and locate the template under 6oMU) DIa
* the Source Creation and Management node. Right-click the template and choose SMY,bU'a
* Open. You can then make changes to the template in the Source Editor. e;GLPB
*/ 26.),a
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package com.tot.count; NGcd
import java.util.*; SU~t7Ta!G
/** P$ZIKkf
* l=ehoyER
* @author ~[l6;bn
*/ fb3(9
public class CountCache { 6c,]N@,Zw
public static LinkedList list=new LinkedList(); 0+L:+S
/** Creates a new instance of CountCache */
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public CountCache() {} {4J:t_<nKO
public static void add(CountBean cb){ Anr''J&9`H
if(cb!=null){ 1O]'iS"
list.add(cb); epuN~T
} >?aPXC
} {AUhF}O
} mSF>~D1_
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CountControl.java 0tyoH3o/d
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/* Hof@,w
* CountThread.java meey5}
* r6S-G{o
* Created on 2007年1月1日, 下午4:57 "HX,RJ
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* y (@j;Q3(r
* To change this template, choose Tools | Options and locate the template under 7DZxrVw
* the Source Creation and Management node. Right-click the template and choose .<7M4Z
* Open. You can then make changes to the template in the Source Editor. @SeInew;`l
*/ tIn
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package com.tot.count; $c"byQ[3S
import tot.db.DBUtils; 9'nM$a
import java.sql.*; wX5Yo{
/** 2[!#Xf
* Bn:"qN~
* @author J<hqF4z
*/ :/UO3 c(
public class CountControl{ OH.^m6Z
private static long lastExecuteTime=0;//上次更新时间 9Rl-Jz8g
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 WzG]9$v &
/** Creates a new instance of CountThread */ _3@[S
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public CountControl() {} yvR3|
public synchronized void executeUpdate(){ `#@#eZ
Connection conn=null; eajctkzj
PreparedStatement ps=null; r9MS,KG8
try{ do,ZCn
conn = DBUtils.getConnection(); H4RqOI
conn.setAutoCommit(false); qLC_p)
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); &!i'Q;q
for(int i=0;i<CountCache.list.size();i++){ ! |4fww
CountBean cb=(CountBean)CountCache.list.getFirst(); cxX/ b,
CountCache.list.removeFirst(); F{*{f =E!B
ps.setInt(1, cb.getCountId()); U}f"a!
ps.executeUpdate();⑴ DBTeV-G9~R
//ps.addBatch();⑵ OM,Dy&Y
} ^97u0K3$
//int [] counts = ps.executeBatch();⑶ [0c7fH`8V
conn.commit(); wHx@&Tp
}catch(Exception e){ 5rp,xk!
e.printStackTrace(); /B"FGa04p(
} finally{ g
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try{ (sM$=M<$
if(ps!=null) { WxPu{N
ps.clearParameters(); *^[m?3"W
ps.close(); @yV.Yx"p_
ps=null; gn82_
} <&w(%<;
}catch(SQLException e){} zXX=WH
DBUtils.closeConnection(conn); kXW5bR
} #/N;ScyUJT
} t =LIkwD
public long getLast(){ !m]_tB
return lastExecuteTime; 7sypU1V6
} -Cn x!g}
public void run(){ up _Qv#`Q
long now = System.currentTimeMillis(); +"} #4
if ((now - lastExecuteTime) > executeSep) { B`{7-Asc1
//System.out.print("lastExecuteTime:"+lastExecuteTime); ?,XrZRF
//System.out.print(" now:"+now+"\n"); D[jPz0
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); \B/!}Tn;
lastExecuteTime=now; zX]4DLl,
executeUpdate(); 9}-;OJe
} ( JMk0H3u
else{ Gx)U~L$B
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); $Gs9"~z?;
} @kstG3@
} r+%$0eB1^
} eewlK]
//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 'kuLkM,
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类写好了,下面是在JSP中如下调用。 FTgqE@
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<% H8!;
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CountBean cb=new CountBean(); 8kdJ;%^N
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 2^aXXPC
CountCache.add(cb); 4 H9mKR
out.print(CountCache.list.size()+"<br>"); i<\WRzVT
CountControl c=new CountControl(); #'y4UN
c.run(); DpbprT7_
out.print(CountCache.list.size()+"<br>"); aHR+4m~)
%>