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: *gM,x4 Y
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CountBean.java DD/>{kff
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/* "'z,[v50&
* CountData.java c%AFo]H
* M1/M}~
* Created on 2007年1月1日, 下午4:44 H{\.g=01
* Ge^zX$.'
* To change this template, choose Tools | Options and locate the template under .pS&0gBo\
* the Source Creation and Management node. Right-click the template and choose M#\ <
* Open. You can then make changes to the template in the Source Editor.
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*/ ;~Q
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package com.tot.count; '%zN
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/** ]6$,IKE7
* ia%z+:G
* @author }}^,7npU
*/ ||-nmOy
public class CountBean { 7|&e[@B
private String countType; :]P~.PD5,
int countId; <Rcu%&;i
/** Creates a new instance of CountData */ YCa@R!M*O
public CountBean() {} :a_BD
public void setCountType(String countTypes){ ~L-0~
this.countType=countTypes; gM4P j[W
} IDy_L;'`*
public void setCountId(int countIds){ T>}0) s
this.countId=countIds; vU=9ydAj?
} LHs-&
public String getCountType(){ ifXW
return countType; Vy-28icZ`
} Tbv/wJ
public int getCountId(){ z;i4N3-:
return countId; :.*HQt9N
} "(s6aqO$
} ')B =|T)
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CountCache.java 1EVfowIl
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/* bS>R5*Zp
* CountCache.java sLb8*fak
* otO
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* Created on 2007年1月1日, 下午5:01 G6ayMw]OF
* et=7}K]l
* To change this template, choose Tools | Options and locate the template under u*2fP]n
* the Source Creation and Management node. Right-click the template and choose 93j{.0]X
* Open. You can then make changes to the template in the Source Editor. R (G2qi
*/ PgMbMH
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package com.tot.count; &VDl/qnaL
import java.util.*; ((XE\V\}Z
/** 8".2)W4*
* Hkdf $$\
* @author _a](V6
*/ )l&D]3$6K
public class CountCache { W{
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public static LinkedList list=new LinkedList(); c!It^*
/** Creates a new instance of CountCache */ B
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public CountCache() {} C5|db{=\.*
public static void add(CountBean cb){ yub{8 f;v
if(cb!=null){ s=Df `
list.add(cb); )0^># k
} ^T:gb]i'Qa
} wd[eJcQ ,
} [ $pmPr2
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CountControl.java Rf)ke("
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/* v?%LQKO
* CountThread.java 44\cI]!{
* MoD?2J
* Created on 2007年1月1日, 下午4:57 UZGDdP
* >O#grDXb
* To change this template, choose Tools | Options and locate the template under w7FoL
* the Source Creation and Management node. Right-click the template and choose i^)WPP>4Aw
* Open. You can then make changes to the template in the Source Editor. hN3u@P^
*/ \ECu5L4
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package com.tot.count; ?P/AC$:|I
import tot.db.DBUtils; =bLY
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import java.sql.*; ~>Kq<]3~
/** +pf5\#l?
* 9XLFHV("
* @author WA6!+Gy
*/ oFDz;6
public class CountControl{ GaekFbW)
private static long lastExecuteTime=0;//上次更新时间 maNW{"1
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 }fZ`IOf
/** Creates a new instance of CountThread */ 0:=ZkEEeU
public CountControl() {} >Kivuc
public synchronized void executeUpdate(){
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Connection conn=null; + H_WlYg-
PreparedStatement ps=null; HfB@vw^
try{ -.IEgggf
conn = DBUtils.getConnection(); )J D(`
conn.setAutoCommit(false); usFfMF X
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); B=Ym x2A9]
for(int i=0;i<CountCache.list.size();i++){ 47r&8C+&\
CountBean cb=(CountBean)CountCache.list.getFirst(); R@iUCT^$
CountCache.list.removeFirst(); J=W0Xi!
ps.setInt(1, cb.getCountId()); l"(6]Z 4
ps.executeUpdate();⑴ l|/LQ/
//ps.addBatch();⑵ @+LfQY
} |Ic`,>XM
//int [] counts = ps.executeBatch();⑶ _oFs #kW
conn.commit(); (`BSVxJH
}catch(Exception e){ r?/A?DMe
e.printStackTrace(); )$Mmn
} finally{ @n&<B`/
try{ O#a6+W"U
if(ps!=null) { o%E;3l
ps.clearParameters(); MJ`3ta
ps.close(); k S#
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ps=null; A{ eL l
} Pmg)v!"
}catch(SQLException e){} Sh6JF574T
DBUtils.closeConnection(conn); zSEs?
} bx4'en#
} }x0- V8
public long getLast(){ :O<bA&:d
return lastExecuteTime; {c?JuV4q?
} y&m0Lz53Z
public void run(){ $~0Q@):
long now = System.currentTimeMillis(); I){\0vb@
if ((now - lastExecuteTime) > executeSep) { F>je4S;
//System.out.print("lastExecuteTime:"+lastExecuteTime); TjMe?p
//System.out.print(" now:"+now+"\n"); LQ11ba
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); l%ayI
lastExecuteTime=now; 2&'|Eqk
executeUpdate(); f3j{V N
} =L|tp%!
else{ 1=sXdcy;
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); #`TgZKDg2
} 1"7Sy3
} i,A#&YDl
} U[L9*=P;
//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 Wz4&7KYY
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类写好了,下面是在JSP中如下调用。 *L6PLe
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<% E!BPE>
CountBean cb=new CountBean(); -9
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); d)cOhZy
CountCache.add(cb); Z/x*Y#0@n
out.print(CountCache.list.size()+"<br>"); 8.'#?]a
CountControl c=new CountControl(); b*a2,MiM
c.run(); BqDKT
out.print(CountCache.list.size()+"<br>"); iv`O/T
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