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: .#[ 9q-
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CountBean.java _CwTe=K}
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/* 4~fYG| a
* CountData.java NL21se
* n`Q@<op
* Created on 2007年1月1日, 下午4:44 K;F1'5+=D
* 01cBAu
* To change this template, choose Tools | Options and locate the template under Q\Ek U.[I
* the Source Creation and Management node. Right-click the template and choose /%@;t@BK4
* Open. You can then make changes to the template in the Source Editor. >eJ<-3L;
*/ 1J?v\S$ma`
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package com.tot.count; .9~j%]q
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/** vDjH $ U
* 2 bc&sU)X
* @author hU?DLl:bXF
*/ MAh1tYs4D
public class CountBean { I)rnF
private String countType; qng ~,m
int countId; a5*r1,
/** Creates a new instance of CountData */ ImXYI7PL
public CountBean() {} \&"C
public void setCountType(String countTypes){ 1%Xh[
this.countType=countTypes; w h$bDTCj
} U>S
public void setCountId(int countIds){ 4XkI? l
this.countId=countIds; 7|,L{~
} (r|m&/
public String getCountType(){ sJ6.3=
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return countType; <PLAAh8
} )+.=z
public int getCountId(){ 5`h$^l/
return countId; kx,.)qKk
} qC`}vr|Z
} C- .;m
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CountCache.java br I;}m
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/* Z?)g'n
* CountCache.java BJ|l
* "O34 E?ql.
* Created on 2007年1月1日, 下午5:01 6bm 7^e(
* ,#Z%0NLe
* To change this template, choose Tools | Options and locate the template under [LoQYDku
* the Source Creation and Management node. Right-click the template and choose HP# SR';E
* Open. You can then make changes to the template in the Source Editor. g~hMOI?KK^
*/ KC;cu%H
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package com.tot.count; !"^Zr]Qt+\
import java.util.*; b\P:a_vq
/** }g bLWx'iG
* 5B=uvp|Y
* @author yE}\4_0I/
*/ }c/p;<
public class CountCache { bP18w0>,
public static LinkedList list=new LinkedList(); $1yy;IyR
/** Creates a new instance of CountCache */ eiMP:
public CountCache() {} h;V4|jM
public static void add(CountBean cb){ BH:A]#_{
if(cb!=null){ ocGrB)7eD
list.add(cb); ^/C\:hw
} :>FN|fz
} JduO^Fit
} gUklP(T=u
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CountControl.java ciS +.%7
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/* o/Ismg-p
* CountThread.java /.]u%;%r[
* v>8.TE~2
* Created on 2007年1月1日, 下午4:57 %o?)`z9-
* ;,77|]<XE
* To change this template, choose Tools | Options and locate the template under HE&)N
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* the Source Creation and Management node. Right-click the template and choose KA2>[x2
* Open. You can then make changes to the template in the Source Editor. XvI~"}
*/ $1.-m{Bd
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package com.tot.count; }#ink4dK:
import tot.db.DBUtils; WARiw[
import java.sql.*; |[`YGA4
/** m)A:w.o
* )LGVR3#
* @author \5a.JfF
*/ {o~TbnC
public class CountControl{ ad}8~6}_&
private static long lastExecuteTime=0;//上次更新时间 A4zI1QF
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 [FBS|v#T
/** Creates a new instance of CountThread */ wO]e%BTO
public CountControl() {} y8YsS4E^Q
public synchronized void executeUpdate(){ d88A.Z3w
Connection conn=null; ]Thke 4
PreparedStatement ps=null; 5aaM;45C
try{ vn}m-U XA*
conn = DBUtils.getConnection(); 2E1`r@L
conn.setAutoCommit(false); 0OO[@Ht
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Y%;J/4dd
for(int i=0;i<CountCache.list.size();i++){ .57p4{
CountBean cb=(CountBean)CountCache.list.getFirst(); -))S
CountCache.list.removeFirst(); NgTB4I8P
ps.setInt(1, cb.getCountId()); -Cyo2wk
ps.executeUpdate();⑴ 35l%iaj]G5
//ps.addBatch();⑵ N**)8(
} ].Yz
=:
//int [] counts = ps.executeBatch();⑶ !7DDPJ~
conn.commit(); UOb`@#
}catch(Exception e){ NVRzthg%c_
e.printStackTrace(); 0si1:+t-[+
} finally{ X,G<D}
try{ [W3X$r~-
if(ps!=null) { lk>\6o:
ps.clearParameters(); QF/ULW0G!
ps.close(); h^g0|p5
ps=null; R=~%kt_n
} UN'n~d@~
}catch(SQLException e){} 8?iI;(
DBUtils.closeConnection(conn); ~vz%I^xW
} ;qaPK2a8
} WkXgz6 P
public long getLast(){ Ah1
9#0
return lastExecuteTime; SVo ?o|<
} *k7BE_&*0Z
public void run(){ Qa,=
long now = System.currentTimeMillis(); Nf([JP% 4
if ((now - lastExecuteTime) > executeSep) { 'S3<' X
//System.out.print("lastExecuteTime:"+lastExecuteTime); +%YBa'Lk
//System.out.print(" now:"+now+"\n"); b*Y Wd3
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); .=;IdLO,Bf
lastExecuteTime=now; dGp7EB`
executeUpdate(); "r46Rfa
} wPM&N@Pf
else{ O2 >c|=#
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); WGz)-IB!PE
} ]qqgEZ1!Y
} hnFpC1TO
} >[Vc$[62
//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 FGi7KV=N
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类写好了,下面是在JSP中如下调用。 *,JE[M
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<% bVzi^R"
CountBean cb=new CountBean(); 0o+Yjg>\~8
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); e4` L8
CountCache.add(cb); #VrIU8Q7'
out.print(CountCache.list.size()+"<br>"); ;(?tlFc
CountControl c=new CountControl(); o{y}c->
c.run(); ol"|?*3q
out.print(CountCache.list.size()+"<br>"); d 5yEgc;z
%>