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: >FhBl\oIi
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CountBean.java k9?+9bExXA
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/* arrcHf4O
* CountData.java E':Z_ ^4
* p.olXP
* Created on 2007年1月1日, 下午4:44 v#G ^W
* s os&
* To change this template, choose Tools | Options and locate the template under r}bKVne
* the Source Creation and Management node. Right-click the template and choose hR{Zh>
* Open. You can then make changes to the template in the Source Editor. ;I'["k%
*/ rKq]zHgpo
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package com.tot.count; ["9$HL
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/** Z2
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* d_hcv|%
* @author ~VKXL,.
*/ Pl>t\`1:|A
public class CountBean { R~([
private String countType; tDVdl^#
int countId; :gC2zv
/** Creates a new instance of CountData */ [5-5tipvWp
public CountBean() {} *WG}K?"/
public void setCountType(String countTypes){ Qa+gtGtJ
this.countType=countTypes; /0(KKZ)
} /|f]L9)2<
public void setCountId(int countIds){ v2Y=vr
this.countId=countIds; B*7o\~5
} Yn/-m
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public String getCountType(){
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return countType; n66_#X
} DQ$/0bq
public int getCountId(){ 2)YLs5>W%
return countId; O&uOm:/(
} W#Z]mt B
} TrW3@@}j
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CountCache.java QNY{pk
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/* &XP 0
* CountCache.java &[uGfm+@
* TEtZPGFl
* Created on 2007年1月1日, 下午5:01 (ydeZx
* ;Xns 9
* To change this template, choose Tools | Options and locate the template under J4<*KL~a
* the Source Creation and Management node. Right-click the template and choose ]Az >W*Y
* Open. You can then make changes to the template in the Source Editor. `4MPXfoBL
*/ Y9N:%[ :>W
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package com.tot.count; *zcH3a,9"x
import java.util.*; 42M3c&@P
/** apXq$wWq{D
* pH%K4bV)8
* @author Qa=;Elp:[
*/ e j~ /sO
public class CountCache { ?`xId;}J#7
public static LinkedList list=new LinkedList(); {sLh=iK
/** Creates a new instance of CountCache */ Y`wi=(
public CountCache() {} 4{V=X3,x
public static void add(CountBean cb){ qlu yJpt
if(cb!=null){ c72/e7gV
list.add(cb); " 1Bn/Q
} s$Mj4_p3l
} YeQX13C"Z
} H:`r!5&Qb5
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CountControl.java [ 6M8a8C
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/* :\ S3[(FV
* CountThread.java `k+k&t
* ^>>Naid
* Created on 2007年1月1日, 下午4:57 ev>: 3_ s
* =8]'/b
* To change this template, choose Tools | Options and locate the template under j$,`EBf`:<
* the Source Creation and Management node. Right-click the template and choose g#e"BBm=A
* Open. You can then make changes to the template in the Source Editor. Kxg09\5i
*/ z;-2xD0&U[
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package com.tot.count; ~o+u: ]
import tot.db.DBUtils; )gE:@3
import java.sql.*; q
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/** -C\m'T,1
* !!9V0[
* @author qYE -z(i
*/ h'
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public class CountControl{ >q`G?9d2
private static long lastExecuteTime=0;//上次更新时间 ZEB1()GB
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 rHMsA|xz6
/** Creates a new instance of CountThread */ {pVD`#Tl[
public CountControl() {} TOQvZ?_
public synchronized void executeUpdate(){ r8mE
Connection conn=null; sGV%O=9?2
PreparedStatement ps=null; "UE'dWz
try{ 2D
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conn = DBUtils.getConnection(); _:{XL c
conn.setAutoCommit(false); Ls9G:>'rR
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 2rA`y8g(L
for(int i=0;i<CountCache.list.size();i++){ &AW?!rH
CountBean cb=(CountBean)CountCache.list.getFirst(); ?R";EnD
CountCache.list.removeFirst(); I`
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ps.setInt(1, cb.getCountId()); wsM5TB
ps.executeUpdate();⑴ xX}vxhN
//ps.addBatch();⑵ 8Y:bvs.j
} -E.EI@"
//int [] counts = ps.executeBatch();⑶ TK'(\[E
conn.commit(); J6jrtLh
}catch(Exception e){ TN&1C8xr
e.printStackTrace(); /QTGZb
} finally{ .Emw;+>
try{ Hq=RtW2
if(ps!=null) { QQqWJq~
ps.clearParameters(); i2EB.Zlv
ps.close(); Nhs]U`s(g
ps=null; 9^`G `D
} * ,,D%L
}catch(SQLException e){} HZR~r:_
i
DBUtils.closeConnection(conn); e KET8v[
} w+PbT6;
} *2@Ne[dYEF
public long getLast(){ I( pU_7mw
return lastExecuteTime; lepgmQ|oY
} &AC-?R|Dp
public void run(){ A2]N :=
long now = System.currentTimeMillis(); oMcX{v^"
if ((now - lastExecuteTime) > executeSep) { 6Vi #O^>
//System.out.print("lastExecuteTime:"+lastExecuteTime); Ip|7JL0Z
//System.out.print(" now:"+now+"\n"); j&ddpS(s
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); K" Y,K
lastExecuteTime=now; M++*AZ
executeUpdate(); 0/;T\9
} LDO@$jg
else{ ^KmyB6Yg
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ]e 81O#t3
} ACc.&,!IZ
} cvi+AZ=
} B$aboL2
//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 5{VrzzOK}
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类写好了,下面是在JSP中如下调用。 -_v[oqf$
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<% buq3t+0
CountBean cb=new CountBean(); 's+ Fd~'
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); H;%a1
CountCache.add(cb); gtJUQu p2
out.print(CountCache.list.size()+"<br>"); i e%ZX
CountControl c=new CountControl(); mbU[fHyV
c.run(); _"Y;E
out.print(CountCache.list.size()+"<br>"); ZI-)'
%>