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: @~N#)L^
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CountBean.java *@BBlkcx
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/* O-'T*M>
* CountData.java 1^W Aps
* A6U6SvM;
* Created on 2007年1月1日, 下午4:44 DHJnz>bE
* %vThbP#mR|
* To change this template, choose Tools | Options and locate the template under rU~"A
* the Source Creation and Management node. Right-click the template and choose B " B
* Open. You can then make changes to the template in the Source Editor. >C&!#
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*/ eb8_guZ
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package com.tot.count; }}xR?+4A
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/** 02+^rqIx5
* T(}da**X
* @author y\)w#
*/ ;kF p)*i
public class CountBean { ;s!H
private String countType; W UV Q_<i+
int countId; gI%n(eY
/** Creates a new instance of CountData */ 'qD9kJ`
public CountBean() {} >L(F{c:
public void setCountType(String countTypes){ qqAsh]Z
this.countType=countTypes; jGWLYI=V2
} JjCf<ktE.
public void setCountId(int countIds){ | UaI i^
this.countId=countIds; Af%?WZlOq
} ?=G H{
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public String getCountType(){ m6gr!aT
return countType; oe<Y,%u"6
} iUKj:q:
public int getCountId(){ \r2qH0B
return countId; O*PHo_&G
} 'GyPl
} g:)vthOs
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CountCache.java f:SF&t*
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/* ;0*^9 8K
* CountCache.java y{sA[ "
* WWLVy(
* Created on 2007年1月1日, 下午5:01 Rt|Hma
* qw/{o:ce]
* To change this template, choose Tools | Options and locate the template under aFym&n\
* the Source Creation and Management node. Right-click the template and choose xRUYJ=|oh
* Open. You can then make changes to the template in the Source Editor. 6.jZy~
*/ yM2&cMHH~
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package com.tot.count; !O-+h0Z
import java.util.*; iQF}x&a<
/** t;]egk
* -(.7/G'Vk>
* @author ss<'g@R
*/ B`aAvD`7
public class CountCache { |DD?3#G01
public static LinkedList list=new LinkedList(); %np#Bv-L
/** Creates a new instance of CountCache */ Uz|]}t5V
public CountCache() {} yh:,[<q
public static void add(CountBean cb){ aAM UJk
if(cb!=null){ d@tr]v5 B
list.add(cb); H~i],WD
} G,-OH-M!
} +a-@
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} t]
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CountControl.java HqBPY[;s
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/* ;l ()3;
* CountThread.java ai4^NJn
* fJ2{w[ne
* Created on 2007年1月1日, 下午4:57 L@r.R_*H?s
* ?8@*q6~8
* To change this template, choose Tools | Options and locate the template under kVnyX@
* the Source Creation and Management node. Right-click the template and choose QtQ^"d65
* Open. You can then make changes to the template in the Source Editor. --`LP[ll
*/ Rk%M~ D*-
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package com.tot.count; %k
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import tot.db.DBUtils; Qu FCc1Q
import java.sql.*; K)&XQ`&
/** -/c1qLdQ
* FM"BTA:C
* @author 7 afA'.=
*/ ' u};z:t
public class CountControl{ ;}~Bv<#
private static long lastExecuteTime=0;//上次更新时间 L"7`
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 [KI`e
/** Creates a new instance of CountThread */ !a(qqZ|s
public CountControl() {} jjT2k
public synchronized void executeUpdate(){ ysJhP .
Connection conn=null; )^S^s>3
PreparedStatement ps=null; :YXQ9/iRr
try{ 1vK(^u[
conn = DBUtils.getConnection(); ":#x\;
conn.setAutoCommit(false); {_ho!OS>
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); I+?$4SC
for(int i=0;i<CountCache.list.size();i++){ _AHB|P I
CountBean cb=(CountBean)CountCache.list.getFirst(); 8tRhV2
CountCache.list.removeFirst(); ae#HA[\0G
ps.setInt(1, cb.getCountId()); n[:AV
ps.executeUpdate();⑴ 7K]U|K#
//ps.addBatch();⑵ b;`#Sea
} 2]RH)W86;
//int [] counts = ps.executeBatch();⑶ +6)kX4
conn.commit(); C+]q
}catch(Exception e){ `{Di*
e.printStackTrace(); qMdtJ(gq
} finally{ X1V}%@3:
try{ VmH_0IM^6
if(ps!=null) { p C2c(4
ps.clearParameters(); 6dR-HhF
ps.close(); 9Glfi@.
ps=null; O{cGk:
y
} g yH7((#i
}catch(SQLException e){} ?)o4 Kt'h
DBUtils.closeConnection(conn); >;&V~q:di
} ])ALAAIc-
} %)hIpxOrX
public long getLast(){ L!b0y7yR
return lastExecuteTime; uZ`d&CEh
} ywQ!9 \
public void run(){ B/9<b{6
long now = System.currentTimeMillis(); >5~Zr$
if ((now - lastExecuteTime) > executeSep) { {Fp`l\,
//System.out.print("lastExecuteTime:"+lastExecuteTime); b^l
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//System.out.print(" now:"+now+"\n"); 6=g]Y!o$
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); .";tnC!e
lastExecuteTime=now; B[/['sD
executeUpdate(); >gZk
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} ND55`KT4
else{ vPl6Dasr
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); *CPB5s
} wp]7Lx?F
} .1z$ A
} lgjoF_D
//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 8T.5Mhx0jS
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类写好了,下面是在JSP中如下调用。 AR+\uD=\I-
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<% mb~=Xyk&
CountBean cb=new CountBean(); :U-US|)(2
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); S `m-5
CountCache.add(cb); QC\g%MVG
out.print(CountCache.list.size()+"<br>"); wUIsi<Oj
CountControl c=new CountControl(); 1y)$[e
c.run(); #EQx
out.print(CountCache.list.size()+"<br>"); ;( Ajf.i
%>