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: 2HemPth
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CountBean.java "5,tEP!
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/* :DlgNR`bq
* CountData.java t<|S7EqIL
* &(]@L\A
* Created on 2007年1月1日, 下午4:44 1dy>a=W
* z!r-g(^G
* To change this template, choose Tools | Options and locate the template under 7z=zJ4C
* the Source Creation and Management node. Right-click the template and choose 3.
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* Open. You can then make changes to the template in the Source Editor. gfPht 5
*/ -!k$ Z
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package com.tot.count; DKG%z~R*
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/** ;QA`2$Ow
* .%pbKi
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* @author $YX\&%N
*/ 'F- wC!
public class CountBean { lbCTc,xT
private String countType; Vg0$5@
int countId; zIyMq3
/** Creates a new instance of CountData */ >J]^Rgn>
public CountBean() {} ^ MUSq(
public void setCountType(String countTypes){ _'yN4>=6u
this.countType=countTypes; RiY9[ec2
} 2$g3ABfV
public void setCountId(int countIds){ i8\&J.
this.countId=countIds; 8$H_:*A?
} d3$&I==;:
public String getCountType(){
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return countType; ptrQ~m-
} 5jTBPct
public int getCountId(){ K9#=@}!3L
return countId; ]+SVQ|v0
} /=5YHq>
} I'_u4
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CountCache.java UUf-G0/P
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/* kXmnLxhS/
* CountCache.java hf/6VlZ
* t_-1sWeA!
* Created on 2007年1月1日, 下午5:01 [q/tKdo@
* \Qh{uk[
* To change this template, choose Tools | Options and locate the template under x>?jfN,e
* the Source Creation and Management node. Right-click the template and choose >>**n9\q
* Open. You can then make changes to the template in the Source Editor. f#s
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*/ fI5]ed eS
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package com.tot.count; "QWF&-kAI
import java.util.*; x2|YrkGv
/** :3z`+5Y*
* ~JJuM
* @author GvL)SVv?
*/ E,F'k2yU
public class CountCache { 1 h.=c
public static LinkedList list=new LinkedList(); )}-,4Iu%
/** Creates a new instance of CountCache */ &B</^:
public CountCache() {} S}/?Lm}
public static void add(CountBean cb){ ?Mb'l4
if(cb!=null){ 8b0!eB#_Ee
list.add(cb); L"w% ew
} L8&$o2+07r
} '.sS"QdN
} y|BRAk&n
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CountControl.java "Dc6kn^}3
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/* d+1q[,-
* CountThread.java 9aED6
* :|s!_G <
* Created on 2007年1月1日, 下午4:57 G8w<^z>pTg
* O>Vb7`z0<
* To change this template, choose Tools | Options and locate the template under \"]vSx>
* the Source Creation and Management node. Right-click the template and choose S1iF1X(+?X
* Open. You can then make changes to the template in the Source Editor. pZS0;T]W,
*/ ZeUA e
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package com.tot.count; ewNzRH,b
import tot.db.DBUtils; ]wH,534
import java.sql.*; `CWI%V
/** y<Hka'(%
* @WV}VKm
* @author vtvF)jlX
*/ "ooq1
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public class CountControl{ r[
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private static long lastExecuteTime=0;//上次更新时间 .Ulrv5wJ
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 1@&i
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/** Creates a new instance of CountThread */ ?onaJ=mT
public CountControl() {} 8X6F6RK6,1
public synchronized void executeUpdate(){ CCCd=s.
Connection conn=null; W6_~.m"b
PreparedStatement ps=null; Xknp*(9
try{ <5R`E(
conn = DBUtils.getConnection(); rOt`5_2f
conn.setAutoCommit(false); C%$:Oq
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 7oPLO(0L
for(int i=0;i<CountCache.list.size();i++){ Y#>'.$(Az
CountBean cb=(CountBean)CountCache.list.getFirst(); C@{#OOa
CountCache.list.removeFirst(); |i)7jG<
ps.setInt(1, cb.getCountId()); Lci SQ
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ps.executeUpdate();⑴ 3ErW3Ac Ou
//ps.addBatch();⑵ I<v1S
} mE`OG8
//int [] counts = ps.executeBatch();⑶ ?#OGH`ZvkI
conn.commit(); pvCf4pf~
}catch(Exception e){ 9~bl
e.printStackTrace(); }:5_vH0
} finally{ Pc+8CuN?
try{ mVJW"*}8
if(ps!=null) { DAZzc :1Aj
ps.clearParameters(); g_kR5Wxpt
ps.close(); <Yzk]98W5.
ps=null; ,G";ny[$
} \7W4)>At-
}catch(SQLException e){} ~]}V"O%,
DBUtils.closeConnection(conn); HgHhc&-
} V-#OiMWa~
} >k:BG{$Kae
public long getLast(){ IO,ddVO
return lastExecuteTime; v!\\aG/
} <M(Jqb cWa
public void run(){ { o2pCH
long now = System.currentTimeMillis(); AOT +4*)%
if ((now - lastExecuteTime) > executeSep) { p$>e{-u
//System.out.print("lastExecuteTime:"+lastExecuteTime); _/@VV5Mq
//System.out.print(" now:"+now+"\n"); F\' ^DtB
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); N!7r~B
lastExecuteTime=now; .AEOf0t
executeUpdate(); ZG=B'4W
} 'S_kD! BO
else{ wz!a;]agg
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ^tWt"GgC
} -8sm^A>C
} K+3dwQo
} >C6wm^bl
//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 0FA
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类写好了,下面是在JSP中如下调用。 (&n4^tJ+_
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<% L0v& m
CountBean cb=new CountBean(); \,:3bY_d
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ^%)H;
CountCache.add(cb); r?{$k3Vl
out.print(CountCache.list.size()+"<br>"); 3Uzb]D~u
CountControl c=new CountControl(); 4)'8fi
c.run(); 2_^{Vez@I
out.print(CountCache.list.size()+"<br>"); SfKm]Z>Hp
%>