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: !p"Kd ~
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CountBean.java :SdIU36
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/* vcV!K^M-
* CountData.java wRj~Qv~E
* /O_0=MLp
* Created on 2007年1月1日, 下午4:44 F*.
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* rr>IKyI'
* To change this template, choose Tools | Options and locate the template under CP@o,v-
* the Source Creation and Management node. Right-click the template and choose v$Dh.y
* Open. You can then make changes to the template in the Source Editor. I,w^?o
*/ ko>M&/^
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package com.tot.count; ,A^L=+
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/** <BQ%8}
* L#[HnsLp_
* @author . ^BWR
*/ 83B\+]{hD
public class CountBean { $=7H1 w
private String countType; 2"zI R(
int countId; }@3$)L%n_u
/** Creates a new instance of CountData */ ?DJuQFv
public CountBean() {} e1oFnu2R
public void setCountType(String countTypes){ ^NcTWbs-T
this.countType=countTypes; @f-0X1C."N
} rnJS[o0
public void setCountId(int countIds){ 1o(+rR<h9
this.countId=countIds; qmQFHC_
} 9'D8[p%
public String getCountType(){ w"yK\OE
return countType; W5TqC
} H+nr5!`kz
public int getCountId(){ UnJi& ~O
return countId; 1LV|t+Sex
} ><MGZ?-N
} Lqg7D\7j
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CountCache.java [''=><
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/* }ZxW"5oq
* CountCache.java RJQ/y3
* 3L%Y"4(mm
* Created on 2007年1月1日, 下午5:01 "X\q%%P=?
* u!sSgx=
* To change this template, choose Tools | Options and locate the template under ^Z#<tN;
* the Source Creation and Management node. Right-click the template and choose \xy:6gd:
* Open. You can then make changes to the template in the Source Editor. }Ox2olUX
*/ Rh5@[cg%
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package com.tot.count; ;""-[4C
import java.util.*; u0<d2Y
/** wI|bBfd(
* y}s
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* @author **"zDY*?W
*/ (\5<GCW-
public class CountCache { \z(>h&
public static LinkedList list=new LinkedList(); I$rW[l2
/** Creates a new instance of CountCache */ QSlf=VK*y
public CountCache() {} n:%'{}Jw
public static void add(CountBean cb){ _Eet2;9
if(cb!=null){ %a%+!wX0x
list.add(cb); -Hl\j(D7
} LWp?U!N
} 7!]k#|u
} 'eTpcrS3
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CountControl.java 67EDkknt
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/* ]}*G[[
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* CountThread.java = m!!
* t/4/G']W
* Created on 2007年1月1日, 下午4:57 mo97GW
* *
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* To change this template, choose Tools | Options and locate the template under ^+.e5roBKj
* the Source Creation and Management node. Right-click the template and choose JJ= ~o@|c
* Open. You can then make changes to the template in the Source Editor. ^$^Vd@t>a
*/ vCrWA-q#
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package com.tot.count; l-JKcsM
import tot.db.DBUtils; pD)/-Dgdm
import java.sql.*; [9# #Kb
/** B@:XC&R^
* *8(t y%5F0
* @author v:!7n
*/ FL*w(Br.
public class CountControl{ 6 I>xd
private static long lastExecuteTime=0;//上次更新时间 $(!D/bvJ
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 3vEjf
/** Creates a new instance of CountThread */ !3gpiQH{
public CountControl() {} |R|U z`
public synchronized void executeUpdate(){ Ix l"'Q_z
Connection conn=null; E,nYtn|B
PreparedStatement ps=null; HEW9YC"
try{ :+X2>Lu$FA
conn = DBUtils.getConnection(); 7xa@wa?!L
conn.setAutoCommit(false); )r-|T&Sn
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 4h0jX9
for(int i=0;i<CountCache.list.size();i++){ Hr64M0V3B
CountBean cb=(CountBean)CountCache.list.getFirst(); "!4>gg3r
CountCache.list.removeFirst(); ^5iY/t~Q
ps.setInt(1, cb.getCountId()); q=L*
99S
ps.executeUpdate();⑴ LKwUpu!
//ps.addBatch();⑵ mU0r"\**c3
} ;Bc<u[G
//int [] counts = ps.executeBatch();⑶ Yk*57&QI
conn.commit(); [n@!=T
}catch(Exception e){ TW;;OS[
e.printStackTrace(); *p<5(-J3
} finally{ UEdl"FwM4
try{ 'V*M_o(\
if(ps!=null) { gpTF^.(
ps.clearParameters(); PX>\j&
ps.close(); ():?FJM
ps=null; 8f`b=r(a>
} .TrQ +k>
}catch(SQLException e){} ]> "/<"
DBUtils.closeConnection(conn); )*AA9
} q@!H^hd}
} oVZ8p-
public long getLast(){ i)^ZH#Gp
return lastExecuteTime; ?@ye*%w_
} *,=+R$
public void run(){ 3'NL1d u
long now = System.currentTimeMillis(); &+|4(d1
if ((now - lastExecuteTime) > executeSep) { b.u8w2(
//System.out.print("lastExecuteTime:"+lastExecuteTime); g|*eN{g]uE
//System.out.print(" now:"+now+"\n"); 'f<_SKd
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ;.[$
lastExecuteTime=now; Ej3hdi)
executeUpdate(); 'C8=d(mR=m
} }u*@b10
else{ ^+l\YB7pD
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); VX@G}3Ck
} |ssIUJ
} 9%k.GE
} = 8e8!8
//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 :[rKSA]@
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类写好了,下面是在JSP中如下调用。 Xr6 !b:UX
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<% N5_.m(:
CountBean cb=new CountBean(); 8 =Lv7G%
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ~O7(0RsCN
CountCache.add(cb); %YAiSSsV
out.print(CountCache.list.size()+"<br>"); HPH {{p
CountControl c=new CountControl(); %>U*A
c.run(); A0k>Nb\c3
out.print(CountCache.list.size()+"<br>"); :pu{3-n.
%>