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: *^y,Gg/
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CountBean.java &u`EYxT
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/* ygK@\JHn
* CountData.java Mmmg3%G1
* Bnp\G h
* Created on 2007年1月1日, 下午4:44 1.0:
* !;3hN$5
* To change this template, choose Tools | Options and locate the template under <-6f}wN
* the Source Creation and Management node. Right-click the template and choose KvjsibI/Y
* Open. You can then make changes to the template in the Source Editor. CCHGd&\Z
*/ &]"Z x0t5%
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package com.tot.count; }j$tFFVi~
*I:a\o~$[
/** _-|/$ jZ
* .oS[ DTn5S
* @author DD5cUlOSu
*/ q2b>Z6!5
public class CountBean { M!YGv
private String countType; Pm7lP5
int countId; T mK[^
/** Creates a new instance of CountData */ S5BS![-QK
public CountBean() {} P3!JA)p6a
public void setCountType(String countTypes){ }}qY,@eeX
this.countType=countTypes; ' hDs.Wnu
} -zg 6^f_pW
public void setCountId(int countIds){ HvR5-?qQ
this.countId=countIds; ^
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} $D='NzE/
public String getCountType(){ x)jc
return countType; C2CR#b=)i
} :d6]rOpX
public int getCountId(){ D GL=\
return countId; $."DOZQ3U
} 2KlVj]!7
} An_3DrUFV_
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CountCache.java \JC_"gqt
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/* EQe$~}[
* CountCache.java ZkWMo=vL
* -_xTs(;|8
* Created on 2007年1月1日, 下午5:01 6?ky~CV
* 9?q ^yy
* To change this template, choose Tools | Options and locate the template under o5['5?i} /
* the Source Creation and Management node. Right-click the template and choose ~g9~D}48k'
* Open. You can then make changes to the template in the Source Editor. (}5};v
*/ ^M1jv(
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package com.tot.count; <Mndr8 H
import java.util.*; u+y3(0
/** ![!,i\x
* ]XcWGQv~
* @author ]4/C19Fe!
*/ ._]*Y`5)d
public class CountCache { g*Pn_Yo[.
public static LinkedList list=new LinkedList(); /U,(u9bq
/** Creates a new instance of CountCache */ '[HBKn$`
public CountCache() {} iMv):1p>8
public static void add(CountBean cb){ aeVd.`lxM
if(cb!=null){ qC=9m[MI
list.add(cb); 1h|qxYO
} H2xDC_Fs
} m7`S@qG
} ecx_&J@D
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CountControl.java ~$ Po3]{s
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/* tS Y4'
* CountThread.java KYy oN
* ~c55LlO>
* Created on 2007年1月1日, 下午4:57 lKf kRyO_S
* W6`_lGTj
* To change this template, choose Tools | Options and locate the template under nTw:BU4jd
* the Source Creation and Management node. Right-click the template and choose mML B?I
* Open. You can then make changes to the template in the Source Editor. MR: H3
*/ [VLq/lg*
^$mCF%e8H
package com.tot.count; I?nU+t;
import tot.db.DBUtils; Zl>wWJ3y
import java.sql.*; Unansk
/** |9F-ZH~6
* <(~Wg{
* @author >l=jJTJ;q
*/ Uu@qS
public class CountControl{ unRFcjEa
private static long lastExecuteTime=0;//上次更新时间 v9!]/]U^
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 FjI1'Ah\
/** Creates a new instance of CountThread */ dQFUQ
public CountControl() {} \rT>&o .i
public synchronized void executeUpdate(){ tR4+]K
Connection conn=null; i+Mg[x$.
PreparedStatement ps=null; U6o]7j&6
try{ /XA*:8~!
conn = DBUtils.getConnection(); &_s^C?x
conn.setAutoCommit(false); ,,1y0s0`
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 6ZwQ/~7H
for(int i=0;i<CountCache.list.size();i++){ dtjb(*x
CountBean cb=(CountBean)CountCache.list.getFirst(); /1m+iM^V
CountCache.list.removeFirst(); zTl,VIa3p
ps.setInt(1, cb.getCountId()); 6JeAXj1g+
ps.executeUpdate();⑴ KU Mk:5
c
//ps.addBatch();⑵ iA`.y9'2
} #)i+'L8
//int [] counts = ps.executeBatch();⑶ pcQkJF
conn.commit(); ,1.Td=lY$
}catch(Exception e){
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e.printStackTrace(); * bhb=~
} finally{ m?1r@!/y
try{ |VjD. ]I
if(ps!=null) { rmFcSolt,f
ps.clearParameters(); qP zxP @4
ps.close(); C1qlB8(Wh>
ps=null; |N3#of(
} >5TXLOYZ
}catch(SQLException e){} ^4p$@5zH
DBUtils.closeConnection(conn); ~]9EhC'l
} s$lJJL
} )c 79&S
public long getLast(){ Q4Qf/q;U
return lastExecuteTime; /%F,
} E8t{[N6d
public void run(){ tO D}&
long now = System.currentTimeMillis(); R((KAl]dL
if ((now - lastExecuteTime) > executeSep) { AM#s2.@
//System.out.print("lastExecuteTime:"+lastExecuteTime); M"msLz
//System.out.print(" now:"+now+"\n"); " ub0}p4V
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); PCa0I^d
lastExecuteTime=now; B5R 7geC
executeUpdate(); Z^%HDB9^
} ~zvZK]JoX
else{ y@AUSh;
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); `D$RL*C;M`
} `=Bv+
} -q
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} >7cDfv"
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 (.wR!l#!
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类写好了,下面是在JSP中如下调用。 1CJAFi>%D
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<% q$`>[&I~)
CountBean cb=new CountBean(); RX^Xtc"
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); F[)tg#}@G
CountCache.add(cb); 0bSnD|#I
out.print(CountCache.list.size()+"<br>"); VCIV*5
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CountControl c=new CountControl(); *<h )q)HS
c.run(); 8.7lc2aX
out.print(CountCache.list.size()+"<br>"); }KNBqPo4B
%>