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: I@\+l6&#;
,l HLH
CountBean.java {)@D`{$
m`6VKp{YD
/* [i7YVwG4
* CountData.java qu~X.pW
* zizk7<?L.
* Created on 2007年1月1日, 下午4:44 lY'N4x7n
* rk|@B{CA;
* To change this template, choose Tools | Options and locate the template under }`o?/!X
* the Source Creation and Management node. Right-click the template and choose p|qyTeg
* Open. You can then make changes to the template in the Source Editor. ;YyXT"6/p
*/ rh%m;i<b
`8:K[gp
package com.tot.count; $`ztiVu3
?6P.b6m}0
/** jL>:>r
* 1 ] #9
* @author K
|*5Kwi
*/ OBOwz4<
public class CountBean { T_;]fPajjD
private String countType; WeMAe
w/d
int countId; R7?29?$7
/** Creates a new instance of CountData */ A:# k
public CountBean() {} DBs DkkB{
public void setCountType(String countTypes){ M#,Q
^rH#
this.countType=countTypes; j6g@tx^)'
} 8=;k"
public void setCountId(int countIds){ zY=jXa)K~
this.countId=countIds; OH6^GPF6
} 7:Ztuc]
public String getCountType(){ ?=Db@97
return countType; O#eZ<hNV
} \we\0@v
public int getCountId(){ ?&X6:KJQ
return countId; 0CAa^Q^w
} SVWIEH0?
} $t/rOo9cV
9&Ne+MY^%
CountCache.java d]wD[]
?+2b(2&MXE
/* PmX2[7
* CountCache.java '#\1uXM1U?
* h<6UC%'ac
* Created on 2007年1月1日, 下午5:01 U|@V
74
* h7yqk4'Lq
* To change this template, choose Tools | Options and locate the template under Ev9> @~^
* the Source Creation and Management node. Right-click the template and choose }-DE`c
* Open. You can then make changes to the template in the Source Editor. izZ=d5+K
*/ D'_Bz8H!p
h|;qG)f^
package com.tot.count; {i [y9
import java.util.*; %.HJK
/** zsXpA0~3s
* E JK0
* @author #8h;Bj
*/ r8/l P}(F
public class CountCache { c EnkU]
public static LinkedList list=new LinkedList(); FjFMR
63
/** Creates a new instance of CountCache */ BR5BJX
public CountCache() {} LT@OWH
public static void add(CountBean cb){ x/fX`y|(}*
if(cb!=null){ jd-glE,Y/
list.add(cb); K^[#]+nQ
} LnsD
} Ao9R:|9
}
CE%_A[a
%O[N}_XHEh
CountControl.java kv{}C)kt3
?>
Dtw#}
/* g);^NAA
* CountThread.java hJ;$A*Y
* EbY,N:LK
* Created on 2007年1月1日, 下午4:57 3ec`Wa
* iw9Q18:I}
* To change this template, choose Tools | Options and locate the template under s5&@Cxzl
* the Source Creation and Management node. Right-click the template and choose `~BZ1)@
* Open. You can then make changes to the template in the Source Editor. ,e722wz
*/ ~x:DXEV,
w.{&=WTr
package com.tot.count; m#!=3P7T
import tot.db.DBUtils; YB( Gk;]
import java.sql.*; Qdk6Qubi!
/** BU Z
_)
* H^%lDz
* @author :[l\@>H1tX
*/ .Ajzr8P
public class CountControl{ R`8@@}
private static long lastExecuteTime=0;//上次更新时间 .="bzgC3A
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 9!',b>C6
/** Creates a new instance of CountThread */
!YL..fb
public CountControl() {} XOP"Px@
public synchronized void executeUpdate(){ hfWFD,
Connection conn=null; `>C<}xO
PreparedStatement ps=null; <UP
m=Hb
try{ 7,
}
$u
conn = DBUtils.getConnection(); 8IQtz2
conn.setAutoCommit(false); feM6K!fL`
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ZP\M9Ja
for(int i=0;i<CountCache.list.size();i++){ bm~W
EX
CountBean cb=(CountBean)CountCache.list.getFirst(); =wWpP-J&
CountCache.list.removeFirst(); {Ro2ouQ!V
ps.setInt(1, cb.getCountId()); s^Nw%KAv
ps.executeUpdate();⑴ - YqYcer
//ps.addBatch();⑵ b}^S.;vNj
} d*8 $>GA
//int [] counts = ps.executeBatch();⑶ @$^bMIj@W
conn.commit(); DTRJ/@t
}catch(Exception e){ o G*5f
e.printStackTrace(); G3P&{.v
} finally{ /6uT6G+(z}
try{ "I6P=]|b
if(ps!=null) { &)wiKh"$
ps.clearParameters(); I=)hWC/
ps.close(); 3g'S\G@
ps=null; %8~Q!=*Iq
} x&sI=5l
}catch(SQLException e){} S{t +>/
DBUtils.closeConnection(conn); IY'=DePd
} `>Tu|3%\
} f"G-
public long getLast(){ CvSIV7zYo
return lastExecuteTime; 8`>h}Q$
} 5zJj]A
public void run(){ &F:IIo7
long now = System.currentTimeMillis(); "Mw[P [w*
if ((now - lastExecuteTime) > executeSep) { 7"F*u :
//System.out.print("lastExecuteTime:"+lastExecuteTime); Ks^6.)
//System.out.print(" now:"+now+"\n"); Y_&g="`Q
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ?lGG|9J\
lastExecuteTime=now; F_iXd/
executeUpdate(); -&x2&WE'
} GE;e]Jkjn
else{ rEhX/(n#
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); H={DB
} \J. .*,'
} 9_s6l
} :o-,SrORM
//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 E:sz$\Ht)
:K`ESq!8u
类写好了,下面是在JSP中如下调用。 RoA?p;]<
W:,4 :|3
<% <~ad:[
CountBean cb=new CountBean(); 6fH@wQ"wN
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ^H{R+}
CountCache.add(cb); (/!r(#K0,'
out.print(CountCache.list.size()+"<br>"); #4MBoN(3
CountControl c=new CountControl(); ~LJY6A@y
c.run(); :P,sxDlG)
out.print(CountCache.list.size()+"<br>"); O<PO^pi
%>