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"\-iY]
fR.raI4et
CountBean.java dd=5`Bo9Yh
]Gl_L7u`
/* ^R\5'9K!
* CountData.java e /XOmv
* Kc9)Lzu+
* Created on 2007年1月1日, 下午4:44 o\j<EQb.
* *=z.H
*
* To change this template, choose Tools | Options and locate the template under X pXhg*}K
* the Source Creation and Management node. Right-click the template and choose j@JY-^~K5
* Open. You can then make changes to the template in the Source Editor. -eSI"To L<
*/ 6O5E4=
i\36 s$\
package com.tot.count; [u3^R]
xT9+l1_
/** [t^%d9@t
* \@2sI
* @author ,38bT#p:,r
*/ /9y'UKl7[
public class CountBean { !x:w2
private String countType; `).;W
int countId; 0txSF^x
/** Creates a new instance of CountData */ lSId<v?C>
public CountBean() {} b=Sl`&A
public void setCountType(String countTypes){ mR{%f?B
this.countType=countTypes; d@|j>Z
} '9wD+'c=A
public void setCountId(int countIds){ S4O:?^28
this.countId=countIds; >|T?87
} XeBSHvO_
public String getCountType(){ ;`bJgSCfo
return countType; MD:kfPQ
} U|h@Pw z
public int getCountId(){ ,KibP_<%&P
return countId; a-TsD}'X
} "ZVBn!
} P3XP=G`E
( Gxv?\
CountCache.java D+_PyK~jc
1/qiE{NW
/* [laX~(ND{
* CountCache.java 0H.B>:pv
* kqAQrg]n
* Created on 2007年1月1日, 下午5:01 &sA6o"h~
* ~pSD| WX
* To change this template, choose Tools | Options and locate the template under &9] [~$
* the Source Creation and Management node. Right-click the template and choose .J\U|r
* Open. You can then make changes to the template in the Source Editor. >-y&k^a=
*/ El&pux2
A[':O*iB
package com.tot.count; &<i>)Ss
import java.util.*; U7fE6&g
/** l 0b=;^6
* >|I3h5\M
* @author N<Q}4%^c
*/ 4_I,wG@
public class CountCache { &(^>}&XS.<
public static LinkedList list=new LinkedList(); "Lpt@g[HF
/** Creates a new instance of CountCache */ vDOeBw=
public CountCache() {} IO_H%/v"jC
public static void add(CountBean cb){ XY QUU0R
if(cb!=null){ <ct {D|mm
list.add(cb); U14dQ=~b/
} $l[*Y
} 1@qb.9wZ6
} +Vf|YLbhJ
S(-=I!.G{
CountControl.java E 0pF; P5
C X'E+
/* 0Rk'sEX,
* CountThread.java 01q7n`o#zf
* 'Jl.fN
* Created on 2007年1月1日, 下午4:57 s3kEux^
* mg,f> (
* To change this template, choose Tools | Options and locate the template under .y2<2eW
* the Source Creation and Management node. Right-click the template and choose !V-SV`+X
* Open. You can then make changes to the template in the Source Editor. y<.!TULa_
*/ 7<:w-
17Gdu[E
package com.tot.count; S@"=,Xj M
import tot.db.DBUtils; K;xW/7?
import java.sql.*; ta 6WZu
/** ;qk~>
* w./EJkKI
* @author c`}X2u]k
*/ 22r01qH
public class CountControl{ FfgJ
2y
private static long lastExecuteTime=0;//上次更新时间 a!^wc,
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 xNqQbkF
/** Creates a new instance of CountThread */ G =4 y!y
public CountControl() {} Sf'5/9<DW+
public synchronized void executeUpdate(){ w+$gY?%
Connection conn=null; A>g$[
PreparedStatement ps=null; |uZ=S]V@
try{ gX _BJ6
conn = DBUtils.getConnection(); J+|ohA
conn.setAutoCommit(false); f8^58]wx0
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); @>:07]Dxo
for(int i=0;i<CountCache.list.size();i++){ PrKlwhi#
CountBean cb=(CountBean)CountCache.list.getFirst(); /#se>4]
CountCache.list.removeFirst(); NU(/Yit
ps.setInt(1, cb.getCountId()); h{xERIV1u
ps.executeUpdate();⑴ )Z%+~n3o'
//ps.addBatch();⑵ ipp_?5TL
} hCvn(f
//int [] counts = ps.executeBatch();⑶ yK7>^p}V
conn.commit(); _TXV{<E6
}catch(Exception e){ omA*XXUx=8
e.printStackTrace(); Y#Vy:x[
} finally{ G\p;
bUF
try{ rlIEch^wZ
if(ps!=null) { t3>rf3v
ps.clearParameters(); YPy))>Q>cK
ps.close(); G([vy#p
ps=null; @!'H'GvA
} #Fd([Zx#.
}catch(SQLException e){} bg*{1^
DBUtils.closeConnection(conn); (Sv%-8?gs
} KJ)&(Yx
} FVmg&[
.
public long getLast(){ XfrnM^oty
return lastExecuteTime; _dBU6U:V
} h*9o_
public void run(){ S+y2eP G
long now = System.currentTimeMillis(); =5M>\vt]
if ((now - lastExecuteTime) > executeSep) { dJ^`9W
//System.out.print("lastExecuteTime:"+lastExecuteTime); ?.4l1X6Ba
//System.out.print(" now:"+now+"\n"); .am*d|&+G
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ~=mM/@HD
lastExecuteTime=now; feW9>f;
executeUpdate(); p,8Z{mLn
} bN&da
[K
else{ VT7NWTJ,
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); "'#Hh&Us
} &Kp+8D*
} rw2|1_AF
} DS2$ w9!
//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 JrAc]=
"y0A<-~
类写好了,下面是在JSP中如下调用。 9.=#4OH/
\IfgL$+
<% (B-9M)
CountBean cb=new CountBean(); \8D~,$,``|
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ,R =VzP&
CountCache.add(cb); ~\G3l,4
out.print(CountCache.list.size()+"<br>"); Z :+#3.4$3
CountControl c=new CountControl(); 8!SiTOzR?
c.run(); __iyBaX
out.print(CountCache.list.size()+"<br>"); pb
Ie)nK
%>