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: vi` VK&+r
H%0WD_
CountBean.java szD9z{9"y
a'O-0]g,
/* X2{Aa T*M
* CountData.java ,o}CBB! k
* }/Qj8l.
* Created on 2007年1月1日, 下午4:44 H#G3CD2&
* >u]9(o7I
* To change this template, choose Tools | Options and locate the template under szXqJG8|
* the Source Creation and Management node. Right-click the template and choose V5gr-^E
* Open. You can then make changes to the template in the Source Editor. x+v&3YF
*/ 55=YM'5]
B_RF)meux
package com.tot.count; &AVX03P
g!Ui|]BI9
/** Bq,MTzxD
* WA.c.{w\
* @author j|{
n?
*/ COj^pdE3
public class CountBean { AqHGBH0
private String countType; KL"_h`UW
int countId; yh'*eli
/** Creates a new instance of CountData */ V{X/y N.u
public CountBean() {} _|#P~Ft
public void setCountType(String countTypes){ M|R\[
Zf
this.countType=countTypes; B7sBO6Z$J
} V6B[eV$D
public void setCountId(int countIds){ hsJGly5H
this.countId=countIds; @9l$jZ~x
} |hX\ep
public String getCountType(){ o\fPZ`p-m~
return countType; :_Iz(
2hV
} 3N4kW[J2i
public int getCountId(){ (3=bKcD'
return countId; ]ZH6
.@|
} s+ ^1\
} h?vny->uJ
uc LDl
CountCache.java A,c_ME+DVB
|nU%H=Rs/
/* 5acC4v!T
* CountCache.java
$QwzL/a
* AdbTI#eY
* Created on 2007年1月1日, 下午5:01 *%%n9T
* 5C9
.h:c4y
* To change this template, choose Tools | Options and locate the template under h!tg+9%
* the Source Creation and Management node. Right-click the template and choose X^i3(N
* Open. You can then make changes to the template in the Source Editor. w:](F^<s,
*/ #c9MVQ_
O9RnS\
package com.tot.count; #%{
import java.util.*; w^:@g~
/** [Scao $
* i_nUyH%b
* @author =FMrVE
*/ ]deO\mB
public class CountCache { 2} _^~8
public static LinkedList list=new LinkedList(); Z1p%6f`
/** Creates a new instance of CountCache */ 3wQ\L=
public CountCache() {} @P h'!
public static void add(CountBean cb){ s"~,Zzy@j
if(cb!=null){ y^ D3}ds
list.add(cb); i%MR<M
} CY"i|s
} [a.(0YLr'w
} g@]1H41
\aN5:Yy
CountControl.java ClufP6'
}:*?w>=
/* N9vNSmm
* CountThread.java yr)e."#S
* W k "_lJ
* Created on 2007年1月1日, 下午4:57 ,t|_Nc
* w1
A-_
* To change this template, choose Tools | Options and locate the template under ~se
;L
* the Source Creation and Management node. Right-click the template and choose mXu";?2
* Open. You can then make changes to the template in the Source Editor. swMR+F#u*
*/ 89W8cJ$yW
^5+7D1>W%
package com.tot.count; QRF:6bAxsL
import tot.db.DBUtils; Ko
"JH=<
import java.sql.*; *48LQzc
/** J+`gr_&
* 5oOs.(m|*C
* @author "AIS6%,
*/ i6i;{\tc
public class CountControl{ 9gZS)MZ
private static long lastExecuteTime=0;//上次更新时间 v4\
m9Pu4
private static long executeSep=60000;//定义更新间隔时间,单位毫秒
\P*%u
/** Creates a new instance of CountThread */ 7e{w,.ny!
public CountControl() {} N8!e(YK_
public synchronized void executeUpdate(){ lg@q}
]1
Connection conn=null; .SBN^fq
PreparedStatement ps=null; ]ij:>O@{$
try{ Mi`t$hmP
conn = DBUtils.getConnection(); GB}X
conn.setAutoCommit(false); GF0Utp:Zf;
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); (unJwh{7Q
for(int i=0;i<CountCache.list.size();i++){ zj=F4]w
CountBean cb=(CountBean)CountCache.list.getFirst(); /#}%c'
CountCache.list.removeFirst(); s3~6[T?8
ps.setInt(1, cb.getCountId()); N9z!-y'X
ps.executeUpdate();⑴ f&XM|Bg
//ps.addBatch();⑵ (e3?--~b6
} /|<0,oz oJ
//int [] counts = ps.executeBatch();⑶ r?`7i'
conn.commit(); x
o72JJ
}catch(Exception e){ ^AO2%09.S
e.printStackTrace(); 0%3T'N%
} finally{ Tn$|
Xa+:s
try{ lPz5.(5'
if(ps!=null) { ]O~/k~f
ps.clearParameters(); ;bq
EfV0`2
ps.close(); XsMETl"Av4
ps=null; Z3iX^
} CS"p3$7,
}catch(SQLException e){} ~>}7+p
?;
DBUtils.closeConnection(conn); ?[lKft
} 11JO [
} @T sdgx8
public long getLast(){ KpO%)M!/Z#
return lastExecuteTime; [wJl]i
} v2mqM5Z
public void run(){ 2f9%HX(5
long now = System.currentTimeMillis(); u?8e>a
if ((now - lastExecuteTime) > executeSep) { ;fv/s]X86I
//System.out.print("lastExecuteTime:"+lastExecuteTime); E8We2T[^M
//System.out.print(" now:"+now+"\n"); K]i2$M
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); o4,m+:
lastExecuteTime=now; _?>f9K$1
executeUpdate(); l"
H/PB<.
} l,Ixz1S3e
else{ N37#Vs
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 6r)qM)97
} Rs 0Gqx
} GZ"J6/0-|
} \JZ'^P$Q
//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 , pr ",=
~Q1%DV.
类写好了,下面是在JSP中如下调用。 65pC#$F<x
fOO[`"'Pq
<% eadY(-4|I-
CountBean cb=new CountBean(); @nF#\
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); :*lB86Ly
CountCache.add(cb); -Cf<
#'x_
out.print(CountCache.list.size()+"<br>"); YZ+<+`Mz<
CountControl c=new CountControl(); f.u[!T
c.run(); I*8_5?)g<
out.print(CountCache.list.size()+"<br>"); 3 jay V
%>