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: eFipIn)b
y~(h>gi,x
CountBean.java Y&`=jDI
W'els)WJ|x
/* PYQ;``~x
* CountData.java W=lyIb{?^0
* mD/9J5:
* Created on 2007年1月1日, 下午4:44 @efh{
* "_P;2N6
* To change this template, choose Tools | Options and locate the template under 0*VWzH
* the Source Creation and Management node. Right-click the template and choose q$p%ZefZ
* Open. You can then make changes to the template in the Source Editor. ) g0%{dfJ
*/ Y$o<6[7
>u>5{4
package com.tot.count; )S3\,S-.
"Hya6k>j
/** IO wj>t
* 9K.Vb1&
* @author 1Vsz4P"O $
*/ A_V]yP
public class CountBean { ]E7F/O/.
private String countType; 3^IpE];+:u
int countId; Gq+z /Be
/** Creates a new instance of CountData */ f W!a|?e$
public CountBean() {} Y5f1lUT
public void setCountType(String countTypes){ Q}`0W[a
~
this.countType=countTypes; @>u}eB>Kn
} ,NOsFO-`<
public void setCountId(int countIds){ ~Io7]
this.countId=countIds; j_/>A=OD
} *lYVY)L
public String getCountType(){ -^K"ZP1
return countType; Amp#GR1CA
} y?rPlA_
public int getCountId(){ \j+1V1t9
return countId; )5rb&M}
} tG:25 T0
} .>q8W
.rO]M:UY
CountCache.java S3F;(PDzy
C](f>)Dz
/
/* dFRsm0T
* CountCache.java 6RG)`bu
* iyA'#bE-
* Created on 2007年1月1日, 下午5:01 VQ"hUX8
* :=}BN
* To change this template, choose Tools | Options and locate the template under .@2m07*1
* the Source Creation and Management node. Right-click the template and choose XQ#;Zs/l
* Open. You can then make changes to the template in the Source Editor. P !AEf#1
*/ 3("_Z%
f6EZ(
v
package com.tot.count; \"qY "V
import java.util.*; Vl5`U'^qx
/** b v G/|U
* t
4PK}>QW
* @author bhID#&
*/ .O74V~T
public class CountCache { pqk?|BvpK_
public static LinkedList list=new LinkedList(); H0:E(}@
/** Creates a new instance of CountCache */ gGvz(R:y
public CountCache() {} c*(bO3 b
public static void add(CountBean cb){ |^0XYBxQ
if(cb!=null){ H]P.
x!I
list.add(cb); J
cPtwa;q@
} *,3SGcYdJj
} D~biKrg?=
} [6 pD
pN!}UqfI-
CountControl.java 'ZT^PV\
1Y/s%L
/* +vvv[
* CountThread.java ;QWIsVz
* dpJ_r>NI
* Created on 2007年1月1日, 下午4:57 m/Oh\KlIl
* 4 kn|^
* To change this template, choose Tools | Options and locate the template under (g EBOol
* the Source Creation and Management node. Right-click the template and choose N<|@ymi
* Open. You can then make changes to the template in the Source Editor. kEJj=wx
*/ .GV;+8HzS
zepm!JR1
package com.tot.count; x%}^hiO<q
import tot.db.DBUtils; ,">]`|?
import java.sql.*;
7_%"BVb"
/** {`J)j6;
* Hv!U|L
* @author 7/!8e.M\
*/ 'r4/e-`pK
public class CountControl{ ]*vdSr-J
private static long lastExecuteTime=0;//上次更新时间 j`oy`78O
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 tU4s'J
/** Creates a new instance of CountThread */ 3XL#0\im?s
public CountControl() {} Qr1 "Tk7s
public synchronized void executeUpdate(){ ~Am,%"%\
Connection conn=null; Cf TfL3(J
PreparedStatement ps=null; ~KHVY)@P
try{ O9vQp
conn = DBUtils.getConnection(); 5pj22 s
conn.setAutoCommit(false); E'G4Y-
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); N8k00*p65
for(int i=0;i<CountCache.list.size();i++){ 6 2'j!"xv
CountBean cb=(CountBean)CountCache.list.getFirst(); >v:y?A,
CountCache.list.removeFirst();
5Ec6),+&
ps.setInt(1, cb.getCountId()); {F3xJ[
ps.executeUpdate();⑴ prYs
$j
//ps.addBatch();⑵ oT^{b\XN
} 5XO;N s
//int [] counts = ps.executeBatch();⑶ ./,/y"x
conn.commit(); lm!.W5-l
}catch(Exception e){ mZk]l5Lc
e.printStackTrace(); ,ek_R)&[o
} finally{ D6%J\C13`
try{ c0PIc^R(@
if(ps!=null) { |*:'TKzNS
ps.clearParameters(); mX_a^_[G
ps.close(); ^.KwcXr
ps=null; ?>hPO73{
} 8s"%u )
}catch(SQLException e){} Q(lo{AFc
DBUtils.closeConnection(conn); K&bzDzd `
} 4^TG>j?M
} L_vISy%\b
public long getLast(){ >Nvjl~o5
return lastExecuteTime; 6""G,"B
} wN`jE0
{
public void run(){ ]j'p :v
long now = System.currentTimeMillis(); PRr2F-!P
if ((now - lastExecuteTime) > executeSep) { DKne'3pH
//System.out.print("lastExecuteTime:"+lastExecuteTime); TFH \K{DM
//System.out.print(" now:"+now+"\n"); mk1bcK9
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); DSC$i|
lastExecuteTime=now; :e]a$
executeUpdate(); QcgRAo+u
} *i]=f6G
else{ 1xD=ffM>8N
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); WfWN(:dF
} "^4_@ oo
} t\NqR
} ?kWC}k{
//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 |?rNy=P,
21
O'M
类写好了,下面是在JSP中如下调用。 .P;*D ws
KB%"bqB|
<% r
YogW!
CountBean cb=new CountBean(); &0='r;*i
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 3|WWo1
CountCache.add(cb); !u_Y7i3^
out.print(CountCache.list.size()+"<br>"); }lh I\q
CountControl c=new CountControl(); &S( .GdEf
c.run(); VSrr`B
out.print(CountCache.list.size()+"<br>"); }2<r,
%>