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: }g%KvYB_
2Px$0&VN
CountBean.java 6#OL
;Y]_
L7i}Ga!8
/* M@',3
* CountData.java +3NlkN#
* L*kh?PS;
* Created on 2007年1月1日, 下午4:44 o+]Y=r2
* KyuA5jQ7
* To change this template, choose Tools | Options and locate the template under :;" aUHU'
* the Source Creation and Management node. Right-click the template and choose e{^:/WcYB
* Open. You can then make changes to the template in the Source Editor. TBoM{s=.
*/ ^4y(pcD
D[?k ,*
package com.tot.count; 2r PcNh9
2P;%P]~H
/** {^PO3I
* B2ek&<I7N
* @author hj[+d%YZY"
*/ cq'}2pob
public class CountBean { lM@<_=2
private String countType; Q0
uP8I}n
int countId; w>`h3;,2
/** Creates a new instance of CountData */ T% /xti5$!
public CountBean() {} 2<46jJYL'
public void setCountType(String countTypes){ VJ~X#Q
this.countType=countTypes; 1q}u?7nnSG
} aTL8l.c2
public void setCountId(int countIds){ kg/+vJ
this.countId=countIds; E<X{72fb>
} N$=(1`zM=
public String getCountType(){ fg>B
return countType; O<eWq]
} Mp^OL7p^^
public int getCountId(){
l0:e=q2Ax
return countId; AHp830\
} .-O@UQx.I
} p]1yd;Jt
Ef,7zKG
CountCache.java 2yEO=SN,(
zAkc67:
/* .pB8=_e:
* CountCache.java KG4#BY&^
* "2#-xOCO
* Created on 2007年1月1日, 下午5:01 pr[B$X.V
* (T%F!2i([U
* To change this template, choose Tools | Options and locate the template under #Vn>ue+?
* the Source Creation and Management node. Right-click the template and choose sT[av
* Open. You can then make changes to the template in the Source Editor. @^y?Bh9jQ
*/ /A[oj2un
[G'!`^V,
package com.tot.count; q5'yD;[hE
import java.util.*; </+%R"`
/** w$(0V$l_
* H/p-YtY
* @author Wd^F%)(
*/ 23(E3:.
public class CountCache { xtIehr0{$I
public static LinkedList list=new LinkedList(); U&]p!DV&;
/** Creates a new instance of CountCache */ :EQme0OW
public CountCache() {} cAKoPU>U
public static void add(CountBean cb){ V ~J2s
if(cb!=null){ ?5r2j3mqgv
list.add(cb); \AtwO
} evg 7d
} FVC2 XxP
} f9l<$l
\: _.N8"
CountControl.java {!{7zM%u0C
$cJN9|$6
/* g+KzlS[6
* CountThread.java \@}$Wjsl
* bE`*Uw4
* Created on 2007年1月1日, 下午4:57 +/b4@B7
* G2yUuyAZ
* To change this template, choose Tools | Options and locate the template under [b
k&Nd[
* the Source Creation and Management node. Right-click the template and choose &x0TnW"g
* Open. You can then make changes to the template in the Source Editor. +U_-Lq )
*/ <zDw&s2
Y?vm%t`K
package com.tot.count; P8,{k
import tot.db.DBUtils; <v7KE*#
import java.sql.*; {DXZ}7w:v
/** 9+is?Pj
* Am0.c0h
* @author 'd.@4 9
*/ tzW<&^
public class CountControl{ ad$Qs3)6o
private static long lastExecuteTime=0;//上次更新时间 ^; V>}08
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 :UhFou_D4l
/** Creates a new instance of CountThread */ #HnyE+tD
public CountControl() {} SJ[@fUxO)
public synchronized void executeUpdate(){ xu?QK6D:
Connection conn=null; b
gc<)=
PreparedStatement ps=null; ;&^"q{m
try{ j3[OY
conn = DBUtils.getConnection(); ^? {kj{v
conn.setAutoCommit(false); h%w\O Z7
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 2E;%=e
for(int i=0;i<CountCache.list.size();i++){ ZesD(
CountBean cb=(CountBean)CountCache.list.getFirst(); t`1]U4s&I
CountCache.list.removeFirst(); \IZ4( Z
ps.setInt(1, cb.getCountId()); q' V{vFfY%
ps.executeUpdate();⑴ Ah>krE0t
//ps.addBatch();⑵ vS t=Ax3]
} O+o%C*`K
//int [] counts = ps.executeBatch();⑶ ^$Io;*N4
conn.commit(); mV(x&`Cx
}catch(Exception e){ ihBl",l&Hq
e.printStackTrace(); IV)W|/.
} finally{ ccRk4xR
try{ D_ZBx+/_?
if(ps!=null) { Lr\ B
ps.clearParameters(); p vR& ~g
ps.close(); *,[=}v1
ps=null; !6/IKh`J
} &CmkNm_B
}catch(SQLException e){} S w(
H]
DBUtils.closeConnection(conn); |AfQ_iT6c
} .x$T al
} u[|S*(P
public long getLast(){ QRHm|f9_C
return lastExecuteTime; 8'xnhV
} fG$.DvJuK
public void run(){ JiLrwPex[
long now = System.currentTimeMillis(); f$W}d0(F;
if ((now - lastExecuteTime) > executeSep) { s]%!
//System.out.print("lastExecuteTime:"+lastExecuteTime); Qn3+bF4
//System.out.print(" now:"+now+"\n"); FC(cXPX}
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); KC-aLq/
lastExecuteTime=now; DJ[#H
executeUpdate(); +}0*_VW
} Tc(v\|F,
else{ \q1%d.\X
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); $q$\GOQ 9
} j<P%Uy+
} RR[TW;
} !X <n:J
//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 7%!KAtc
BXv)zE=j
类写好了,下面是在JSP中如下调用。 a[cH@7W.#
GXK?7S0H
<%
q8bS@\i
CountBean cb=new CountBean(); [f(^vlK
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ;f^jB;\<
CountCache.add(cb); (a!,)
out.print(CountCache.list.size()+"<br>"); 64>[pZF8
CountControl c=new CountControl(); UnF4RF:A2&
c.run(); HbSx}bM_9
out.print(CountCache.list.size()+"<br>"); c] R![sa
%>