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: D,'@b+B[
5nG$6Hw
CountBean.java 7o64|@ 'j
ZD]5"oHY
/* jhSc9
* CountData.java y]E ?\03"
* ,0[h`FN
* Created on 2007年1月1日, 下午4:44 uY=}w"Db
* F!yejn
[
* To change this template, choose Tools | Options and locate the template under ?gOZY\[ma
* the Source Creation and Management node. Right-click the template and choose .e%B'
* Open. You can then make changes to the template in the Source Editor. U}<;4Px]7v
*/ $`/J
V?Z
:ugj+
package com.tot.count; >=U n=Q%
g\
p;
/** Z(-@8=0
* HzF]hm,
* @author tr\}lfK%
*/ DvvjIYB~
public class CountBean { u-E*_%y
private String countType; KcX] g*wy
int countId; g4*]R>f
/** Creates a new instance of CountData */ 20H$9M=}
public CountBean() {} vZpt}u
public void setCountType(String countTypes){ *a4nd_!
this.countType=countTypes; Y$?<y
} slMWk;fmD}
public void setCountId(int countIds){ `ynD-_fTN
this.countId=countIds; ?I.<mdhN#t
} ,~-
dZs
public String getCountType(){ skP2IMa75
return countType; !B{N:?r
} CEos`
public int getCountId(){ KBo/GBD]|
return countId; nr<&j#!L
} hUy\)GsT
} j5;eSL@/
K"r'w8P
CountCache.java S_B;m1
htGk:
/* y2eeE CS]
* CountCache.java f^f{tOX
* n.$wW
=
* Created on 2007年1月1日, 下午5:01
T!N,1"r
* nAJ<@a
* To change this template, choose Tools | Options and locate the template under <w d+cPZQr
* the Source Creation and Management node. Right-click the template and choose kiFTx
&gf
* Open. You can then make changes to the template in the Source Editor. 7:t
*&$
*/ e'uI~%$NJL
ye)CfP=ID\
package com.tot.count; ?5!>k^q
import java.util.*; G6(U\VFqO
/** ;yO7!{_
* +<P%v k
* @author ')/yBH9mR
*/ 2*K _RMr~
public class CountCache { 7.PG*q
public static LinkedList list=new LinkedList(); wZm=h8d
/** Creates a new instance of CountCache */ )_nc;&%w
public CountCache() {} n1xN:A
public static void add(CountBean cb){ "p~1|?T
if(cb!=null){ QviH+9
list.add(cb); s:y=X$&M
} *a7&v3X
} Svo gvn
} u;Q'xuo3
RvF6bIqo
CountControl.java T.zUerbO
CKv[E
/* 8*^Q#;^~99
* CountThread.java F? kW{,*
* T&=1IoOg
* Created on 2007年1月1日, 下午4:57 #eT{?_wM
*
Z\d7dbv
* To change this template, choose Tools | Options and locate the template under MhZT<6
* the Source Creation and Management node. Right-click the template and choose Ncu\;K\N
* Open. You can then make changes to the template in the Source Editor. Ii,Lj1Q
*/ u"\HBbBx
Q2)z1'Wv
package com.tot.count; dM(}1%2
import tot.db.DBUtils; 4#Fz!Km
import java.sql.*; ruLi
"d
/** KF|<A@V
* UNJ]$x0
* @author x62b=k}
*/ V11Zl{uOl
public class CountControl{ Fa$ pr`
private static long lastExecuteTime=0;//上次更新时间 qsUlfv9L6
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 zR_#c3o
/** Creates a new instance of CountThread */ !tT$}?Ano
public CountControl() {} D^Bd>Ey4
public synchronized void executeUpdate(){ 1Ig@gdmz
Connection conn=null; j1)HIQE|5f
PreparedStatement ps=null; "|S \J5-%
try{ aUN!Sd2,
conn = DBUtils.getConnection(); ; 9pOtr
conn.setAutoCommit(false); ~B%=g)w
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); VrA9}"1x~*
for(int i=0;i<CountCache.list.size();i++){ \ qc8;"@
CountBean cb=(CountBean)CountCache.list.getFirst(); 33_YZOy^j
CountCache.list.removeFirst(); 6<+R55
ps.setInt(1, cb.getCountId()); 8]Xwj].^C
ps.executeUpdate();⑴ G l=dL<F
//ps.addBatch();⑵ `7P4O
} L\8tqy.
//int [] counts = ps.executeBatch();⑶ ~\c]!%)o
conn.commit(); qTnfiYG}
}catch(Exception e){ zlmb_akJ
e.printStackTrace(); 2yhtJ9/
} finally{ [EDw0e
try{ >8~+[e
if(ps!=null) { Lnnl++8Y
ps.clearParameters(); `RUr/|S
ps.close(); cjf}yn
ps=null; "PBUyh-Z
} zm}4=Kz}
}catch(SQLException e){} ip4:px-
DBUtils.closeConnection(conn); &_
Ewu@4
} ^.F@yo2}
} g83!il\
public long getLast(){ ]BU,*YaB
return lastExecuteTime; 7'_zJI^
} AG2iLictv
public void run(){ MPMJkL$F^
long now = System.currentTimeMillis(); Z'PE^ ,
if ((now - lastExecuteTime) > executeSep) { l
tr=_
//System.out.print("lastExecuteTime:"+lastExecuteTime); KE+y'j#C3
//System.out.print(" now:"+now+"\n"); 8@|_];9#.
// System.out.print(" sep="+(now - lastExecuteTime)+"\n");
>b#z
o,
lastExecuteTime=now; qx<`Kc4
executeUpdate(); lztPexyXZ
} KL!k'4JNY
else{ P8e1J0A
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); W?!(/`J]
} x2.G1
} e
=Vu;
} EVMhc"L
//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 ]`&EB~K&NY
*A`hKx
类写好了,下面是在JSP中如下调用。 |QJ!5nb
Z.$ncP0s
<% ^:K"Tv.=
CountBean cb=new CountBean(); !'Xk=+
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); zr?%k]A%UO
CountCache.add(cb); mCe,(/>l+
out.print(CountCache.list.size()+"<br>"); v8,+|+3
CountControl c=new CountControl(); *KF:
c.run(); oYnA 3
out.print(CountCache.list.size()+"<br>"); _/ZIDIn
%>