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: b3/@$x<
L<t>o":o
CountBean.java n$2IaE;v
F52%og~N
/* zD#$]?@ b
* CountData.java k|C~qe3E
* icO$9c
* Created on 2007年1月1日, 下午4:44 {e'P*j
* ~lBb%M
* To change this template, choose Tools | Options and locate the template under 6Zr_W#SE
* the Source Creation and Management node. Right-click the template and choose OQlmzg
* Open. You can then make changes to the template in the Source Editor. l ga%U~
*/ 0 ge"ISK
[&_7w\m
package com.tot.count; -cgLEl1 J
6MCLm.L
/** d#-scv}s5
* :n#8/'%1
* @author #$5"&SM
*/ ;(&$Iw9X
public class CountBean { X8}m
%
private String countType; WqX$;'}h
int countId; UL{+mp
/** Creates a new instance of CountData */ 0+-"9pED>E
public CountBean() {} 1c5+XCr
public void setCountType(String countTypes){ pZE}<EX
this.countType=countTypes; ro& /
} 'E\/H17
public void setCountId(int countIds){ .Us)YVbk
this.countId=countIds; HZINsIm!?
} {l
E\y9
public String getCountType(){ 0W_olnZ
return countType; 2XX-
} ]\~s83?X
public int getCountId(){ u%t/W0xi
return countId; .O yzM
} c-GS:'J{
} ABx< Ep6
lfJvN
CountCache.java c
-sc*.&
8+*
1s7{
/* v}cTS@0
* CountCache.java ?\Bm>p%+
* p*NKM}
]I
* Created on 2007年1月1日, 下午5:01 MG}rvzn@
* V=i/cI\
* To change this template, choose Tools | Options and locate the template under D`Cy]j
* the Source Creation and Management node. Right-click the template and choose GhJ<L3
* Open. You can then make changes to the template in the Source Editor. Y>J$OA:
*/ q1a*6*YB
T`zUgZ]
package com.tot.count; x/S:)z%X
import java.util.*; e 2"<3
/** WMw|lV r
* C
vOH*K'
* @author >g>L>{
*/ +#RgHo?f
public class CountCache { =(==aP
public static LinkedList list=new LinkedList(); }5Zmc6S{
/** Creates a new instance of CountCache */ kTW[)
public CountCache() {} 3>T2k }
public static void add(CountBean cb){ A"3"f8P8a
if(cb!=null){ gmqL,H#
list.add(cb); [PIh^DhK
} 5cF7w
} QmKEl|/{u
} nk*T
x
Al
MMN"j
CountControl.java _:1s7EC
tLE7s_^
/* ,q K'!
* CountThread.java On~w`
* c{"qrwLA
* Created on 2007年1月1日, 下午4:57 5y~Srb?2
* @oNYMQ@)d
* To change this template, choose Tools | Options and locate the template under T5_/*`F
* the Source Creation and Management node. Right-click the template and choose mgd)wZNV
* Open. You can then make changes to the template in the Source Editor. !'z"V_x~
*/ p
2>\
l!*!)qCB(S
package com.tot.count; &*Z"r*
import tot.db.DBUtils; Z?f-_NHg
import java.sql.*; O}-+o 1
/** shZEE2Dr
* "$I8EW/1
* @author )p`zN=t
*/ <~bvfA=
public class CountControl{ ;%Zu[G`C
private static long lastExecuteTime=0;//上次更新时间 MqAN~<l [
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 'PvOOhm,
/** Creates a new instance of CountThread */ Mp3nR5@d$
public CountControl() {} K'c[r0Ew
public synchronized void executeUpdate(){ Vr7L9%/wg
Connection conn=null; I_s* pT
PreparedStatement ps=null; 4n0Iw I
try{ Krd0Gc~\|
conn = DBUtils.getConnection(); wBlo2WY
conn.setAutoCommit(false); ;S?ei>Q
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 1>=]lMW
for(int i=0;i<CountCache.list.size();i++){ mVd%sWD
CountBean cb=(CountBean)CountCache.list.getFirst(); K2qKkV@
CountCache.list.removeFirst(); P,s>xM
ps.setInt(1, cb.getCountId()); M nnVk=
ps.executeUpdate();⑴ WkMB
//ps.addBatch();⑵ P_.zp5>
} o_sb+Vn|
//int [] counts = ps.executeBatch();⑶ 4*&2D-8<K
conn.commit(); fyF8RTm{
}catch(Exception e){ xyrlR;Sk
e.printStackTrace(); SUb:0GUa
} finally{ ,Ma%"cWVC
try{ NtG^t}V
if(ps!=null) { `D? &)Y
ps.clearParameters(); q\G7T{t$.
ps.close(); V4ybrUWK
ps=null; LlcH#L$
} 3z0%uY[e
}catch(SQLException e){} nC}Y+_wo0
DBUtils.closeConnection(conn); G.:QA}FE'
} +F92_a4
} n
>@Qx$-
public long getLast(){ ROJ=ZYof
return lastExecuteTime; cKB1o0JsYJ
} ckkm}|&m
public void run(){ ID~}pEQ
long now = System.currentTimeMillis(); fD*jzj7o,
if ((now - lastExecuteTime) > executeSep) { &S=xSs:q.
//System.out.print("lastExecuteTime:"+lastExecuteTime); >{{0odBF
//System.out.print(" now:"+now+"\n"); x3l~k Z(
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); qm6 X5T
lastExecuteTime=now; KjK-#F,@
executeUpdate(); iBk1QRdn
} #'5{
?Cb
else{ 629ogJo8
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); &3|l4R\
} (z:qj/|
} "XLFw;o
} 1b<[/g9
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 t+#vcg,G
b/d1(B@
类写好了,下面是在JSP中如下调用。 Tq,dlDDOR
-#Jp@6'k%
<% lvH} 8lJ
CountBean cb=new CountBean(); G4^6o[ x
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); i|xC#hV
CountCache.add(cb); !
Q8y]9O
out.print(CountCache.list.size()+"<br>"); L5wR4Ue)
CountControl c=new CountControl(); P@0J!
c.run(); ?&D.b$
out.print(CountCache.list.size()+"<br>"); +ZR>ul-c
%>