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: AlX3Wv}
YMzBAf
CountBean.java (F5ttQPh
,)#.a%EKA
/* -Zy)5NB-tZ
* CountData.java Jq1 n0O
* vDDljQXw4
* Created on 2007年1月1日, 下午4:44 7 `Du5>b8
* R}%8s*
* To change this template, choose Tools | Options and locate the template under 0D3OE.$0
* the Source Creation and Management node. Right-click the template and choose WmVVR>0V|
* Open. You can then make changes to the template in the Source Editor. z^`]7i
*/ ~
=.CTm]vf
qo;)X0N
package com.tot.count; Mtp%co )f
P;U@y"s
/** F=Y S^
* )x\z@g
* @author &HF]\`RNr
*/ ^Q2ZqAf^a
public class CountBean { +VOb
private String countType; UKs$W`
int countId; Slx2z%'>
/** Creates a new instance of CountData */ e- 6(F4
public CountBean() {} .ZX2^)`XD
public void setCountType(String countTypes){ uBeNXOre
this.countType=countTypes; Y mDn+VIg
} K`(#K#n
public void setCountId(int countIds){ rO^xz7K^
this.countId=countIds; P\(30
} L8P36]>
public String getCountType(){ $c=&0yt5
return countType; $9H[3OZPVv
} 1uM/2sX
public int getCountId(){ _Ex?Xk
return countId; pGkef0p@
} qS]G&l6QF
} chLeq
!;WbOnLP
CountCache.java WOb8"*OM
Wem?{kx0
/* Bbs 0v6&,
* CountCache.java 2oB?Dn
* <.$,`m,
* Created on 2007年1月1日, 下午5:01 4x]NUt
* 6Ct0hk4
* To change this template, choose Tools | Options and locate the template under VM;g+RRq
* the Source Creation and Management node. Right-click the template and choose .0
X$rX=
* Open. You can then make changes to the template in the Source Editor. m/?h2McS
*/ <9N4"d!A
?*o;o?5s^
package com.tot.count; Fwv\ pJ}$
import java.util.*; =ZMF ]|
/** |_I[1%&`N
* }200g_^
* @author BHclUwj
*/
2}!R
T
public class CountCache { L9J;8+ge
public static LinkedList list=new LinkedList(); enPYj.*/0
/** Creates a new instance of CountCache */ %mmxA6I
public CountCache() {} D(@SnI+
public static void add(CountBean cb){ ]ut?&&*
if(cb!=null){ hXnw..0"
list.add(cb); y4r2}8fi
} 24O
d] f
} !Sfe{/$w
} B3.X}ys#
I1v@\Rb
CountControl.java 1:5P%$?b
w 3d\0ub
/* At|ht
* CountThread.java ChVY
Vx(
* )BpIxWd?
* Created on 2007年1月1日, 下午4:57 d3(+ztmG!
* x{j+}'9
* To change this template, choose Tools | Options and locate the template under :SdIU36
* the Source Creation and Management node. Right-click the template and choose oE 5;|x3
* Open. You can then make changes to the template in the Source Editor. PbQE{&D#
*/ 'Ye]eL,I\
<L%HG
package com.tot.count; P;>!wU~*
import tot.db.DBUtils; &gJW6<
import java.sql.*; %cd]xQpCp
/** \CDAFu#
* rr>IKyI'
* @author Iw*C*%}[Z
*/ % dYI5U89
public class CountControl{
+Bn?-{h=
private static long lastExecuteTime=0;//上次更新时间 sI4QI\*4
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 4t*<+H%
/** Creates a new instance of CountThread */ x6jm-n
public CountControl() {} do*Wx2:R
public synchronized void executeUpdate(){ |<'10
Connection conn=null; &'NQ)Dn
PreparedStatement ps=null; @X|ok*v`
try{ Px$'(eMj^3
conn = DBUtils.getConnection(); L#[HnsLp_
conn.setAutoCommit(false); 65uZLsQ
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 01-p
`H+
for(int i=0;i<CountCache.list.size();i++){ )'w]YIv9
CountBean cb=(CountBean)CountCache.list.getFirst(); @H3|u`6V
CountCache.list.removeFirst(); 2,+@#q
ps.setInt(1, cb.getCountId()); D.
77WjwQ
ps.executeUpdate();⑴ &8zk3
//ps.addBatch();⑵ XpOCQyFnM
} l#mtND3
//int [] counts = ps.executeBatch();⑶ vW9^hbdx
conn.commit(); $`ON!,oa
}catch(Exception e){ RLv&,$$0
e.printStackTrace(); y+l<vJu
} finally{ $B*qNYpPy.
try{ `Nkx7Z~w:
if(ps!=null) { #3YdjU3w
ps.clearParameters(); R,uJK)m
ps.close(); 69N1 mP
ps=null; 0qOM78rE
} Z=0iPy,m>
}catch(SQLException e){} "MW55OWYU
DBUtils.closeConnection(conn); //VG1@vaVX
} (69kvA&|q
} \?J=mE@;1
public long getLast(){ l)|z2H
return lastExecuteTime; w($XEv;
} qdKh6{
public void run(){ 4U_rB9K$
long now = System.currentTimeMillis(); \XZU'JIO
if ((now - lastExecuteTime) > executeSep) {
5L/Yi
//System.out.print("lastExecuteTime:"+lastExecuteTime); |L*6x
S[
//System.out.print(" now:"+now+"\n"); c>M_?::)0
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); C,V|TF.i2
lastExecuteTime=now;
c"6Kd$?M
executeUpdate(); N)`tI0/W
} ^w.k^U=B
else{ \xy:6gd:
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); n\~"Wim<b
} Z`e$~n(Bh
} E>o&GYc
} L2:oZ&:u`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 [I#Q
NHst7$Y<
类写好了,下面是在JSP中如下调用。 0:~gW#lD
5;r({J
<% ZS07_6.~
CountBean cb=new CountBean(); w; yar=n
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); rCV$N&rK
CountCache.add(cb); fo/(()
out.print(CountCache.list.size()+"<br>"); &Z#Vw.7U
CountControl c=new CountControl(); "i;*\+x
c.run(); QSlf=VK*y
out.print(CountCache.list.size()+"<br>"); EfMG(oI
%>