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: n%o5kVx0
($; 77fPR
CountBean.java %,@e^3B
zkuU5O
/* eo?;`7
* CountData.java o.!~8mD
* 7`zHX&-W
* Created on 2007年1月1日, 下午4:44 ?IqQ-C)6D
* OuID%p"O
* To change this template, choose Tools | Options and locate the template under ogHCt{'
* the Source Creation and Management node. Right-click the template and choose Tz8PS k1[
* Open. You can then make changes to the template in the Source Editor. v50bdj9}k
*/ #mCL) [
bB1UZ O
package com.tot.count; Vr`R>S,-
NflD/q/ L
/** ;S^'V
* q$Zh@
* @author rrBsb -
*/ xSsa(b
public class CountBean { --HZX
private String countType; AQ,'
6F9
int countId; '$ =>
/** Creates a new instance of CountData */ $j5K8Ad
public CountBean() {} emqZztccZ
public void setCountType(String countTypes){ ^6MU
0Q2
this.countType=countTypes; p'*>vk
} G\Cp7:j}
public void setCountId(int countIds){ Eg#K.5hJ
this.countId=countIds; wnEyl[ac
} 8pIP
public String getCountType(){ lm-dW'7&
return countType; P3x= 8_#
} [B#R94
public int getCountId(){ 'MUv5Th
return countId; m.#
VYN`+A
} bYpntV
} hKLCJ#T
|,gc_G
CountCache.java e,vvzso
1PQ~jfGi
/* .f%fHj
* CountCache.java K1"*.\?F
* ?(Dq ?-.
* Created on 2007年1月1日, 下午5:01 VM
GS[qrG
*
-D
* To change this template, choose Tools | Options and locate the template under !;Yg/'vD-
* the Source Creation and Management node. Right-click the template and choose eg\v0Y!rI
* Open. You can then make changes to the template in the Source Editor. cl[BF'.H
*/ >z{d0{\
XHK<AO^
package com.tot.count; }Jy8.<Gd^
import java.util.*; 5cL83FQh
/** 1 d}Z(My
* u~7hWiY<2
* @author H]{v;;'~
*/ C*)3e*T*
public class CountCache { r3&G)g=u
public static LinkedList list=new LinkedList(); |[<_GQl
/** Creates a new instance of CountCache */ Fq~yL!#!
public CountCache() {} ,Ys %:>?
public static void add(CountBean cb){ ZRh~`yy
if(cb!=null){ eL10Q(;P`
list.add(cb); 3G,Oba[$<
} Bu<M\w?7Y
} ;4R$g5-4X
} ;f0I
8i,JN
"pi=$/RD9
CountControl.java ]HKQDc'
u]<,,
/* 5nv#+ap1 "
* CountThread.java @r/#-?W
* :)wy.r;N
* Created on 2007年1月1日, 下午4:57 ieDk ;
* \r;#g{
_
* To change this template, choose Tools | Options and locate the template under |oH,
* the Source Creation and Management node. Right-click the template and choose #%a;"w
* Open. You can then make changes to the template in the Source Editor. jaTh^L
*/ &zl|87M
5{|7$VqPF
package com.tot.count; ck ]Do!h
import tot.db.DBUtils; BgurzS4-
import java.sql.*; nhB1D-
/** gp};D
* @|
M|+k3
* @author @Lpq~ 1eZB
*/ <Swt);
public class CountControl{ q@QksAq
private static long lastExecuteTime=0;//上次更新时间 rn/ /%
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 <r.)hT"0
/** Creates a new instance of CountThread */ lP[w?O
public CountControl() {} Y}t \4 di
public synchronized void executeUpdate(){ ,X[ktz
Connection conn=null; ^crCy-`#
PreparedStatement ps=null; !O+)sbd<
try{ "cE7
5
conn = DBUtils.getConnection(); dsb `xw
conn.setAutoCommit(false); ^=BTz9QM
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); q-[@$9AS
for(int i=0;i<CountCache.list.size();i++){ .Xfq^'I[
CountBean cb=(CountBean)CountCache.list.getFirst(); ^W`<gR
CountCache.list.removeFirst(); 5A)2} D]
ps.setInt(1, cb.getCountId()); |4)>:d
ps.executeUpdate();⑴ HmiR.e%<b
//ps.addBatch();⑵ nHnK)9\ N
} $:=A'd2
//int [] counts = ps.executeBatch();⑶ 7]U"Z*
conn.commit(); h;C5hU4P
}catch(Exception e){ L"E7#}
e.printStackTrace(); <;9I@VYK
} finally{ yQ_B)b
try{ r54&XE]O
if(ps!=null) { !POl;%\
ps.clearParameters(); 9A/\h3HrJ
ps.close(); Hbj,[$Jb
ps=null; #X%~B'
} }6p@lla,%]
}catch(SQLException e){} PXK7b2fE.
DBUtils.closeConnection(conn); \l'm[jy>
} Lz`E;k^
} \s/s7y6b+
public long getLast(){ %}SGl${-
return lastExecuteTime; 0ZT5bg_M
} MuYk};f
public void run(){ .GsV>H
long now = System.currentTimeMillis(); m;H.#^b*
if ((now - lastExecuteTime) > executeSep) { c&r70L,
//System.out.print("lastExecuteTime:"+lastExecuteTime); j2Cks_$:
//System.out.print(" now:"+now+"\n"); 8|):`u
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); > A Khf
lastExecuteTime=now; $Z!`Hb
executeUpdate(); <>dT64R|
} .R)D3NZp
else{ j|4<i9^}
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); D8inB+/-
} KX76UW
} HFKfkAl
} ) brVduB
//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_s_p
Y#!UPhg<
类写好了,下面是在JSP中如下调用。 4E;VM{
[="e
ziM{
<% h hG4-HD
CountBean cb=new CountBean(); zO~8?jDN4|
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ]p _L)
CountCache.add(cb); ta35 K"
out.print(CountCache.list.size()+"<br>"); DwaBdN[!7
CountControl c=new CountControl(); OglEt[ "
c.run(); n)L*
out.print(CountCache.list.size()+"<br>"); aO]ZZleNS
%>