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: kTb.I;S
K{.s{;#
CountBean.java #+N\u*-S
VUC
/* ~=h]r/b< U
* CountData.java Z4A
a
* r(h&=&T6
* Created on 2007年1月1日, 下午4:44 kMWu%,s4
* jb~a z
* To change this template, choose Tools | Options and locate the template under WMnR+?q
* the Source Creation and Management node. Right-click the template and choose $e&( ncM
* Open. You can then make changes to the template in the Source Editor. c9-$td&
*/ j/4N
7F;"=DarOE
package com.tot.count; /e1m1 B
`au('
xi<
/** %^n9Z/I
* D
M(WYL{
* @author !8yw!hA
*/ et(/`
public class CountBean { ,mEFp_a+
private String countType; @qmONQ eb
int countId; k$UgTZ
/** Creates a new instance of CountData */ lTJ1]7)
public CountBean() {} xB_F?d40T5
public void setCountType(String countTypes){ 1|bu0d\]
this.countType=countTypes; ;j])h!8X
} jY
EB`&
public void setCountId(int countIds){ &dF$:$'s
this.countId=countIds; |};]^5s9
} mA}-hR%
public String getCountType(){ &f'\9lO
return countType; )W95)]
} 'c<vj
jIg
public int getCountId(){ \?c0XD
return countId; bq[j4xH0X
} Ni*f1[sI<
} 2ME"=!&5
^ j;HYs_
CountCache.java Eb SH)aR
OLUQjvnU
/* 1{4d)z UB
* CountCache.java x- kCNy
* lA {
* Created on 2007年1月1日, 下午5:01 H1_XEcaM+*
* _
vVw2HH
* To change this template, choose Tools | Options and locate the template under 4)BZ%1+
* the Source Creation and Management node. Right-click the template and choose h^^zR)EVb
* Open. You can then make changes to the template in the Source Editor. SQ|pH"
*/ t1?e$s
r?Jxl<
package com.tot.count; |7]7~ 6l
import java.util.*; VvN52
qeL
/** -QjdL9\[c7
* h=SQ]nV{
* @author $r|R`n =
*/ X).UvPZ/
public class CountCache { F+PIZ%
public static LinkedList list=new LinkedList(); yi<&'L;
/** Creates a new instance of CountCache */ F>jPr8&
public CountCache() {} Mm`jk%:%]
public static void add(CountBean cb){ E]w1!Ah M
if(cb!=null){ g]85[xz
list.add(cb); H+vONg
} +jYO?uaT
} Pc>$[kT0
} pw{3I 2Ix
r|4jR6%<'m
CountControl.java 'ah|cMRn
c_c]0Tm
/* HmKvu"3
* CountThread.java B04%4N.g"X
* B+S
&vV
* Created on 2007年1月1日, 下午4:57 *%1:="W*|
* )V~Fl$A
* To change this template, choose Tools | Options and locate the template under L;/#D>U(
* the Source Creation and Management node. Right-click the template and choose 6cz%>@
* Open. You can then make changes to the template in the Source Editor. 4r#O._Z
*/ 0/hX3h
'`?\CXX
package com.tot.count; SjD,
import tot.db.DBUtils; !Sr^4R +Z
import java.sql.*; 9UTWq7KJ
/** 2uFaAAT
* E{gu39 D
* @author /*p4(D_A
*/ sj a;NL
public class CountControl{ W!q'wrIx(
private static long lastExecuteTime=0;//上次更新时间 rubqk4
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 nN>D=a"&F
/** Creates a new instance of CountThread */ q88p~Ccoa
public CountControl() {} HVz-i{M
public synchronized void executeUpdate(){ Pd!;z=I
Connection conn=null; zMs]9o
PreparedStatement ps=null; NHA
2 i
try{ qY\zZ
conn = DBUtils.getConnection(); jENarB^As
conn.setAutoCommit(false); g!~&PT)*
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); h95C4jBE
for(int i=0;i<CountCache.list.size();i++){ C0/s/p'
CountBean cb=(CountBean)CountCache.list.getFirst(); ka{9{/dz3
CountCache.list.removeFirst(); X5 lB],t"=
ps.setInt(1, cb.getCountId()); hKtOh
ps.executeUpdate();⑴ I9*o[Jp5
//ps.addBatch();⑵ dvxD{UH
} l2GMVAca
//int [] counts = ps.executeBatch();⑶ d=WC1"
conn.commit(); 6CO>Tg:%
}catch(Exception e){ %8/Gsu;
e.printStackTrace(); eHK}U+"\
} finally{ Hf+A52lrf
try{ AKx\U?ei7
if(ps!=null) { hor ok:{
ps.clearParameters(); ?I}jsm1)
ps.close(); /'
L20aN2
ps=null; X0b :Oiw
} p9R`hgx
}catch(SQLException e){} DamLkkoA
DBUtils.closeConnection(conn); j)Kk:BFFY
} n4YEu\*
} QnZR
public long getLast(){ ~c
;7me.
return lastExecuteTime; ({D.oS
} q9pBS1Ej
public void run(){ ,iCd6M{
long now = System.currentTimeMillis(); H(Mlf
if ((now - lastExecuteTime) > executeSep) { V5KAiG<d
//System.out.print("lastExecuteTime:"+lastExecuteTime); hw_7N)}
//System.out.print(" now:"+now+"\n"); ,8o]XFOr
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); h 7kyz
lastExecuteTime=now; GEA@AD=^f
executeUpdate(); :*tv`:;p
} *Dh.'bB!
else{ ig; ~
T
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); +>z/54R
} gtJ^8khME
} @l"GfDfL9
} {ZbeF#*"
//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 h1fJ`WT6,
fouy??
类写好了,下面是在JSP中如下调用。 M(Jf&h4b
tt|U,o
<% #`z!f0
P
CountBean cb=new CountBean(); 4TG|
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); )~d2`1zGS
CountCache.add(cb); "$0f.FO:i
out.print(CountCache.list.size()+"<br>"); $0LlaN@e
CountControl c=new CountControl(); 6e |
c.run(); cJ]`/YJ
out.print(CountCache.list.size()+"<br>"); =6
%>