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: E>|X'I?r^
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CountBean.java M}V!;o<t^
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/* gVOAB-nw
* CountData.java 0<-E)\:[g
* 4\Y5RfLB_
* Created on 2007年1月1日, 下午4:44 0+* NHiH
* pi?MAE*f
* To change this template, choose Tools | Options and locate the template under J{1H$[W~}
* the Source Creation and Management node. Right-click the template and choose 7~mhWPzMwB
* Open. You can then make changes to the template in the Source Editor. 7#0buXBg
*/ a4__1N^Qj
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package com.tot.count; V}#X'~Ob
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/** ){5Nod{}a
* k||t<&`Ze
* @author }oRBQP^&K
*/ ;/j2(O^
public class CountBean { >CqzC8JF
private String countType; "tzu.V-
int countId; N7+L@CC6T
/** Creates a new instance of CountData */ 6QX m]<
public CountBean() {} .:r~?$(
public void setCountType(String countTypes){ ?dgyi4J?=`
this.countType=countTypes; 0Ds3wNz
} 20;9XJmjl
public void setCountId(int countIds){ !mmMAsd,
this.countId=countIds; }'$PYAf6
} _fHml
public String getCountType(){ 52e>f5m.
return countType; <W"W13*j!
} O,Q.-
public int getCountId(){ hJ}i+[~be
return countId; j<B9$8x&
} vwU1}H
} >.iF,[.[F<
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CountCache.java Q5+1'mzAB
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/* J?QS7#!%
* CountCache.java { qNPhi
* m+TAaK
* Created on 2007年1月1日, 下午5:01 1UP=(8j/
* tJ\
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* To change this template, choose Tools | Options and locate the template under a#YK1n[!
* the Source Creation and Management node. Right-click the template and choose zfeT>S+
* Open. You can then make changes to the template in the Source Editor. !@ ^6/=
*/ J7`mEL>?
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package com.tot.count; *;o%*:
import java.util.*; 6p9fq3~7Y
/** HEF
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* g'(bk@<BP
* @author fE-R(9K
*/ 6_Fr \H
public class CountCache {
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public static LinkedList list=new LinkedList(); :
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/** Creates a new instance of CountCache */ Z}J5sifr
public CountCache() {} 513,k$7
public static void add(CountBean cb){ 4Z"}W!A
if(cb!=null){ h.jJAVPi
list.add(cb); 4l$OO;B
} }aZuCe_
} >HP
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} l|P"^;*zq
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CountControl.java p)y5[HX
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/* [FO4x`
* CountThread.java c|&3e84U
* 6hxZ5&;(*
* Created on 2007年1月1日, 下午4:57 a+w2cN'
* v/+ <YU
* To change this template, choose Tools | Options and locate the template under Re$h6sh
* the Source Creation and Management node. Right-click the template and choose z5E%*]
* Open. You can then make changes to the template in the Source Editor. (Rw<1q`,
*/ KGz Nj%
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package com.tot.count; Bm$|XS3cD
import tot.db.DBUtils; *]$B 9zVs!
import java.sql.*; DXs an
/** )9]a
* ".?4`@7F\
* @author [C'bfX5HB5
*/ n|( lPbD
public class CountControl{ wPlM=
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private static long lastExecuteTime=0;//上次更新时间 jm}CrqU
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Y{YbKKM
/** Creates a new instance of CountThread */ 2HE@!*z9H
public CountControl() {} Pe`(9&iT.
public synchronized void executeUpdate(){ C8U3+ s
Connection conn=null; sg2;"E@
PreparedStatement ps=null; i}-uK,^
try{ d54iZ`
conn = DBUtils.getConnection(); @(t3<g
conn.setAutoCommit(false); m{\
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); uzYB`H<
for(int i=0;i<CountCache.list.size();i++){ VmS_(bM
CountBean cb=(CountBean)CountCache.list.getFirst(); ul~ux$a
CountCache.list.removeFirst(); &N~Eu-@b
ps.setInt(1, cb.getCountId()); Q_5l.M/9]
ps.executeUpdate();⑴ 82r8K|L.<y
//ps.addBatch();⑵ -$Oh.B`i
} c4Ebre-Oa
//int [] counts = ps.executeBatch();⑶ J<$@X JLS
conn.commit(); J=g)rd[`
}catch(Exception e){ O2w-nd74U
e.printStackTrace(); zF1!a
} finally{ pv_o4qEN
try{ 3:J>-MO
if(ps!=null) { f1 ;
ps.clearParameters(); VD;*UkapZx
ps.close(); ^HKXm#vAB
ps=null; oaIk1U;g
} ~k"+5bHa*
}catch(SQLException e){} d:=' Xs
DBUtils.closeConnection(conn); t R^f]+Up
} LrB
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} HIg2y
public long getLast(){ '7iz5wC#
return lastExecuteTime; ~Amq1KU*Z
} BoD{fg
public void run(){ D6"=2XR4n
long now = System.currentTimeMillis(); -l^<[%
if ((now - lastExecuteTime) > executeSep) { j*{0<hZb}
//System.out.print("lastExecuteTime:"+lastExecuteTime); !~ox;I}S
//System.out.print(" now:"+now+"\n"); ;Afz`Se1@
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); p~D}Iyww1_
lastExecuteTime=now; djd/QAfSC
executeUpdate(); )U/jD
} VYk:c`E
else{ J9^NHU
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); #Hw|P
} Cf%
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} YT\`R
} ,f
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//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 /*0t_
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类写好了,下面是在JSP中如下调用。 Vk2$b{VdF
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<% vFPY|Vzh
CountBean cb=new CountBean(); KC/O
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); {6i|"5_j
CountCache.add(cb); #;[G>-tC
out.print(CountCache.list.size()+"<br>"); [vg&E
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CountControl c=new CountControl(); @N*|w
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c.run(); TnrBHaxbo4
out.print(CountCache.list.size()+"<br>"); JEUU~L;
%>