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: r'!L}^n
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CountBean.java 1vw[{.wC
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/* aQzDOeTi
* CountData.java ,gAa9
* oD1rt>k
* Created on 2007年1月1日, 下午4:44 LsB|}_j7
* aX
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* To change this template, choose Tools | Options and locate the template under r6_g/7.-
* the Source Creation and Management node. Right-click the template and choose -\=s+n_ZP?
* Open. You can then make changes to the template in the Source Editor. F/33#
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*/ VZhtx)
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package com.tot.count; +S/OMkC
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/** r{oRN
* *?Hc8y-dG,
* @author aY:u-1
*/ 5dwC~vn}c
public class CountBean { Lg6;FbY?
private String countType; eO7 )LM4
int countId; 2>`m1q:
/** Creates a new instance of CountData */ cg`bbZ
public CountBean() {} h"O4r8G}
public void setCountType(String countTypes){ >JOEp0J
this.countType=countTypes; ,j3Yvn W
} >~_oSC)E
public void setCountId(int countIds){ {\:"OcP #
this.countId=countIds; |.]sL0;4Z
} 3i\<#{
public String getCountType(){ mO#62e4C
return countType; ,%Go.3i[
} _=Y?' gHH
public int getCountId(){ mf4C68DI@u
return countId; N{kp^Byim0
} jimWLF5Q5"
} 6l Suzu
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CountCache.java y}5:CZ
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/* t[=-4;
* CountCache.java ^&[Z@*A8#
* 2g0_[$[m
* Created on 2007年1月1日, 下午5:01 xlKg0&D
* mCb1^Y
* To change this template, choose Tools | Options and locate the template under PCqE9B)l
* the Source Creation and Management node. Right-click the template and choose #/"?.Z;SSH
* Open. You can then make changes to the template in the Source Editor. )h0
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*/ B7QuSo//
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package com.tot.count; |f+`FOliP
import java.util.*; /+
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/** 58]C``u@Y
* bf4QW JZD
* @author A!GQ4.~%
*/ k[ZkVwx
public class CountCache { 5EX
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public static LinkedList list=new LinkedList(); 4CH/~b1(
/** Creates a new instance of CountCache */ .:wo
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public CountCache() {} W)~}o<a)[
public static void add(CountBean cb){ @1c[<3xJT
if(cb!=null){ g.,_E4L
list.add(cb); q0t}
} eVRPjVzQ'Q
} 9_Ws8nE
} ,SV34+(
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CountControl.java ]K0G!T R<
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/* i:/Ws1=q
* CountThread.java q+ZN$4 m
* O yG#
* Created on 2007年1月1日, 下午4:57 *4HogC
* ~~iFs ,9
* To change this template, choose Tools | Options and locate the template under p uOAt
* the Source Creation and Management node. Right-click the template and choose a[Y\5Ojm
* Open. You can then make changes to the template in the Source Editor. hI6Tp>b*~
*/ H$M{thW
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package com.tot.count; 1`q>*S](
import tot.db.DBUtils; +3d.JQoKl
import java.sql.*; OAiSE`
/** v$d^>+Y#
* &@U)
* @author -]~KQvIH!
*/ *S= c0
public class CountControl{ -\I".8"YE
private static long lastExecuteTime=0;//上次更新时间 hVGK%HCz&
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 @9AK!I8f
/** Creates a new instance of CountThread */ ]1)#Y
public CountControl() {} )RCva3Ul
public synchronized void executeUpdate(){ yM
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Connection conn=null; opIbs7k-
PreparedStatement ps=null; w l#jSj%pd
try{ {b,#l]v
conn = DBUtils.getConnection(); P9f,zM-
conn.setAutoCommit(false); Ox%.We5
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ]_js-+w6
for(int i=0;i<CountCache.list.size();i++){ ]!'}{[1}
CountBean cb=(CountBean)CountCache.list.getFirst(); L (@".{T
CountCache.list.removeFirst(); EC8 Fapy
ps.setInt(1, cb.getCountId()); \Y$@$)
ps.executeUpdate();⑴ D:=Q)Uh0I
//ps.addBatch();⑵ ^&!iq K2o
} /cC4K\M
//int [] counts = ps.executeBatch();⑶ H[J5A2b
conn.commit(); ., =\/ C<
}catch(Exception e){ c2~oPUj
e.printStackTrace(); .|c=]_{
} finally{ [,TK"
try{ o?`^
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if(ps!=null) { L7"B`oa(p
ps.clearParameters(); ^@f-Ni\
ps.close(); :=oIvSnh
ps=null; XY)I ~6$Y
} ,sZ)@?e
}catch(SQLException e){} rp_Aw
DBUtils.closeConnection(conn); c 4
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} &s~b1Va
} *z
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public long getLast(){ Xf6\{
return lastExecuteTime; S]g`Ds<
} 9Ac4'L
public void run(){ bFB.hkTP
long now = System.currentTimeMillis(); g$T%
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if ((now - lastExecuteTime) > executeSep) { HLb`'TC3r+
//System.out.print("lastExecuteTime:"+lastExecuteTime); |_u|Td(n
//System.out.print(" now:"+now+"\n"); m
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Jq8:33s
lastExecuteTime=now; A|<i7QVY
executeUpdate(); .`~=1
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} Xmv^O
else{ Z" N}f
,
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); M-zqD8D
} I*EHZctH
} c+N\uG4
} %'&_Po\
//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 !f01.Tq8
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类写好了,下面是在JSP中如下调用。 z+{Q(8'b]
v<:/u(i
<% %ou@Y`
CountBean cb=new CountBean(); <G /a-Z
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); cIQe^C
CountCache.add(cb); Rc#c^F<
out.print(CountCache.list.size()+"<br>"); ?X nKKw\
CountControl c=new CountControl(); #<81`%
c.run(); LPS]TG\
out.print(CountCache.list.size()+"<br>"); 2|JtRE+
%>